Giuseppe Salamanna Univ di Roma ldquoLa Sapienzardquo amp INFN Romafor the CDF Collaboration

BEACH 2006 July 2006 Lancaster (UK)

Measurement of Bs

oscillations at CDF

2

OutlineMotivations ΔMs and the Unitarity Triangle Analysis details Trigger and reconstruction Lifetime measurements and biases Flavour tagging(Some) Statistical details and expected significance Results for ΔMs Interpretation and derived constraints

Paper submitted to PRL hep-ex0606027

3

Why ΔMs Observation of a quantum phenomenon flavour oscillations via a ΔF = 2 Box diagram

222

222

||6

)(tbtqBBB

tWFq VVBfm

xSmGM

qqq

b s

bs

0sB

0sB u c t u c t

tsV

tbV

tbV

tsV

W

W

bullThe only relevant diagram has b coupling with top

bullNew (s)particles in the loop

Form factors and B-parameters from Lattice calculations have high uncertainty rarr Vtd known only at ~15 level

Mixing involves CKM elements rarr measuring ΔMq constraintsthe unitarity triangle

4

UT and constraint from mixing

ΔMd onlyLimit on ΔMs ΔMs ΔMd

From lattice

bull Ratio equiv ξ2 is better

calculated than single factors

bull ξ = 1210 + 0047-0035

(MOkamoto hep-lat0510113)

clubs Measuring ΔMs ΔMd

returns Vts Vtd with ~4 error from theory

ss

dd

Bf

Bf2

2

UP TO WINTER lsquo06bullΔMs ge 166 ps-1 (LEP+SLD+Tevatron I and II)

bullExpected value (UT fit utfitroma1infnit) ΔMs (SM) = 215 plusmn 26 ps -1

ΔMs in [167 269] 95 CLclubs LARGER ΔMs could indicate NP contribrsquos

5

Final stateReconstruct final states from both Semileptonic (high statistics but missing kinematics) and Hadronic (fully reconstructed best ct resolution)

Lifetime measurement Hadronic decay length measured with better resolution than Semileptonic

Flavour tagging Tag the flavour of the mixing B candidate using both

correlation with fragmentation tracks AND flavour of other b (incoherent b-b production)

Want to measurehellipso how

6

Amplitude ScanIntroduce ldquoAmplituderdquo in Likelihood

tMDAeL ttsig cos1

1

Fit A for fixed ΔM

A consistent with1 if mixing detected at a given ΔM

0 if no mixing at a given ΔM

Limit where A+1645σA = 1Sensitivity 1645σA = 1

Example of amplitude scanWorld Average Fall lsquo05

7

BS

Se

DS tsM

A

2

)(22

21

Measurement significanceThe expression of the statistical Significance of a mixing measurement is given by

Signal

(b-flavour at decay tagged)

Fraction of S withinfo also on flavour at creation

Experimental time resolutionexponentially dilutes a measurement

Trigger-challengeto collect Ssuppressing B

Significance exponentially reduced at higher ΔMs hellip

hellip|Vts| gtgt |Vtd| Ms ~40Md

8

Final states selection and yields

9

Hadronic signalsL = 1 fb-1

N(Bs) asymp 3600

)(

)(00

0

ss

ssss

DB

DDDB

ldquoSatellitesrdquo

(Not used in this analysis)

Bs0rarr Ds

- (3)π+ (Ds

- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π

1570 plusmn 43

Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32

Bs rarr Ds π Ds rarr 3π 612 plusmn 37

Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37

Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26

bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with

bull d0 gt 120 μm (τ(B)asymp15ps)

bullPt gt 55 GeVc

10

Semileptonic signals

Bs0rarr Ds

-() ℓ+ν X (Ds

- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)

bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates

11

Lifetime measurement

12

Hadronic Lifetime Results

Modecτ [μm]

(stat only)

B0D- + 4911 plusmn 51

B-D0 - 4521 plusmn 51

BsDs() π 461 plusmn 12

World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps

bullDetailed simulation to correct for trigger bias

on the selection of the B decay lengthbullSyst on trigger efficiency negligible

for mixing measurements

Excellent agreement

13

Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2

2

)( t

t

M

eD

2

20

p

ct pctct

Vertex resolution(constant)

Momentum resolution

(~ct)

bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies

bullCalibrate by fitting for lifetime of B0-like decays

osc period at Ms = 18 ps-1

Hadronic-like

Semileptonic-likeltσppgt asymp15

CDF II

14

Flavour tagging

15

Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently

εD2 Hadronic ()εD2 Semileptonic

()

Muon 048 006 (stat) 062 003 (stat)

Electron 009 003 (stat) 010 001 (stat)

JQSecVtx 030 004 (stat) 027 002 (stat)

JQDisplrsquod trk

046 005 (stat) 034 002 (stat)

JQHigh pT 014 003 (stat) 011 001 (stat)

Total OST 147 010 (stat) 144 004 (stat)

SSKT 35 05 (syst) 40 06 (syst)

Efficiency

Dilution = 1-2bullmistag rate

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

2

OutlineMotivations ΔMs and the Unitarity Triangle Analysis details Trigger and reconstruction Lifetime measurements and biases Flavour tagging(Some) Statistical details and expected significance Results for ΔMs Interpretation and derived constraints

Paper submitted to PRL hep-ex0606027

3

Why ΔMs Observation of a quantum phenomenon flavour oscillations via a ΔF = 2 Box diagram

222

222

||6

)(tbtqBBB

tWFq VVBfm

xSmGM

qqq

b s

bs

0sB

0sB u c t u c t

tsV

tbV

tbV

tsV

W

W

bullThe only relevant diagram has b coupling with top

bullNew (s)particles in the loop

Form factors and B-parameters from Lattice calculations have high uncertainty rarr Vtd known only at ~15 level

Mixing involves CKM elements rarr measuring ΔMq constraintsthe unitarity triangle

4

UT and constraint from mixing

ΔMd onlyLimit on ΔMs ΔMs ΔMd

From lattice

bull Ratio equiv ξ2 is better

calculated than single factors

bull ξ = 1210 + 0047-0035

(MOkamoto hep-lat0510113)

clubs Measuring ΔMs ΔMd

returns Vts Vtd with ~4 error from theory

ss

dd

Bf

Bf2

2

UP TO WINTER lsquo06bullΔMs ge 166 ps-1 (LEP+SLD+Tevatron I and II)

bullExpected value (UT fit utfitroma1infnit) ΔMs (SM) = 215 plusmn 26 ps -1

ΔMs in [167 269] 95 CLclubs LARGER ΔMs could indicate NP contribrsquos

5

Final stateReconstruct final states from both Semileptonic (high statistics but missing kinematics) and Hadronic (fully reconstructed best ct resolution)

Lifetime measurement Hadronic decay length measured with better resolution than Semileptonic

Flavour tagging Tag the flavour of the mixing B candidate using both

correlation with fragmentation tracks AND flavour of other b (incoherent b-b production)

Want to measurehellipso how

6

Amplitude ScanIntroduce ldquoAmplituderdquo in Likelihood

tMDAeL ttsig cos1

1

Fit A for fixed ΔM

A consistent with1 if mixing detected at a given ΔM

0 if no mixing at a given ΔM

Limit where A+1645σA = 1Sensitivity 1645σA = 1

Example of amplitude scanWorld Average Fall lsquo05

7

BS

Se

DS tsM

A

2

)(22

21

Measurement significanceThe expression of the statistical Significance of a mixing measurement is given by

Signal

(b-flavour at decay tagged)

Fraction of S withinfo also on flavour at creation

Experimental time resolutionexponentially dilutes a measurement

Trigger-challengeto collect Ssuppressing B

Significance exponentially reduced at higher ΔMs hellip

hellip|Vts| gtgt |Vtd| Ms ~40Md

8

Final states selection and yields

9

Hadronic signalsL = 1 fb-1

N(Bs) asymp 3600

)(

)(00

0

ss

ssss

DB

DDDB

ldquoSatellitesrdquo

(Not used in this analysis)

Bs0rarr Ds

- (3)π+ (Ds

- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π

1570 plusmn 43

Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32

Bs rarr Ds π Ds rarr 3π 612 plusmn 37

Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37

Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26

bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with

bull d0 gt 120 μm (τ(B)asymp15ps)

bullPt gt 55 GeVc

10

Semileptonic signals

Bs0rarr Ds

-() ℓ+ν X (Ds

- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)

bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates

11

Lifetime measurement

12

Hadronic Lifetime Results

Modecτ [μm]

(stat only)

B0D- + 4911 plusmn 51

B-D0 - 4521 plusmn 51

BsDs() π 461 plusmn 12

World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps

bullDetailed simulation to correct for trigger bias

on the selection of the B decay lengthbullSyst on trigger efficiency negligible

for mixing measurements

Excellent agreement

13

Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2

2

)( t

t

M

eD

2

20

p

ct pctct

Vertex resolution(constant)

Momentum resolution

(~ct)

bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies

bullCalibrate by fitting for lifetime of B0-like decays

osc period at Ms = 18 ps-1

Hadronic-like

Semileptonic-likeltσppgt asymp15

CDF II

14

Flavour tagging

15

Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently

εD2 Hadronic ()εD2 Semileptonic

()

Muon 048 006 (stat) 062 003 (stat)

Electron 009 003 (stat) 010 001 (stat)

JQSecVtx 030 004 (stat) 027 002 (stat)

JQDisplrsquod trk

046 005 (stat) 034 002 (stat)

JQHigh pT 014 003 (stat) 011 001 (stat)

Total OST 147 010 (stat) 144 004 (stat)

SSKT 35 05 (syst) 40 06 (syst)

Efficiency

Dilution = 1-2bullmistag rate

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

3

Why ΔMs Observation of a quantum phenomenon flavour oscillations via a ΔF = 2 Box diagram

222

222

||6

)(tbtqBBB

tWFq VVBfm

xSmGM

qqq

b s

bs

0sB

0sB u c t u c t

tsV

tbV

tbV

tsV

W

W

bullThe only relevant diagram has b coupling with top

bullNew (s)particles in the loop

Form factors and B-parameters from Lattice calculations have high uncertainty rarr Vtd known only at ~15 level

Mixing involves CKM elements rarr measuring ΔMq constraintsthe unitarity triangle

4

UT and constraint from mixing

ΔMd onlyLimit on ΔMs ΔMs ΔMd

From lattice

bull Ratio equiv ξ2 is better

calculated than single factors

bull ξ = 1210 + 0047-0035

(MOkamoto hep-lat0510113)

clubs Measuring ΔMs ΔMd

returns Vts Vtd with ~4 error from theory

ss

dd

Bf

Bf2

2

UP TO WINTER lsquo06bullΔMs ge 166 ps-1 (LEP+SLD+Tevatron I and II)

bullExpected value (UT fit utfitroma1infnit) ΔMs (SM) = 215 plusmn 26 ps -1

ΔMs in [167 269] 95 CLclubs LARGER ΔMs could indicate NP contribrsquos

5

Final stateReconstruct final states from both Semileptonic (high statistics but missing kinematics) and Hadronic (fully reconstructed best ct resolution)

Lifetime measurement Hadronic decay length measured with better resolution than Semileptonic

Flavour tagging Tag the flavour of the mixing B candidate using both

correlation with fragmentation tracks AND flavour of other b (incoherent b-b production)

Want to measurehellipso how

6

Amplitude ScanIntroduce ldquoAmplituderdquo in Likelihood

tMDAeL ttsig cos1

1

Fit A for fixed ΔM

A consistent with1 if mixing detected at a given ΔM

0 if no mixing at a given ΔM

Limit where A+1645σA = 1Sensitivity 1645σA = 1

Example of amplitude scanWorld Average Fall lsquo05

7

BS

Se

DS tsM

A

2

)(22

21

Measurement significanceThe expression of the statistical Significance of a mixing measurement is given by

Signal

(b-flavour at decay tagged)

Fraction of S withinfo also on flavour at creation

Experimental time resolutionexponentially dilutes a measurement

Trigger-challengeto collect Ssuppressing B

Significance exponentially reduced at higher ΔMs hellip

hellip|Vts| gtgt |Vtd| Ms ~40Md

8

Final states selection and yields

9

Hadronic signalsL = 1 fb-1

N(Bs) asymp 3600

)(

)(00

0

ss

ssss

DB

DDDB

ldquoSatellitesrdquo

(Not used in this analysis)

Bs0rarr Ds

- (3)π+ (Ds

- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π

1570 plusmn 43

Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32

Bs rarr Ds π Ds rarr 3π 612 plusmn 37

Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37

Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26

bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with

bull d0 gt 120 μm (τ(B)asymp15ps)

bullPt gt 55 GeVc

10

Semileptonic signals

Bs0rarr Ds

-() ℓ+ν X (Ds

- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)

bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates

11

Lifetime measurement

12

Hadronic Lifetime Results

Modecτ [μm]

(stat only)

B0D- + 4911 plusmn 51

B-D0 - 4521 plusmn 51

BsDs() π 461 plusmn 12

World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps

bullDetailed simulation to correct for trigger bias

on the selection of the B decay lengthbullSyst on trigger efficiency negligible

for mixing measurements

Excellent agreement

13

Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2

2

)( t

t

M

eD

2

20

p

ct pctct

Vertex resolution(constant)

Momentum resolution

(~ct)

bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies

bullCalibrate by fitting for lifetime of B0-like decays

osc period at Ms = 18 ps-1

Hadronic-like

Semileptonic-likeltσppgt asymp15

CDF II

14

Flavour tagging

15

Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently

εD2 Hadronic ()εD2 Semileptonic

()

Muon 048 006 (stat) 062 003 (stat)

Electron 009 003 (stat) 010 001 (stat)

JQSecVtx 030 004 (stat) 027 002 (stat)

JQDisplrsquod trk

046 005 (stat) 034 002 (stat)

JQHigh pT 014 003 (stat) 011 001 (stat)

Total OST 147 010 (stat) 144 004 (stat)

SSKT 35 05 (syst) 40 06 (syst)

Efficiency

Dilution = 1-2bullmistag rate

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

4

UT and constraint from mixing

ΔMd onlyLimit on ΔMs ΔMs ΔMd

From lattice

bull Ratio equiv ξ2 is better

calculated than single factors

bull ξ = 1210 + 0047-0035

(MOkamoto hep-lat0510113)

clubs Measuring ΔMs ΔMd

returns Vts Vtd with ~4 error from theory

ss

dd

Bf

Bf2

2

UP TO WINTER lsquo06bullΔMs ge 166 ps-1 (LEP+SLD+Tevatron I and II)

bullExpected value (UT fit utfitroma1infnit) ΔMs (SM) = 215 plusmn 26 ps -1

ΔMs in [167 269] 95 CLclubs LARGER ΔMs could indicate NP contribrsquos

5

Final stateReconstruct final states from both Semileptonic (high statistics but missing kinematics) and Hadronic (fully reconstructed best ct resolution)

Lifetime measurement Hadronic decay length measured with better resolution than Semileptonic

Flavour tagging Tag the flavour of the mixing B candidate using both

correlation with fragmentation tracks AND flavour of other b (incoherent b-b production)

Want to measurehellipso how

6

Amplitude ScanIntroduce ldquoAmplituderdquo in Likelihood

tMDAeL ttsig cos1

1

Fit A for fixed ΔM

A consistent with1 if mixing detected at a given ΔM

0 if no mixing at a given ΔM

Limit where A+1645σA = 1Sensitivity 1645σA = 1

Example of amplitude scanWorld Average Fall lsquo05

7

BS

Se

DS tsM

A

2

)(22

21

Measurement significanceThe expression of the statistical Significance of a mixing measurement is given by

Signal

(b-flavour at decay tagged)

Fraction of S withinfo also on flavour at creation

Experimental time resolutionexponentially dilutes a measurement

Trigger-challengeto collect Ssuppressing B

Significance exponentially reduced at higher ΔMs hellip

hellip|Vts| gtgt |Vtd| Ms ~40Md

8

Final states selection and yields

9

Hadronic signalsL = 1 fb-1

N(Bs) asymp 3600

)(

)(00

0

ss

ssss

DB

DDDB

ldquoSatellitesrdquo

(Not used in this analysis)

Bs0rarr Ds

- (3)π+ (Ds

- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π

1570 plusmn 43

Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32

Bs rarr Ds π Ds rarr 3π 612 plusmn 37

Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37

Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26

bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with

bull d0 gt 120 μm (τ(B)asymp15ps)

bullPt gt 55 GeVc

10

Semileptonic signals

Bs0rarr Ds

-() ℓ+ν X (Ds

- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)

bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates

11

Lifetime measurement

12

Hadronic Lifetime Results

Modecτ [μm]

(stat only)

B0D- + 4911 plusmn 51

B-D0 - 4521 plusmn 51

BsDs() π 461 plusmn 12

World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps

bullDetailed simulation to correct for trigger bias

on the selection of the B decay lengthbullSyst on trigger efficiency negligible

for mixing measurements

Excellent agreement

13

Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2

2

)( t

t

M

eD

2

20

p

ct pctct

Vertex resolution(constant)

Momentum resolution

(~ct)

bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies

bullCalibrate by fitting for lifetime of B0-like decays

osc period at Ms = 18 ps-1

Hadronic-like

Semileptonic-likeltσppgt asymp15

CDF II

14

Flavour tagging

15

Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently

εD2 Hadronic ()εD2 Semileptonic

()

Muon 048 006 (stat) 062 003 (stat)

Electron 009 003 (stat) 010 001 (stat)

JQSecVtx 030 004 (stat) 027 002 (stat)

JQDisplrsquod trk

046 005 (stat) 034 002 (stat)

JQHigh pT 014 003 (stat) 011 001 (stat)

Total OST 147 010 (stat) 144 004 (stat)

SSKT 35 05 (syst) 40 06 (syst)

Efficiency

Dilution = 1-2bullmistag rate

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

5

Final stateReconstruct final states from both Semileptonic (high statistics but missing kinematics) and Hadronic (fully reconstructed best ct resolution)

Lifetime measurement Hadronic decay length measured with better resolution than Semileptonic

Flavour tagging Tag the flavour of the mixing B candidate using both

correlation with fragmentation tracks AND flavour of other b (incoherent b-b production)

Want to measurehellipso how

6

Amplitude ScanIntroduce ldquoAmplituderdquo in Likelihood

tMDAeL ttsig cos1

1

Fit A for fixed ΔM

A consistent with1 if mixing detected at a given ΔM

0 if no mixing at a given ΔM

Limit where A+1645σA = 1Sensitivity 1645σA = 1

Example of amplitude scanWorld Average Fall lsquo05

7

BS

Se

DS tsM

A

2

)(22

21

Measurement significanceThe expression of the statistical Significance of a mixing measurement is given by

Signal

(b-flavour at decay tagged)

Fraction of S withinfo also on flavour at creation

Experimental time resolutionexponentially dilutes a measurement

Trigger-challengeto collect Ssuppressing B

Significance exponentially reduced at higher ΔMs hellip

hellip|Vts| gtgt |Vtd| Ms ~40Md

8

Final states selection and yields

9

Hadronic signalsL = 1 fb-1

N(Bs) asymp 3600

)(

)(00

0

ss

ssss

DB

DDDB

ldquoSatellitesrdquo

(Not used in this analysis)

Bs0rarr Ds

- (3)π+ (Ds

- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π

1570 plusmn 43

Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32

Bs rarr Ds π Ds rarr 3π 612 plusmn 37

Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37

Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26

bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with

bull d0 gt 120 μm (τ(B)asymp15ps)

bullPt gt 55 GeVc

10

Semileptonic signals

Bs0rarr Ds

-() ℓ+ν X (Ds

- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)

bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates

11

Lifetime measurement

12

Hadronic Lifetime Results

Modecτ [μm]

(stat only)

B0D- + 4911 plusmn 51

B-D0 - 4521 plusmn 51

BsDs() π 461 plusmn 12

World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps

bullDetailed simulation to correct for trigger bias

on the selection of the B decay lengthbullSyst on trigger efficiency negligible

for mixing measurements

Excellent agreement

13

Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2

2

)( t

t

M

eD

2

20

p

ct pctct

Vertex resolution(constant)

Momentum resolution

(~ct)

bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies

bullCalibrate by fitting for lifetime of B0-like decays

osc period at Ms = 18 ps-1

Hadronic-like

Semileptonic-likeltσppgt asymp15

CDF II

14

Flavour tagging

15

Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently

εD2 Hadronic ()εD2 Semileptonic

()

Muon 048 006 (stat) 062 003 (stat)

Electron 009 003 (stat) 010 001 (stat)

JQSecVtx 030 004 (stat) 027 002 (stat)

JQDisplrsquod trk

046 005 (stat) 034 002 (stat)

JQHigh pT 014 003 (stat) 011 001 (stat)

Total OST 147 010 (stat) 144 004 (stat)

SSKT 35 05 (syst) 40 06 (syst)

Efficiency

Dilution = 1-2bullmistag rate

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

6

Amplitude ScanIntroduce ldquoAmplituderdquo in Likelihood

tMDAeL ttsig cos1

1

Fit A for fixed ΔM

A consistent with1 if mixing detected at a given ΔM

0 if no mixing at a given ΔM

Limit where A+1645σA = 1Sensitivity 1645σA = 1

Example of amplitude scanWorld Average Fall lsquo05

7

BS

Se

DS tsM

A

2

)(22

21

Measurement significanceThe expression of the statistical Significance of a mixing measurement is given by

Signal

(b-flavour at decay tagged)

Fraction of S withinfo also on flavour at creation

Experimental time resolutionexponentially dilutes a measurement

Trigger-challengeto collect Ssuppressing B

Significance exponentially reduced at higher ΔMs hellip

hellip|Vts| gtgt |Vtd| Ms ~40Md

8

Final states selection and yields

9

Hadronic signalsL = 1 fb-1

N(Bs) asymp 3600

)(

)(00

0

ss

ssss

DB

DDDB

ldquoSatellitesrdquo

(Not used in this analysis)

Bs0rarr Ds

- (3)π+ (Ds

- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π

1570 plusmn 43

Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32

Bs rarr Ds π Ds rarr 3π 612 plusmn 37

Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37

Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26

bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with

bull d0 gt 120 μm (τ(B)asymp15ps)

bullPt gt 55 GeVc

10

Semileptonic signals

Bs0rarr Ds

-() ℓ+ν X (Ds

- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)

bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates

11

Lifetime measurement

12

Hadronic Lifetime Results

Modecτ [μm]

(stat only)

B0D- + 4911 plusmn 51

B-D0 - 4521 plusmn 51

BsDs() π 461 plusmn 12

World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps

bullDetailed simulation to correct for trigger bias

on the selection of the B decay lengthbullSyst on trigger efficiency negligible

for mixing measurements

Excellent agreement

13

Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2

2

)( t

t

M

eD

2

20

p

ct pctct

Vertex resolution(constant)

Momentum resolution

(~ct)

bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies

bullCalibrate by fitting for lifetime of B0-like decays

osc period at Ms = 18 ps-1

Hadronic-like

Semileptonic-likeltσppgt asymp15

CDF II

14

Flavour tagging

15

Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently

εD2 Hadronic ()εD2 Semileptonic

()

Muon 048 006 (stat) 062 003 (stat)

Electron 009 003 (stat) 010 001 (stat)

JQSecVtx 030 004 (stat) 027 002 (stat)

JQDisplrsquod trk

046 005 (stat) 034 002 (stat)

JQHigh pT 014 003 (stat) 011 001 (stat)

Total OST 147 010 (stat) 144 004 (stat)

SSKT 35 05 (syst) 40 06 (syst)

Efficiency

Dilution = 1-2bullmistag rate

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

7

BS

Se

DS tsM

A

2

)(22

21

Measurement significanceThe expression of the statistical Significance of a mixing measurement is given by

Signal

(b-flavour at decay tagged)

Fraction of S withinfo also on flavour at creation

Experimental time resolutionexponentially dilutes a measurement

Trigger-challengeto collect Ssuppressing B

Significance exponentially reduced at higher ΔMs hellip

hellip|Vts| gtgt |Vtd| Ms ~40Md

8

Final states selection and yields

9

Hadronic signalsL = 1 fb-1

N(Bs) asymp 3600

)(

)(00

0

ss

ssss

DB

DDDB

ldquoSatellitesrdquo

(Not used in this analysis)

Bs0rarr Ds

- (3)π+ (Ds

- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π

1570 plusmn 43

Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32

Bs rarr Ds π Ds rarr 3π 612 plusmn 37

Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37

Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26

bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with

bull d0 gt 120 μm (τ(B)asymp15ps)

bullPt gt 55 GeVc

10

Semileptonic signals

Bs0rarr Ds

-() ℓ+ν X (Ds

- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)

bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates

11

Lifetime measurement

12

Hadronic Lifetime Results

Modecτ [μm]

(stat only)

B0D- + 4911 plusmn 51

B-D0 - 4521 plusmn 51

BsDs() π 461 plusmn 12

World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps

bullDetailed simulation to correct for trigger bias

on the selection of the B decay lengthbullSyst on trigger efficiency negligible

for mixing measurements

Excellent agreement

13

Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2

2

)( t

t

M

eD

2

20

p

ct pctct

Vertex resolution(constant)

Momentum resolution

(~ct)

bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies

bullCalibrate by fitting for lifetime of B0-like decays

osc period at Ms = 18 ps-1

Hadronic-like

Semileptonic-likeltσppgt asymp15

CDF II

14

Flavour tagging

15

Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently

εD2 Hadronic ()εD2 Semileptonic

()

Muon 048 006 (stat) 062 003 (stat)

Electron 009 003 (stat) 010 001 (stat)

JQSecVtx 030 004 (stat) 027 002 (stat)

JQDisplrsquod trk

046 005 (stat) 034 002 (stat)

JQHigh pT 014 003 (stat) 011 001 (stat)

Total OST 147 010 (stat) 144 004 (stat)

SSKT 35 05 (syst) 40 06 (syst)

Efficiency

Dilution = 1-2bullmistag rate

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

8

Final states selection and yields

9

Hadronic signalsL = 1 fb-1

N(Bs) asymp 3600

)(

)(00

0

ss

ssss

DB

DDDB

ldquoSatellitesrdquo

(Not used in this analysis)

Bs0rarr Ds

- (3)π+ (Ds

- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π

1570 plusmn 43

Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32

Bs rarr Ds π Ds rarr 3π 612 plusmn 37

Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37

Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26

bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with

bull d0 gt 120 μm (τ(B)asymp15ps)

bullPt gt 55 GeVc

10

Semileptonic signals

Bs0rarr Ds

-() ℓ+ν X (Ds

- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)

bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates

11

Lifetime measurement

12

Hadronic Lifetime Results

Modecτ [μm]

(stat only)

B0D- + 4911 plusmn 51

B-D0 - 4521 plusmn 51

BsDs() π 461 plusmn 12

World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps

bullDetailed simulation to correct for trigger bias

on the selection of the B decay lengthbullSyst on trigger efficiency negligible

for mixing measurements

Excellent agreement

13

Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2

2

)( t

t

M

eD

2

20

p

ct pctct

Vertex resolution(constant)

Momentum resolution

(~ct)

bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies

bullCalibrate by fitting for lifetime of B0-like decays

osc period at Ms = 18 ps-1

Hadronic-like

Semileptonic-likeltσppgt asymp15

CDF II

14

Flavour tagging

15

Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently

εD2 Hadronic ()εD2 Semileptonic

()

Muon 048 006 (stat) 062 003 (stat)

Electron 009 003 (stat) 010 001 (stat)

JQSecVtx 030 004 (stat) 027 002 (stat)

JQDisplrsquod trk

046 005 (stat) 034 002 (stat)

JQHigh pT 014 003 (stat) 011 001 (stat)

Total OST 147 010 (stat) 144 004 (stat)

SSKT 35 05 (syst) 40 06 (syst)

Efficiency

Dilution = 1-2bullmistag rate

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

9

Hadronic signalsL = 1 fb-1

N(Bs) asymp 3600

)(

)(00

0

ss

ssss

DB

DDDB

ldquoSatellitesrdquo

(Not used in this analysis)

Bs0rarr Ds

- (3)π+ (Ds

- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π

1570 plusmn 43

Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32

Bs rarr Ds π Ds rarr 3π 612 plusmn 37

Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37

Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26

bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with

bull d0 gt 120 μm (τ(B)asymp15ps)

bullPt gt 55 GeVc

10

Semileptonic signals

Bs0rarr Ds

-() ℓ+ν X (Ds

- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)

bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates

11

Lifetime measurement

12

Hadronic Lifetime Results

Modecτ [μm]

(stat only)

B0D- + 4911 plusmn 51

B-D0 - 4521 plusmn 51

BsDs() π 461 plusmn 12

World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps

bullDetailed simulation to correct for trigger bias

on the selection of the B decay lengthbullSyst on trigger efficiency negligible

for mixing measurements

Excellent agreement

13

Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2

2

)( t

t

M

eD

2

20

p

ct pctct

Vertex resolution(constant)

Momentum resolution

(~ct)

bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies

bullCalibrate by fitting for lifetime of B0-like decays

osc period at Ms = 18 ps-1

Hadronic-like

Semileptonic-likeltσppgt asymp15

CDF II

14

Flavour tagging

15

Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently

εD2 Hadronic ()εD2 Semileptonic

()

Muon 048 006 (stat) 062 003 (stat)

Electron 009 003 (stat) 010 001 (stat)

JQSecVtx 030 004 (stat) 027 002 (stat)

JQDisplrsquod trk

046 005 (stat) 034 002 (stat)

JQHigh pT 014 003 (stat) 011 001 (stat)

Total OST 147 010 (stat) 144 004 (stat)

SSKT 35 05 (syst) 40 06 (syst)

Efficiency

Dilution = 1-2bullmistag rate

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

10

Semileptonic signals

Bs0rarr Ds

-() ℓ+ν X (Ds

- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)

bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates

11

Lifetime measurement

12

Hadronic Lifetime Results

Modecτ [μm]

(stat only)

B0D- + 4911 plusmn 51

B-D0 - 4521 plusmn 51

BsDs() π 461 plusmn 12

World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps

bullDetailed simulation to correct for trigger bias

on the selection of the B decay lengthbullSyst on trigger efficiency negligible

for mixing measurements

Excellent agreement

13

Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2

2

)( t

t

M

eD

2

20

p

ct pctct

Vertex resolution(constant)

Momentum resolution

(~ct)

bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies

bullCalibrate by fitting for lifetime of B0-like decays

osc period at Ms = 18 ps-1

Hadronic-like

Semileptonic-likeltσppgt asymp15

CDF II

14

Flavour tagging

15

Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently

εD2 Hadronic ()εD2 Semileptonic

()

Muon 048 006 (stat) 062 003 (stat)

Electron 009 003 (stat) 010 001 (stat)

JQSecVtx 030 004 (stat) 027 002 (stat)

JQDisplrsquod trk

046 005 (stat) 034 002 (stat)

JQHigh pT 014 003 (stat) 011 001 (stat)

Total OST 147 010 (stat) 144 004 (stat)

SSKT 35 05 (syst) 40 06 (syst)

Efficiency

Dilution = 1-2bullmistag rate

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

11

Lifetime measurement

12

Hadronic Lifetime Results

Modecτ [μm]

(stat only)

B0D- + 4911 plusmn 51

B-D0 - 4521 plusmn 51

BsDs() π 461 plusmn 12

World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps

bullDetailed simulation to correct for trigger bias

on the selection of the B decay lengthbullSyst on trigger efficiency negligible

for mixing measurements

Excellent agreement

13

Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2

2

)( t

t

M

eD

2

20

p

ct pctct

Vertex resolution(constant)

Momentum resolution

(~ct)

bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies

bullCalibrate by fitting for lifetime of B0-like decays

osc period at Ms = 18 ps-1

Hadronic-like

Semileptonic-likeltσppgt asymp15

CDF II

14

Flavour tagging

15

Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently

εD2 Hadronic ()εD2 Semileptonic

()

Muon 048 006 (stat) 062 003 (stat)

Electron 009 003 (stat) 010 001 (stat)

JQSecVtx 030 004 (stat) 027 002 (stat)

JQDisplrsquod trk

046 005 (stat) 034 002 (stat)

JQHigh pT 014 003 (stat) 011 001 (stat)

Total OST 147 010 (stat) 144 004 (stat)

SSKT 35 05 (syst) 40 06 (syst)

Efficiency

Dilution = 1-2bullmistag rate

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

12

Hadronic Lifetime Results

Modecτ [μm]

(stat only)

B0D- + 4911 plusmn 51

B-D0 - 4521 plusmn 51

BsDs() π 461 plusmn 12

World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps

bullDetailed simulation to correct for trigger bias

on the selection of the B decay lengthbullSyst on trigger efficiency negligible

for mixing measurements

Excellent agreement

13

Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2

2

)( t

t

M

eD

2

20

p

ct pctct

Vertex resolution(constant)

Momentum resolution

(~ct)

bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies

bullCalibrate by fitting for lifetime of B0-like decays

osc period at Ms = 18 ps-1

Hadronic-like

Semileptonic-likeltσppgt asymp15

CDF II

14

Flavour tagging

15

Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently

εD2 Hadronic ()εD2 Semileptonic

()

Muon 048 006 (stat) 062 003 (stat)

Electron 009 003 (stat) 010 001 (stat)

JQSecVtx 030 004 (stat) 027 002 (stat)

JQDisplrsquod trk

046 005 (stat) 034 002 (stat)

JQHigh pT 014 003 (stat) 011 001 (stat)

Total OST 147 010 (stat) 144 004 (stat)

SSKT 35 05 (syst) 40 06 (syst)

Efficiency

Dilution = 1-2bullmistag rate

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

13

Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2

2

)( t

t

M

eD

2

20

p

ct pctct

Vertex resolution(constant)

Momentum resolution

(~ct)

bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies

bullCalibrate by fitting for lifetime of B0-like decays

osc period at Ms = 18 ps-1

Hadronic-like

Semileptonic-likeltσppgt asymp15

CDF II

14

Flavour tagging

15

Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently

εD2 Hadronic ()εD2 Semileptonic

()

Muon 048 006 (stat) 062 003 (stat)

Electron 009 003 (stat) 010 001 (stat)

JQSecVtx 030 004 (stat) 027 002 (stat)

JQDisplrsquod trk

046 005 (stat) 034 002 (stat)

JQHigh pT 014 003 (stat) 011 001 (stat)

Total OST 147 010 (stat) 144 004 (stat)

SSKT 35 05 (syst) 40 06 (syst)

Efficiency

Dilution = 1-2bullmistag rate

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

14

Flavour tagging

15

Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently

εD2 Hadronic ()εD2 Semileptonic

()

Muon 048 006 (stat) 062 003 (stat)

Electron 009 003 (stat) 010 001 (stat)

JQSecVtx 030 004 (stat) 027 002 (stat)

JQDisplrsquod trk

046 005 (stat) 034 002 (stat)

JQHigh pT 014 003 (stat) 011 001 (stat)

Total OST 147 010 (stat) 144 004 (stat)

SSKT 35 05 (syst) 40 06 (syst)

Efficiency

Dilution = 1-2bullmistag rate

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

15

Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently

εD2 Hadronic ()εD2 Semileptonic

()

Muon 048 006 (stat) 062 003 (stat)

Electron 009 003 (stat) 010 001 (stat)

JQSecVtx 030 004 (stat) 027 002 (stat)

JQDisplrsquod trk

046 005 (stat) 034 002 (stat)

JQHigh pT 014 003 (stat) 011 001 (stat)

Total OST 147 010 (stat) 144 004 (stat)

SSKT 35 05 (syst) 40 06 (syst)

Efficiency

Dilution = 1-2bullmistag rate

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

16

Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour

and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum

range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr

cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to

fragmentationThen test predictions on data for other species (B+ and

Bd) and add systematics on agreement accordingly for usage with Bs

Bs

K- K0

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

17

RESULTS

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

18

Amplitude Scan (hadronic+semileptonic)

AA (173 ps-1) = 37

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

19

SensitivityCDF sensitivity compared to WA

CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)

This sensitivity reached withbull1 fb-1

bullAddition of SSKTbullImproved σct fitting model

Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

20

Significance of the peak

From data ndashΔlog(L)MIN = -675

Randomize tags ~50k times on data and

calculatehellipP-value = 02

Significance gt 3σrarr assume that peak IS real mixing signal

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

21

FinallyhellipΔMs

bullContribution of hadronic modes essential due to better

ct resolution at high ΔMs

σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL

bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time

measurement

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

22

From ΔMs information on UT

bullCompatible with SM within 1σ

bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1

from PDG06 and ξ = 1210+ 0047

-0035 hep-lat 0510113)

we infer the value |Vtd||Vts| = 0208 +0001

-0002 (exp) +0008 -0006 (th)

bullConstraint on CBsCBs = Ms

SM+NPMsSM = 101 033

[033204] 95 CL (UTFit utfitroma1infnit)

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002

23

ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT

ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)

hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002