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Page 1: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Dalitz analysesDalitz analyses IntroductionBelle Analysis School

October 1-2 2009

Hi, could you talk b t D lit

Sure...A couple of months ago, somwehere on

about Dalitzat the BAS?

g ,the net....

A couple of weeks ago, somwehere on

Yes...?

WHO did you saythe net.... WHO did you say I should talk about...?

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 1 BAS, KEK, October 2009

Page 2: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Dalitz analysesDalitz analyses IntroductionBelle Analysis School

Boštjan GolobBelle & Belle II

University of Ljubljana Jožef Stefan Institute

October 1-2 2009

University of Ljubljana, Jožef Stefan Institute

1. Introduction2. Kinematics3. Physics4. Parametrization4. Parametrization5. Experimental issues6. Specifics, Outlook

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 2 BAS, KEK, October 2009

Page 3: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

IntroductionHistoryHistory

Richard Henry Dalitz (28 February 1925 – 13 January 2006);Australian physicist;Australian physicist;

@ Cornell introduced “phase space plotsphase space plots”, i.e. Dalitz technique (as called today), e a t tec que (as ca ed today),to study 3π “tau” (kaon) decays;

On the analysis of τ meson data and the nature of the τ mesonOn the analysis of τ-meson data and the nature of the τ-meson Author: R. H. Dalitz a

Affiliation: a Department of Mathematical Physics, University of Birmingham, y gDOI: 10.1080/14786441008520365 Published in: Philosophical Magazine Series 7, Volume 44, Issue 357 October 1953 , pages 1068 - 1080

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 3 BAS, KEK, October 2009

Page 4: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Kinematicsn-body decayJ.D. Jackson, D.R. Tovey, Kinematics, in RPP

( )Φ=Γ nn

d

ppPdM

d

3

12

4

),;(22π

KM

∏∑==

−=Φni i

i

niinn E

pdpPppPd,1

3

3

,1

41 2)2(

)(),;(π

δK LISP:Lorent InvariantPhase Sace

independent variables: 4-vectors: 4 n +

ti l 4 3 7n=3 2n=3 2

conservation laws: 4 = 3 n - 7final state masses: n -arbitrary rotations: 3

n=4 5n=5 8

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 4 BAS, KEK, October 2009

Page 5: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Kinematics3 body decay

J.D. Jackson, D.R. Tovey, Kinematics, in RPP,

3-body decay

take two inv. masses asindependent variables decaying particle:independent variables

213

212

233 32

1)2(

1 dmdmM

d M=Γ

decaying particle:scalar or averagingover spin states33 32)2( Mπ p

mij: inv. mass of part. i,j.2

322

21

2223

213

212 constmmmMmmm =+++=++

211M

dΓ332

13212 32)2(

MMdmdm π

= standard form of Dalitz plot

if |M|2 const ⇒ dΓ/dm 2dm 2 const

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 5 BAS, KEK, October 2009

if |M|2 const. ⇒ dΓ/dm122dm13

2 const.

Page 6: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Kinematics Belle, PRL 99, 131803 (2007)

)

3-body decay

example: D0 → Ksπ -π+ m2 (

KSπ

+ )

cos2

θ

non-uniformity of Dalitz plot ⇒contribution of intermediate states

Ki ti li itKinematic limitsD0 → π+K*- m2(KSπ-)J.D. Jackson, D.R. Tovey, Kinematics, in RPP

θ23*=π

( ) ( ) 222 2mmm +θ23*=0

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 6 BAS, KEK, October 2009

( ) ( )( ) ( )min

223max

223

23max23min23*23

2cos

mmmmm

−−+

=θ 34

Page 7: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

KinematicsM1

3-body decay

various intermediate states Mk

contributing to same final state ⇒ interfereinterferenncece

Mn

|M|2 is not incoherent sum, (|M|2 ≠ |M1|2 + |M2|2 + ... ) ,

n

but a coherent sum, ( |M|2 = |M1+ M2 + ...|2 )

example: pp → 3π0

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 7 BAS, KEK, October 2009

Page 8: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

PhysicsCleo-c, arXiv:0903.1301

New states and propertiesof known states

,

Dalitz analysis usually not needed for narrow, non-overlapping

K*0

resonances(negligible interference)example: Ds → K+K-π+

(but interf. φπ/KKπ, φπ/f0πimportant in precise Br(Ds → φπ)determination)

φ

determination)

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 8 BAS, KEK, October 2009

another example: 37

Page 9: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

PhysicsB → KZ+(4430)

Belle, PRD 80, 031104(R) (2009)

New states and propertiesof known states

KZ (4430)

In most cases intermediate states strongly interfere

Z+(4430)example: B → Kπ+ψ’

by fitting fitting DalitzDalitz distributiondistributionobtain evidence of newobtain evidence of new states, measure properties(mass width spin)

B → K*(892)ψ’

B → K0*(1430)ψ’

(mass, width, spin)

projection of Dalitz disribution and fit to

24

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 9 BAS, KEK, October 2009

disribution and fit to M(π+ψ’)

Page 10: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Physics20 )( tAyixqAefDd t +

+=→Γ −

D0 Mixing and CPV

x, y: mixing parameters;

2tA

pAe

dt ff +=

due to mixing, D0 → D0 → fx, y << 1

ΓΓ−Γ

=Γ−

==2

;;' 2121 ymmxttτ

t-dependent pDalitz analyses

different types of interm states;different types of interm. states;example: D0 → π+π- KS

CF: D0 → K*-π+

DCS: D0 → K*+π-

CP: D0 → ρ0 KS

if f = f ⇒ populate same Dalitz plot; l ti h d t i dl ti h d t i d

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 10 BAS, KEK, October 2009

relative phases determined relative phases determined 28

Page 11: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Physics Belle, PRL 99, 131803 (2007)

t dependentt

t-dependent Dalitz analyses

t-dependence:t-dependence:regions of Dalitz plane →specific t dependence F(x, y);

time evolution of Dalitz distribution⇒⇒ x, y x, y

[ ]titi

S

eemm

tDKtmm

21)(1

)(),,(

22

022

λλ

ππ

−−

−++−

++=

=≡

A

MD0→f

28

[ ]

[ ]titi eemmpq

eemm

21),(21

),(2

22 λλ −−+−

+−

−+

++=

A

AD0→f

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 11 BAS, KEK, October 2009

p2λ1,2=F(x,y); m±

2 = m2(KSπ±),

Page 12: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

PhysicsBelle, arXiv:0803.3375

φ measurementφ3 measurement

B- →K- D0(→ f)B- →K- D0(→ f)B →K D0(→ f)interference ⇒ |M|2 = F(φ3) f= π+π- KS

),(),())(( 22220)(

+±±

−±± +=→→ mmAremmAfDKB ii

mmδϕM(

A: D0 decays; r: ratio of two B amplitudes; δ: strong phase diff. of two B amplitudes

A from fit to Dalitz fit to Dalitz distribution of D0 decays;

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 12 BAS, KEK, October 2009

r, φ3, δ (in principle) from fit to Dalitz fit to Dalitz distribution of B± decays30

Page 13: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

sin 2φ eff in b → sqq

Physics SM:

sin 2φ1eff in b → sqq

NP contrib. ⇒ sin 2φ1eff ≠ sin 2φ1

effVtbVts* : no weak phase

quasi twoquasi two--bodybody, B → ρ0(770)KS, f0(980)KSBelle, PRD76, 091103(R) (2007)BaBar, PRL99, 161802 (2007)B B PRL98 051803 (2007)

B→BaBar, PRL98, 051803 (2007)

Vtd* 2: (mixing): sin2φ1

NP:

[ ]tmqStmqAetP CPCP

t

∆∆−∆∆+=∆∆−

sincos14

)(/||

τ

τ

interf. between various states and non-resonant contrib. ⇒ Dalitz analysis

sη’

B0 g

g~b s

+(δ 23

dRR)b

~R

s~

NP:

d d

s

s Ks

B0 gs~R

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 13 BAS, KEK, October 2009

∆S=sin2φ1eff -sin2φ1

Page 14: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Physicssin 2φ eff in b → sqqsin 2φ1

eff in b → sqq

[ ]tmqStmqAetP CPCP

t

∆∆−∆∆+=∆∆−

sincos14

)(/||

τ

τ

),( 22mmmAA ±=

each point in Dalitz space has a specific time evolution depending onevolution, depending on |A|2-|A|2 (direct CPV)(direct CPV)and ℑ(AA*) (indirect CPVindirect CPV corresponding to

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 14 BAS, KEK, October 2009

ℑ(AA ) (indirect CPVindirect CPV, corresponding to specific two-body contribution sin 2sin 2φφ11

effeff (i)(i))

Page 15: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Parametrizationdescription of Dalitz distributiondescription of Dalitz distribution

a matter of statistics102 pp → 3π0 events10 pp → 3π events

Adopted from K. Peters, talk at Charm 2006, Beijing

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 15 BAS, KEK, October 2009

Page 16: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Parametrizationdescription of Dalitz distributiondescription of Dalitz distribution

a matter of statistics103 pp → 3π0 events10 pp → 3π events

Adopted from K. Peters, talk at Charm 2006, Beijing

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 16 BAS, KEK, October 2009

Page 17: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Parametrizationdescription of Dalitz distributiondescription of Dalitz distribution

a matter of statistics104 pp → 3π0 events104 pp → 3π0 events

Adopted from K. Peters, talk at Charm 2006, Beijing

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 17 BAS, KEK, October 2009

Page 18: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Parametrizationdescription of Dalitz distributiondescription of Dalitz distribution

a matter of statistics105 pp → 3π0 events

larger stat. ⇒ larger sensitivity to model details

Breit-Wigner resonances

10 pp → 3π events

Breit Wigner resonancessimple consideration of spin 0 elastic scatteringleads to the Breit-Wigner amplitude for a b → r → a b

Adopted from K. Peters, talk at Charm 2006, Beijing

// 2

4/)(4/

2/2/

22

22

Γ+−Γ

=Γ−−

Γ=

EmT

iEmT

rr

|T|2 |T|2

mr=1.0Γ=0.3

mr=0.5Γ=0.2

| |

Γ

mR

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 18 BAS, KEK, October 2009

E E

Page 19: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

ParametrizationBreit Wigner resonances

|T1+ T2 |2

Breit-Wigner resonances

several intermediate statesb ba b → r1 → a b

r2model amplitude as sum of BW amplitudes;

E

sum of BW’s amplitudes; - the approach violates unitarity for wide overlapping resonances;

- the BW shape is distorted close

(“isobar model”)most commonly used most commonly used to model Dalitz distributionsthe BW shape is distorted close

to the thresholds;

parametrization of Dalitz distribution is

distributions

22

D0, B0 → ABCpa model, phenomenological object;

it should provide adequate description adequate description ∑ Φ

=

rACAB

BWr

ir

ACAB

mmAea

mmr ),(

),(22

22A

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 19 BAS, KEK, October 2009

of dataof data; caution needed in interpretation

r

Page 20: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

ParametrizationBW resonancesBW resonances

parametrization usually follows Cleo PRD63 092001 (2001) J 0Cleo, PRD63, 092001 (2001) JA,B,C=0

resonance spin

J=0

J=1

J=2

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 20 BAS, KEK, October 2009

Page 21: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

ParametrizationBW resonancesBW resonances

parametrization usually follows Cleo PRD63 092001 (2001)Cleo, PRD63, 092001 (2001)

JA,B,C=0

mass dependent width;pAB: momentum of A/B in AB rest frame;pr : momentum of A/B in rest frame of r;

Fi

Ji=0

pr ;(note: MAB may not equal Mr)

i

Ji=1 form factors (Blatt-Weisskopf)

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 21 BAS, KEK, October 2009

Ji=2 R: phenomenological factor(0 GeV-1 – 10 GeV-1 for D0, 0 GeV-1 – 3 GeV-1 for r)

Page 22: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

ParametrizationBW resonancesBW resonances

Refinements - FlattFlattéé parametrizationFlattFlattéé parametrization

if 2nd channel for r decays opens close to mr;example f0(980) → ππ, +−−

=0

220

0 )(1

KKKKfff ggimmm

Aρρ ππππππ

S.M. Flatté, PLB63, 224 (1976)

p 0( ) ,KK threshold close to mf0

- parametrization of nonnon resonantresonant contribution

⎟⎟⎠

⎞⎜⎜⎝

⎛ −−⎟

⎟⎠

⎞⎜⎜⎝

⎛ +−= 2

2

2

2 )(1

)(1

ij

ji

ij

jiij

ff

mmm

mmm

ρ

nonnon--resonantresonant contribution in D0 decays usually a constantterm; in B0 charmless decays phase

gij: couplings r/ij(note: mismatch in several papers on Flatté parameters of f0(980) and a (980); contact A Zupanc Zhao Li orin B charmless decays phase

space larger, some variations of ANR; example B0 →KSπ+π- ANR ∝ exp(-αmij

2) Belle, PRD79, 072004 (2009)

a0(980); contact A. Zupanc, Zhao Li orB.G.)

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 22 BAS, KEK, October 2009

p S NR p( ij )B → Dππ ANR = const.

, , ( )

Belle, PRD76, 012006 (2007)

Page 23: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

ParametrizationK matrix

E.P. Wigner, Phys. Rev. 70, 15 (1946);S.U. Chung et al., Ann. Phys. 4, 404 (1995)

K-matrix

- sum of BW’s violates unitaritybroad S wave ππ Kπ states are

ρρ TiIS

iSfS fi

+=

=2/12/12

- broad S-wave ππ, Kπ states are not simple BW’s

scattering operator Sρ

ρ

iTKKiKIT

+=

−=−−

11

1)(

scattering operator Stransition operator TK matrix

++ =⇔= KKISS

iijij = ρδρoriginally developed for description of scattering

can be adopted to production processproduction process, smm ii

i

221 )(1 +

−=ρ

e.g. D, B decays, using scattering data scattering data

kfkf KiKIT 1)( −−= ρ D

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 23 BAS, KEK, October 2009

I.J.R. Aitchison, Nucl. Phys. A189, 514 (1972); kfkf PiKIF 1)( −−= ρ P (I-iKρ)-1

Page 24: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

ParametrizationK matrix PiKIF 1)( −−= ρK-matrix

assume we are parametrizing a 2 body

Drescattering of k→ ππ

production of k K

kk PiKIF ,)(= ππππ ρ

parametrizing a 2-body intermediate state of a 3-body final state(example: ππ in KSπ+π-):

P (I-iKρ)-1of k→ ππ of k KS

k=ππ, KK, ηη, ...

(example: ππ in KSπ π ):Belle, PRL99, 131803 (2007)BaBar, hep-ex/0507101 scatt

scattprod

kr r

rkr

k sssf

smgP

0

0,2

1−−

+−

= ∑ ππβ

s=m2ππ

scattrr 1 ⎪⎫⎪⎧

resonances - poles;(may not coincide withphysical states)

slow-varying part;

factorkinemsssf

smgg

K scatt

scattscatt

ijr r

rj

ri

ij .1

0

02 ⋅

⎪⎭

⎪⎬⎫

⎪⎩

⎪⎨⎧

−−

+−

= ∑

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 24 BAS, KEK, October 2009

gir, mr, fijscatt, s0

scatt : from compilation of ππ scattering datascattering data

Page 25: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

ParametrizationK matrix gg ρρ D. Asner, Dalitz plot analysis K-matrix

for single channel (e g ππ)

)()1(2

1

2

gKiKT

smggK

ρππ

ρ

ππππ

==

−=

formalism, in RPP

(e.g. ππ) and single pole(e.g. ρ0): )(

)()1( 22

smg

gismKiKT

ρρρππ

ρππρ

Γ=

−−=−=

KK--matrix = single BWmatrix = single BW

for multiple channels )(

)(2 simsm

smT

ρρρ

ρρ

Γ−−Γ

=

pand/or multiple poles:

KK--matrix matrix ≠≠ multiple BW multiple BW

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 25 BAS, KEK, October 2009

S. Malvezzi, talk at Charm07, Cornell

Page 26: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Experimental issues

Inv. mass resolutiontypically σ << Γ;e g B → Dππ: σ ~3 MeV;e.g. B → Dππ: σππ 3 MeV;non-negligible for φ(K+K-), ω(π+π-)→ ABW⊗G(σ) numerically (or included in syst.)

also non-negligible at Dalitz boundaries→ mass constraint fit mass constraint fit of ABC to D0, B0;also same Dalitz region signal/sideband (background description)

EfficiencyABW(mAB

2,mAC2) → ABW (mAB

2,MAC2) • ε (mAB

2,mAC2);

ε (mAB2,mAC

2) from MC generated uniformly over phase space;parametrization (factorize mAB

2,mAC2 dependence)

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 26 BAS, KEK, October 2009

Page 27: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Experimental issues

BackgroundD0, B0 mass sidebands 2222

,

22,

22 //

ACAB

side

ACABside

MCbkg

ACABsig

MCbkg

ACAB

bkg

dmdmdN

dmdmdNdmdmdN

dmdmdN

⋅=

Fitmany issues (talk by E. White)(talk by E. White);- unbinned sometimes binned;

Dalitz model testunbinned, sometimes binned;

- fit quality bin Dalitz plot, χ2;model appropriateness

test

pp p(hypothesis testing)→ compare lnL for various models;significances of ind. contributions

Dalitz + decay tfit test(talk by B. (talk by B. YabsleyYabsley););

- biastest using MC with generated Dalitz model,

l D0 K +

fit test

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 27 BAS, KEK, October 2009

example D0 →KSπ+π- Belle, PRL99, 131803 (2007)Belle Note 9799

Page 28: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Experimental issuesFit

Belle, PRD79, 072004 (2009)

Fit- multiple solutions,

example B0 →KSπ+π-

test for multiple solutions by performing numerous fits with varying starting values of solution 1 solution 2y g gparameters;

toy MC to checks if some solutions due to stat fluctuations;

K0*(1430)+π- fit fraction:~ 65% ~ 17%

due to stat. fluctuations;

- individual contribution∑ Φ= 2222 ),(),(

rACAB

BWr

irACAB mmAeamm rA

- individual contribution → fit fraction, fi

Σfi ≠ 100%

∫ ∑

∫ Φ

= 2

22222 ),( ACABACABBWi

ii

i

r

dmdmmmAeaf

i

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 28 BAS, KEK, October 2009

∫ ∑ Φ 2222 ),( ACABr

ACABBWr

ir dmdmmmAea r

Page 29: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Experimental issuesFitFit

- systematic uncertainty due to Dalitz model

variation of resonance parameters (width mass );variation of resonance parameters (width, mass, ...);variation of form factors, dependence of width on mass; inclusion/exclusion of intermediate states with low signif.; difference isobar / K-matrix model;;possible biases (MC)

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 29 BAS, KEK, October 2009

Page 30: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Specifics, outlookZ+(4430)

Belle, PRD 80, 031104(R) (2009)

Z (4430)New states and propertiesof known states

Larger statistics important for significance;

ibilit t di ti i hpossibility to distinguish JZ=1 and JZ=0

(hypothesis testing)(hypothesis testing)

Outlook:Outlook:

more surprises

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 30 BAS, KEK, October 2009

BaBar, PRD 79, 112001 (2009)

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Specifics, outlookD0 Mi i d CPV

Belle, PRL 99, 131803 (2007), 540fb-1

D0 Mixing and CPVK*X(1400)+

)%290800( 130±±x

K*(892)+

)%24.033.0(

)%29.080.0(

14.010.0

16.013.0

±±=

±±=

y

x

(89 )

K*(892)- ρ/ωpq 09.010.0

29.030.086.0/ ±±=

rad)09.030.028.024.0( ±±−=ϕ

relative sign of x, y; K-matrix used for systematics

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 31 BAS, KEK, October 2009

1038

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Specifics, outlookBelle PRL 96 151801 (2006)D0 Mixing and CPV

direct determination of x, y0

∑ +−Φ

+− =r

BWr

ir mmAeamm r ),(),( 2222A

Belle, PRL 96, 151801 (2006)

instead of x’, y’ as in D0 →K+π-

(rotated for unknown δ between CF and DCS)

r

a1=1, Φ1=0relative phases determined from the fit to Dalitz distribution

2⎤⎡

Outlook:

fit to Dalitz distribution

[ ] 2

2

2 08030.0⎥⎤

⎢⎡

[ ] 2

0

2 06.0/

30.0 radrad+

⎥⎥⎦

⎢⎢⎣

⎡=

LLϕσ need to reduce Dalitzmodel systematics;

[ ] 2

0

2|/| 08.0

/30.0

+⎥⎥⎦⎢

⎢⎣

=LLpqσ other modes: KSKK, πππ0,...

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 32 BAS, KEK, October 2009

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Specifics, outlookφ3 measurement

B- →K- D0(→ f) ))(( 0)(−

±± =→→ fDKBM(

Belle, arXiv:0803.3375

( )B- →K- D0(→ f)interference ⇒ |M|2 = F(φ3) f= π+π- KS

),(),(

))((2222 3±

+±± +

→→

mmAremmA

fDKBii

mmδϕ

M(

S

use x±, y± instead of r, φ3, δ;→ more free parameters; )sin(

)cos(

3

3

δφδφ

+±=+±=

±±

±±

ryrx

lower bias, simple distributions

φ3=76o (+12o -13o) ± 4o ± 9o

Outlook:model independent determination;

22222

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 33 BAS, KEK, October 2009from Cleo-c

)),(),((|| 22222±± −= mmmm DD mm δδFM

12

Page 34: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Specifics, outlooksin 2φ eff in b → sqq BaBar PRD 79 112001 (2009)

example B →J/ψKπ

Belle, PRD79, 072004 (2009)

sin 2φ1eff in b → sqq

change of variables →rectangular Dalitz plot

22

BaBar, PRD 79, 112001 (2009)

22

122arccos1'

''det θ

πππ ⎞⎜⎜⎛

−−

=

→±

mmm

ddmJdmdm m

01'

2

θθ

π π

=

⎠⎜⎝ −− mmm KsB

K

π-

θ

K*0

π

B

KSθ0

a oid concentration of e ents

π+

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 34 BAS, KEK, October 2009

avoid concentration of events at Dalitz boundaries 39

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Specifics, outlooksin 2φ eff in b → sqq

Belle, PRD79, 072004 (2009)

sin 2φ1eff in b → sqq

φ1eff(f0)=(12.7 ±6.9

6.5±2.8±3.3)o

Outlook:

⎨⎧≤∆ sKfS 03.0)( 0

⎩⎨⎧≤∆

s

sK

fS ϕσ 05.003.0)( 0

@ 50ab-1 for ∆S=0

b D lit ln.b.: Dalitz analyses measuring φ1

eff

⇒σ(S) = 2 cosφ1eff σ(φ1

eff)∆S

SuperBelle, 50 ab-1

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 35 BAS, KEK, October 2009

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Summaryi t d f D lit l i flinstead of summary.... Dalitz analysis flow....

improved methodsimproved methodsgive you larger luminosity!

is Belle note on t-dependent Dalitzready?

NP!NP!

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 36 BAS, KEK, October 2009

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Bckups

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 37 BAS, KEK, October 2009

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Kinematics more J.D. Jackson, D.R. Tovey, Kinematics, in RPP,

3-body decay

decaying particle:scalar or averaging

i t tover spin states⇒integration over dΩ1*, dΩ3

213

212dmdmd

233 32

1)2(

1M

Mπ=

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 38 BAS, KEK, October 2009

6

Page 39: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Kinematics more J.D. Jackson, D.R. Tovey, Kinematics, in RPP,

3-body decay

2/)()( 222*2**2 MEEM + v

2/)(;2/)(),(

1222

21

2*2

*2

*1

*2

*112

1223

212

23

23312

2

mmmMEppEEmmmmMEpEmM

+−=⇒=+=−−=⇒+=

)cos,(cos22

*23

212

223

*23

23

2*3

22

2*2

*3

*2

23

22

223

ϑϑ

mfmmEmEEEmmm

=−−−++=

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 39 BAS, KEK, October 2009

6

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Kinematics more J.D. Jackson, D.R. Tovey, Kinematics, in RPP,

3-body decay

( ) ( )( ) ( )22

223max

223min

223*

232

cosmm

mmm−

−+=ϑ ( ) ( )min23max23 mm −

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 40 BAS, KEK, October 2009

6

Page 41: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Physics moreB → K ψ(2S)

Belle, PRL 91, 262001 (2003), 140fb-1

New states

Dalitz analysis not needed B → K X(3872)

B → K ψ(2S)(→ J/ψ π -π+)

for narrow, non-overlaping resonances(negligible interference)example: B → K J/ψ π -π+

( )(→ J/ψ π -π+)

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 41 BAS, KEK, October 2009

8

Page 42: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Physics moret d d t

Belle, PRL 99, 131803 (2007)

t-dependent Dalitz analyses

t d d [ ]titi

S tDKtmm

1

)(),,(

22

022

λλ

ππ −++− =≡M

t-dependence:regions of Dalitz plane →specific t dependence F(x, y);

[ ]

[ ]titi

titi

eemmq

eemm

21

21

),(1

),(21

22

22

λλ

λλ

−−+

−−+−

−+

++=

A

A

time evolution of Dalitz distribution⇒⇒ x, y x, y

[ ]eemmp

),(2 +−+ A

2,12121

Γ−= imλ

22,12,1

)()(

),(),(

2222

2222

Φ

+−Φ

+−

=

=

∑mmAeamm

mmAeamm

BWi

r

BWr

ir

r

r

A

A

,,

),(),( −++−

Φ=Φ=⎯⎯⎯ →⎯

= ∑aa

mmAeamm

rrrrDCPVno

rrrA

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 42 BAS, KEK, October 2009

),(),( 2222−++− = mmmm AA 28

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Physics moreBelle, PRD79, 072004 (2009), , ( )

sin 2φ1eff in b → sqq

ci determines amount of DCPVci determines amount of DCPV

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 43 BAS, KEK, October 2009

31

Page 44: Dalitz analysesDalitz analyses Introduction - IJSgolob/sola/Dalitz_BAS09_20090913.pdf · Dalitz analysesDalitz analyses Introduction Belle Analysis School ... in RPP () Γ= Φn n

Physics moreBelle, PRD79, 072004 (2009), , ( )

sin 2φ1eff in b → sqq

vtx reconstr (non-scaling)vtx reconstr. (non-scaling)improved with better tracking

bkg model (scaling)CPV in bkg; improved with measurements of contributing modes e g ’Ks

⎩⎨⎧≤

s

sKKfS ϕσ 06.0

04.0)( 0 @ 50 ab-1

of contributing modes – e.g. η Kssig. model (non-scaling)misreconstructed events; comparison with MC with correct reconstr.

D lit d l ( li )

some syst. errors cancel in ∆S = S(sqq)-S(J/ψKs)

⎧ Kf030Dalitz model (scaling)parametr. of NR; inclusion of other resonances;

⎩⎨⎧≤∆

s

sKKfS ϕσ 05.0

03.0)( 0

for ∆S=0

n.b.: Dalitz analyses measuring φ1eff ⇒σ(S) = 2 cosφ1

eff σ(φ1eff)

B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 44 BAS, KEK, October 2009