Patricia Ball

WG 2 – Theory SummaryPatricia Ball

IPPP, Durham

Patricia Ball

Topics: Weak decays, CP violation, CKM

5 theory talks:

M. Gorbahn: K physics

F. Mescia: B mixing and lifetimes from lattice

M. Gorbahn: rare inclusive B decays

F. Schwab: B → ππ, B → Kπ and implications for rare decays

I. Bigi: semileptonic B decays

O – p.1

Patricia Ball

Topics: Weak decays, CP violation, CKM

top & charm decays, D–D̄ mixing

τ decays & CP violation

lepton flavour violation

K decays & CP violation

B decays, B mixing & CP violation

5 theory talks:

M. Gorbahn: K physics

F. Mescia: B mixing and lifetimes from lattice

M. Gorbahn: rare inclusive B decays

F. Schwab: B → ππ, B → Kπ and implications for rare decays

I. Bigi: semileptonic B decays

O – p.1

Patricia Ball

Topics: Weak decays, CP violation, CKM

top & charm decays, D–D̄ mixing

τ decays & CP violation

lepton flavour violation

K decays & CP violation

B decays, B mixing & CP violationdue to time-constraints etc.

5 theory talks:

M. Gorbahn: K physics

F. Mescia: B mixing and lifetimes from lattice

M. Gorbahn: rare inclusive B decays

F. Schwab: B → ππ, B → Kπ and implications for rare decays

I. Bigi: semileptonic B decays

O – p.1

Patricia Ball

Topics: Weak decays, CP violation, CKM

top & charm decays, D–D̄ mixing

τ decays & CP violation

lepton flavour violation

K decays & CP violation

B decays, B mixing & CP violationdue to time-constraints etc.

5 theory talks:

M. Gorbahn: K physics

F. Mescia: B mixing and lifetimes from lattice

M. Gorbahn: rare inclusive B decays

F. Schwab: B → ππ, B → Kπ and implications for rare decays

I. Bigi: semileptonic B decays

O – p.1

Patricia Ball

Topics: Weak decays, CP violation, CKM

top & charm decays, D–D̄ mixing

τ decays & CP violation

lepton flavour violation

K decays & CP violation

B decays, B mixing & CP violationdue to time-constraints etc.

5 theory talks:

M. Gorbahn: K physics

F. Mescia: B mixing and lifetimes from lattice

M. Gorbahn: rare inclusive B decays

F. Schwab: B → ππ, B → Kπ and implications for rare decays

I. Bigi: semileptonic B decays

O – p.1

Patricia Ball

Topics: Weak decays, CP violation, CKM

top & charm decays, D–D̄ mixing

τ decays & CP violation

lepton flavour violation

K decays & CP violation

B decays, B mixing & CP violationdue to time-constraints etc.

5 theory talks:

M. Gorbahn: K physics

F. Mescia: B mixing and lifetimes from lattice

M. Gorbahn: rare inclusive B decays

F. Schwab: B → ππ, B → Kπ and implications for rare decays

I. Bigi: semileptonic B decays

O – p.1

Patricia Ball

Topics: Weak decays, CP violation, CKM

top & charm decays, D–D̄ mixing

τ decays & CP violation

lepton flavour violation

K decays & CP violation

B decays, B mixing & CP violationdue to time-constraints etc.

5 theory talks:

M. Gorbahn: K physics

F. Mescia: B mixing and lifetimes from lattice

M. Gorbahn: rare inclusive B decays

F. Schwab: B → ππ, B → Kπ and implications for rare decays

I. Bigi: semileptonic B decays

O – p.1

Patricia Ball

Topics: Weak decays, CP violation, CKM

top & charm decays, D–D̄ mixing

τ decays & CP violation

lepton flavour violation

K decays & CP violation

B decays, B mixing & CP violationdue to time-constraints etc.

5 theory talks:

M. Gorbahn: K physics

F. Mescia: B mixing and lifetimes from lattice

M. Gorbahn: rare inclusive B decays

F. Schwab: B → ππ, B → Kπ and implications for rare decays

I. Bigi: semileptonic B decays

– p.1

Patricia Ball

Why Flavour Physics?

quark mixing described by unitary CKM matrix V

unitarity depicted as unitarity triangle:∑

iVaiV

∗

bi= δab

O – p.2

Patricia Ball

Why Flavour Physics?

Precision determinations of SM flavour parameters:

quark mixing described by unitary CKM matrix V

unitarity depicted as unitarity triangle:∑

iVaiV

∗

bi= δab

O – p.2

Patricia Ball

Why Flavour Physics?

Precision determinations of SM flavour parameters:

quark mixing described by unitary CKM matrix V

unitarity depicted as unitarity triangle:∑

iVaiV

∗

bi= δab

(ρ,η)

α

βγ

Im

Re0 1

∣

∣

∣

∣

∣

Vtd

V∗

tb

Vcd

V ∗cb

∣

∣

∣

∣

∣

∣

∣

∣

∣

∣

Vud

V∗

ub

Vcd

V ∗cb

∣

∣

∣

∣

∣

-1.5

-1

-0.5

0

0.5

1

1.5

-1 -0.5 0 0.5 1 1.5 2

sin 2β

B → ρρ

B → ρρ

∆md

∆ms & ∆md

εK

εK

|Vub/Vcb|

sin 2β

α

βγ

ρη

excluded area has CL < 0.05

C K Mf i t t e r

Winter 2004

O – p.2

Patricia Ball

Why Flavour Physics?

Precision determinations of SM flavour parameters:

quark mixing described by unitary CKM matrix V

unitarity depicted as unitarity triangle:∑

iVaiV

∗

bi= δab

Exp. facilities:

Tevatron: en route to Bs mixing

BaBar (1999–2009) and Belle (1999–?): ∼500M B decays ontapeLHCb: 2007+2 (?)

K facilities at KEK, BNL;more planned at BNL (KOPIO), CERN (NA48/3), FNAL. . .

– p.2

Patricia Ball

Why Flavour Physics?

find/constrain new physics,e.g. in FCNC (flavour-changing neutral currents):

SM loop–suppressed,new physics contribu-tions (SUSY?) possiblyof same size as SM

(penguin diagram)

complementary to LHC: mass scales from LHC,couplings from B physicsor, if it will be built, a linear collider

O – p.3

Patricia Ball

Why Flavour Physics?

find/constrain new physics,e.g. in FCNC (flavour-changing neutral currents):

SM loop–suppressed,new physics contribu-tions (SUSY?) possiblyof same size as SM

(penguin diagram)

complementary to LHC: mass scales from LHC,couplings from B physicsor, if it will be built, a linear collider

– p.3

Patricia Ball

M. Gorbahn: K → πνν̄Future scenario for K → πνν

• KL → π0νν̄

– Direct CP violating ∝ ImV ∗tsVtd = η

– Only top → theory uncertainty < 3%

• K+ → π+νν̄

– ∝ V ∗tsVtd

– Small theory uncertainty

• Experiment

– Precision test of the Unitarity

Triangle

– And the Flavour Sector

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Theory uncertainty for K+ → π+νν̄ larger than for K0 → π0νν̄(charm quark contributions).NNLO calculation underway (Gorbahn et al.).

– p.4

Patricia Ball

F. Mescia: B Mixing and Lifetimes

Theoretical inputs for

mass differences ∆md, ∆msneeded for unitarity triangle determination & boundson/evidence for new physics

width differences ∆Γd, ∆Γsinput for time-dependent CP-asymmetries in Bs decays &bounds on/evidence for new physics

Method of choice: lattice calculations

Main problems:

simulation of heavy quarks mb � 1 GeV

simulation of light quarks md � 1 GeV

inclusion of sea quarks (unquenched calculations)

– p.5

Patricia Ball

F. Mescia: B Mixing and Lifetimes

– p.6

Patricia Ball

M. Gorbahn: Inclusive Rare B Decays: b → sγ

NLO analysis available (Gambino/Misiak ’01), NNLO underway (Gorbahn et al.)

– p.7

Patricia Ball

M. Gorbahn: Inclusive Rare B Decays: b → sγ

– p.8

Patricia Ball

M. Gorbahn: Inclusive Rare B Decays: b → s`+`−

Theory improvement (NNLO) underway!

– p.9

Patricia Ball

F. Schwab: B → ππ, B → Kπ

measurements in B → ππ: 3 BRs, 4 CP asymmetries

measurements in B → Kπ: 4 BRs, 5 CP asymmetries

theory: QCD factorisation (Beneke et al.) unable to describedata (more than 4σ for some BRs)

alternative: SU(3) symmetry (Buras/Fleischer et al.):extract hadronic parameters from B → ππ, plug into B → Kπ:discrepancies attributed to

enhanced electroweak penguins:

induces large effects in K → πνν̄

– p.10

Patricia Ball

I. Bigi: |Vub|, |Vcb| from inclusive decays

analysis of lepton energy & hadronic mass moments inB → Xc → `ν

theory predictions based onexpansion in αsexpansion in 1/mbglobal quark-hadron duality

6 theory parameters (|Vcb|, quark masses, some more hadronicparameters)

fit of ∼20 momentsprecise determination of |Vcb| and hadronic parameters

theoretical accuracy ∼2% limited by higher order perturbationtheory & terms suppressed by 1/m4

band higher

O – p.11

Patricia Ball

I. Bigi: |Vub|, |Vcb| from inclusive decays

analysis of lepton energy & hadronic mass moments inB → Xc → `ν

theory predictions based onexpansion in αsexpansion in 1/mbglobal quark-hadron duality

6 theory parameters (|Vcb|, quark masses, some more hadronicparameters)

fit of ∼20 momentsprecise determination of |Vcb| and hadronic parameters

theoretical accuracy ∼2% limited by higher order perturbationtheory & terms suppressed by 1/m4

band higher

O – p.11

Patricia Ball

I. Bigi: |Vub|, |Vcb| from inclusive decays

analysis of lepton energy & hadronic mass moments inB → Xc → `ν

theory predictions based onexpansion in αsexpansion in 1/mbglobal quark-hadron duality

6 theory parameters (|Vcb|, quark masses, some more hadronicparameters)

fit of ∼20 momentsprecise determination of |Vcb| and hadronic parameters

theoretical accuracy ∼2% limited by higher order perturbationtheory & terms suppressed by 1/m4

band higher

O – p.11

Patricia Ball

I. Bigi: |Vub|, |Vcb| from inclusive decays

analysis of lepton energy & hadronic mass moments inB → Xc → `ν

theory predictions based onexpansion in αsexpansion in 1/mbglobal quark-hadron duality

6 theory parameters (|Vcb|, quark masses, some more hadronicparameters)

fit of ∼20 momentsprecise determination of |Vcb| and hadronic parameters

theoretical accuracy ∼2% limited by higher order perturbationtheory & terms suppressed by 1/m4

band higher

O – p.11

Patricia Ball

I. Bigi: |Vub|, |Vcb| from inclusive decays

analysis of lepton energy & hadronic mass moments inB → Xc → `ν

theory predictions based onexpansion in αsexpansion in 1/mbglobal quark-hadron duality

6 theory parameters (|Vcb|, quark masses, some more hadronicparameters)

fit of ∼20 momentsprecise determination of |Vcb| and hadronic parameters

theoretical accuracy ∼2% limited by higher order perturbationtheory & terms suppressed by 1/m4

band higher

– p.11

Patricia Ball

I. Bigi: |Vub|, |Vcb| from inclusive decays

O – p.12

Patricia Ball

I. Bigi: |Vub|, |Vcb| from inclusive decays

global duality!

O – p.12

Patricia Ball

I. Bigi: |Vub|, |Vcb| from inclusive decays

global duality!

Shape functions? (Neubert et al.)But O(1/mb) unknown!Intrinsic theory error ∼20%?

– p.12

Patricia Ball

Conclusionsgood progress in some channels. . .

semileptonics decays, BRs of rare inclusive decays, someexclusive decays (K → πνν̄, . . . )

less progress in others. . .nonleptonic decays: QCD factorisation (Beneke et al.)violated at ∼ 40% level in B → ππ

conclusion for unitarity triangle determination:all sides and angles accessible with

Patricia Ball

Conclusionsgood progress in some channels. . .

semileptonics decays, BRs of rare inclusive decays, someexclusive decays (K → πνν̄, . . . )

less progress in others. . .nonleptonic decays: QCD factorisation (Beneke et al.)violated at ∼ 40% level in B → ππ

conclusion for unitarity triangle determination:all sides and angles accessible with

Patricia Ball

Conclusionsgood progress in some channels. . .

semileptonics decays, BRs of rare inclusive decays, someexclusive decays (K → πνν̄, . . . )

less progress in others. . .nonleptonic decays: QCD factorisation (Beneke et al.)violated at ∼ 40% level in B → ππ

conclusion for unitarity triangle determination:all sides and angles accessible with

Patricia Ball

Conclusionsgood progress in some channels. . .

semileptonics decays, BRs of rare inclusive decays, someexclusive decays (K → πνν̄, . . . )

less progress in others. . .nonleptonic decays: QCD factorisation (Beneke et al.)violated at ∼ 40% level in B → ππ

conclusion for unitarity triangle determination:all sides and angles accessible with