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Observables and anomalies in B K (*) + - decays Sam Cunliffe on behalf of the LHCb collaboration. [[email protected]] Frontiers in Fundamental Physics, Aix Marseille Universit´ e 18th July 2014

Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

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Page 1: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Observables and anomalies inB→ K(∗)`+`− decaysSam Cunliffe on behalf of the LHCb collaboration. [[email protected]]

Frontiers in Fundamental Physics, Aix Marseille Universite 18th July 2014

Page 2: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

The LHCb detector

b→ s`` TheoryThe operator-product expansionObservables, observables, observables

Isospin asymmetry of B→ K(∗)µ+µ−

Angular analysis of B0→ K∗0µ+µ−

Observables from the angular distributionLHCb measurement

InterpretationsGlobal fitsForm factor uncertainties

Lepton universality in B±→ K±`+`−

Something strange from charm

Conclusions

S.Cunliffe (Imperial) FFP14 2/21

Page 3: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

I ‘Rare’ Flavour-Changing Neutral Current processesI Forbidden at tree level =⇒ proceed via loops (in SM)

sb

µ−

µ+

W−

Z0, γ

I Searching for new particles via their indirect influence on rare processesI Access to much higher mass scales (particles are virtual)I Able to be model independentI Search for broad classes of new particles at once

I For other flavour observables (and another perspective on b→ s``), see talkby F. Mescia, yesterday

S.Cunliffe (Imperial) FFP14 Why study rare decays? 3/21

Page 4: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

I If you want to learn about space...I If you want to find new particles...

χ

χ

q

q

STS-I Launch - NASA/CC [Source]

sb

µ−

µ+

W−

Z0, γ

d d

sb

µ−

µ+

g

H0

d d

d

sb

µ−

µ+

W−

Z ′

d d

sb

µ−

µ+

Z ′

d d

Very Large Array - Image courtesy of NRAO/AUI [Source]

S.Cunliffe (Imperial) FFP14 Why study rare decays? 4/21

Page 5: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

I If you want to learn about space...I If you want to find new particles...

χ

χ

q

q

CMS Monojet candidate - [Source]

sb

µ−

µ+

W−

Z0, γ

d d

sb

µ−

µ+

g

H0

d d

d

sb

µ−

µ+

W−

Z ′

d d

sb

µ−

µ+

Z ′

d d

S.Cunliffe (Imperial) FFP14 Why study rare decays? 4/21

Page 6: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

I If you want to learn about space...I If you want to find new particles...

χ

χ

q

q

sb

µ−

µ+

W−

Z0, γ

d d

sb

µ−

µ+

g

H0

d d

d

sb

µ−

µ+

W−

Z ′

d d

sb

µ−

µ+

Z ′

d d

S.Cunliffe (Imperial) FFP14 Why study rare decays? 4/21

Page 7: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

I If you want to learn about space...I If you want to find new particles...

χ

χ

q

q

sb

µ−

µ+

W−

Z0, γ

d d

sb

µ−

µ+

g

H0

d d

d

sb

µ−

µ+

W−

Z ′

d d

sb

µ−

µ+

Z ′

d d

S.Cunliffe (Imperial) FFP14 Why study rare decays? 4/21

Page 8: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

I If you want to learn about space...I If you want to find new particles...

χ

χ

q

q

sb

µ−

µ+

W−

Z0, γ

d d

sb

µ−

µ+

g

H0

d d

d

sb

µ−

µ+

W−

Z ′

d d

sb

µ−

µ+

Z ′

d d

S.Cunliffe (Imperial) FFP14 Why study rare decays? 4/21

Page 9: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

I If you want to learn about space...I If you want to find new particles...

χ

χ

q

q

sb

µ−

µ+

W−

Z0, γ

d d

sb

µ−

µ+

g

H0

d d

d

sb

µ−

µ+

W−

Z ′

d d

sb

µ−

µ+

Z ′

d d

S.Cunliffe (Imperial) FFP14 Why study rare decays? 4/21

Page 10: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

The LHCb detector

b→ s`` TheoryThe operator-product expansionObservables, observables, observables

Isospin asymmetry of B→ K(∗)µ+µ−

Angular analysis of B0→ K∗0µ+µ−

Observables from the angular distributionLHCb measurement

InterpretationsGlobal fitsForm factor uncertainties

Lepton universality in B±→ K±`+`−

Something strange from charm

Conclusions

Page 11: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

The LHCb detectorBeauty Experiment at Small Theta

I Physics reach in other areas than rare b→ s``observables...

I e.g. talks by J. Dalseno on CPV in multibody Bdecaysand B. Couturier on LHCb outreach/education

I 2 < η < 5

I Tracking:0.4 < δp/p < 0.6%

I Vertexing:σIP = 20µm

I Kaon ID = 95%(5% mis-ID)

I Muon ID = 98%(1% mis-ID)

0/4π

/2π/4π3

π

0

/4π

/2π

/4π3

π [rad]1θ

[rad]2θ

b

b

z

LHCb MC = 8 TeVs

S.Cunliffe (Imperial) FFP14 The LHCb detector 5/21

Page 12: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

The LHCb detector

b→ s`` TheoryThe operator-product expansionObservables, observables, observables

Isospin asymmetry of B→ K(∗)µ+µ−

Angular analysis of B0→ K∗0µ+µ−

Observables from the angular distributionLHCb measurement

InterpretationsGlobal fitsForm factor uncertainties

Lepton universality in B±→ K±`+`−

Something strange from charm

Conclusions

Page 13: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

The operator-product expansionOr: how to be model independent

sb

µ−

µ+

W−

Z0, γ

d d

sb

µ−

µ+

W−

W+

νµ

dd

S.Cunliffe (Imperial) FFP14 b→ s`` Theory 6/21

Page 14: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

The operator-product expansionOr: how to be model independent

sb

γ

“O7”“C7”

sb

ℓ+

ℓ−“O9”, “O10”“C9”, “C10”

I “Effective operators” OiI “Wilson Coefficients” Ci

I c.f. GF from 4 point β decay modelI Can predict Ci’s for SM and NP scenarios

I Have an effective Hamiltonian =⇒ can calculate things

Heff = −4GF√2

e2

16π2VtbV

∗ts

∑i=7,9,10

(CiOi + C′iO′i

)+ h.c.

S.Cunliffe (Imperial) FFP14 b→ s`` Theory 7/21

Page 15: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

The operator-product expansionOr: how to be model independent

sb

γ

“O7”“C7”

sb

ℓ+

ℓ−“O9”, “O10”“C9”, “C10”

I “Effective operators” OiI “Wilson Coefficients” Ci

I c.f. GF from 4 point β decay modelI Can predict Ci’s for SM and NP scenarios

I Have an effective Hamiltonian =⇒ can calculate things

Heff = −4GF√2

e2

16π2VtbV

∗ts

∑i=7,9,10

(CiOi + C′iO′i

)+ h.c.

S.Cunliffe (Imperial) FFP14 b→ s`` Theory 7/21

Page 16: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

The operator-product expansionOr: how to be model independent

sb

γ

“O7”“C7”

sb

ℓ+

ℓ−“O9”, “O10”“C9”, “C10”

I “Effective operators” OiI “Wilson Coefficients” Ci

I c.f. GF from 4 point β decay modelI Can predict Ci’s for SM and NP scenarios

I Have an effective Hamiltonian =⇒ can calculate things

Heff = −4GF√2

e2

16π2VtbV

∗ts

∑i=7,9,10

(CiOi + C′iO′i

)+ h.c.

S.Cunliffe (Imperial) FFP14 b→ s`` Theory 7/21

Page 17: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

The operator-product expansionOr: how to be model independent

sb

γ

“O7”“C7”

sb

ℓ+

ℓ−“O9”, “O10”“C9”, “C10”

I “Effective operators” OiI “Wilson Coefficients” Ci

I c.f. GF from 4 point β decay modelI Can predict Ci’s for SM and NP scenarios

I Have an effective Hamiltonian =⇒ can calculate things

Heff = −4GF√2

e2

16π2VtbV

∗ts

∑i=7,9,10

(CiOi + C′iO′i

)+ h.c.

S.Cunliffe (Imperial) FFP14 b→ s`` Theory 7/21

Page 18: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

A word on QCDEnter form factor uncertainty

I Observables also contain contributions Hadronic Form Factors.I Different theorists use different versions/approximations.

O = f (Ci, {form factors})

sb

µ−

µ+

W−

Z0, γ

d d

S.Cunliffe (Imperial) FFP14 b→ s`` Theory 8/21

Page 19: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

A word on QCDEnter form factor uncertainty

I Observables also contain contributions Hadronic Form Factors.I Different theorists use different versions/approximations.

O = f (Ci, {form factors})

sb

µ−

µ+

W−

Z0, γ

d d

sb

µ−

µ+

d d

S.Cunliffe (Imperial) FFP14 b→ s`` Theory 8/21

Page 20: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

O7

b→ s``cos θK

q2

V (q2)

T3(q2)

AL⊥

A2(q2)ξ⊥C9

S6

P ′5C7

CNP9

AFB

|AR‖ |2

P ′4

b→ sγ Jc1

ξ‖Js2

Nomenclature

Page 21: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

O7

b→ s``cos θK

q2

V (q2)

T3(q2)

AL⊥

A2(q2)ξ⊥C9

S6

P ′5C7

CNP9

AFB

|AR‖ |2

P ′4

b→ sγ Jc1

ξ‖Js2

Nomenclature

q2 = m2``

Squared dileptoninvariant mass

Page 22: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Observables, observables, observables

I Need to find measurable quantities that...I ...are sensitive to the Wilson CoefficientsI ...cancel the QCD uncertainty (hadronic form factors) wherever possible

Lepton-universality

RK =B[B±→ K±µ+µ−

]B[B±→ K±e+e−

]

Isospin asymmetry (spectator-model-asymmetry)

AI =B[B0→ K(∗)0µ+µ−

]− τ

B0

τB+B[B±→ K(∗)±µ+µ−

]B[B0→ K(∗)0µ+µ−

]+

τB0

τB+B[B±→ K(∗)±µ+µ−

]

S.Cunliffe (Imperial) FFP14 b→ s`` Theory 10/21

Page 23: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

The LHCb detector

b→ s`` TheoryThe operator-product expansionObservables, observables, observables

Isospin asymmetry of B→ K(∗)µ+µ−

Angular analysis of B0→ K∗0µ+µ−

Observables from the angular distributionLHCb measurement

InterpretationsGlobal fitsForm factor uncertainties

Lepton universality in B±→ K±`+`−

Something strange from charm

Conclusions

Page 24: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Isospin asymmetry of B→ K(∗)µ+µ−

[J. High Energy Phys. 06 (2014) 133]

I Measure asymmetry in ratebetween neutral and chargedmodes

I B0→ K∗0(→ K±π∓)µ+µ−

I B±→ K∗±(→ K0Sπ±)µ+µ−

I B0→ K0Sµ

+µ−

I B±→ K±µ+µ−

I Asymmetry v.close to zero in SMI Experimental challenge:

I K0S → π+π− reconstruction

I Normalise toB→ J/ψ (→ µ+µ−)K(∗)

I 3 fb−1 2011+2012 data

]2c) [MeV/−µ+µ−π+K(m5200 5400 5600

)2 cC

andi

date

s / (

10

MeV

/

0

200

400 LHCb

−µ+µ *0K → 0B

]2c) [MeV/−µ+µ+πS0K(m

5200 5400 5600

)2 cC

andi

date

s / (

10

MeV

/

0

20

40

60

LHCb

−µ+µ *+K → +B

S.Cunliffe (Imperial) FFP14 Isospin asymmetry ofB→ K(∗)µ+µ− 11/21

Page 25: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Isospin asymmetry of B→ K(∗)µ+µ−

AI =B[B0→ K(∗)0µ+µ−

]− τ

B0

τB+B[B±→ K(∗)±µ+µ−

]B[B0→ K(∗)0µ+µ−

]+

τB0

τB+B[B±→ K(∗)±µ+µ−

]

]4c/2 [GeV2q0 5 10 15 20

IA

-1

-0.5

0

0.5

1

LHCb −µ+µ K →B *

]4c/2 [GeV2q0 5 10 15 20

IA

-1

-0.5

0

0.5

1

LHCb −µ+µ K →B

I Consistent with SM. (AI ≈ 0)

S.Cunliffe (Imperial) FFP14 Isospin asymmetry ofB→ K(∗)µ+µ− 12/21

Page 26: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

The LHCb detector

b→ s`` TheoryThe operator-product expansionObservables, observables, observables

Isospin asymmetry of B→ K(∗)µ+µ−

Angular analysis of B0→ K∗0µ+µ−

Observables from the angular distributionLHCb measurement

InterpretationsGlobal fitsForm factor uncertainties

Lepton universality in B±→ K±`+`−

Something strange from charm

Conclusions

Page 27: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Observables from the angular distribtionForB0 → K∗(892)0(→ K±π∓)µ+µ− decays...

I P → V V ′ (pseudoscalar to vector-vector)I Vector K∗(892) =⇒ angular distribution, as well as rate, is interesting

B0

K* 0

K+

π - μ -

μ+

θKθℓ

φ

I 3 angles, and q2{θK , θ`, φ, q

2}

I Angular distribution −→ Sets of observables:{FL, AFB, A

2T, S9

} {P ′4, P ′5, P ′6, P ′8}

I ...Clever ratios of angular terms

S.Cunliffe (Imperial) FFP14 Angular analysis ofB0→ K∗0µ+µ− 13/21

Page 28: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Observables from the angular distribtionForB0 → K∗(892)0(→ K±π∓)µ+µ− decays...

I P → V V ′ (pseudoscalar to vector-vector)I Vector K∗(892) =⇒ angular distribution, as well as rate, is interesting

B0

K* 0

K+

π - μ -

μ+

θKθℓ

φ

I 3 angles, and q2{θK , θ`, φ, q

2}

I Angular distribution −→ Sets of observables:{FL, AFB, A

2T, S9

} {P ′4, P ′5, P ′6, P ′8}

I ...Clever ratios of angular terms

S.Cunliffe (Imperial) FFP14 Angular analysis ofB0→ K∗0µ+µ− 13/21

Page 29: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Angular analysis of B0→ K∗0µ+µ−

[Phys. Rev. Lett. 111 (2013) 191801]

I Fit a reduced angular distributionI 3D fit, binned in q2{

P ′4, P′5, P

′6, P

′8

}I Correct for detector acceptance

I Observe local 3.7σ deviationfrom SM [JHEP 1305 (2013) 137]

I Prob. for 24 independentobservations (4P ’s × 6q2 bins) is0.5%

I 1 fb−1 2011 data

]4c/2 [GeV2q0 5 10 15 20

'4

P

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

SM Predictions

Data

LHCb

]4c/2 [GeV2q0 5 10 15 20

'5

P

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

SM Predictions

Data

LHCb

S.Cunliffe (Imperial) FFP14 Angular analysis ofB0→ K∗0µ+µ− 14/21

Page 30: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

The LHCb detector

b→ s`` TheoryThe operator-product expansionObservables, observables, observables

Isospin asymmetry of B→ K(∗)µ+µ−

Angular analysis of B0→ K∗0µ+µ−

Observables from the angular distributionLHCb measurement

InterpretationsGlobal fitsForm factor uncertainties

Lepton universality in B±→ K±`+`−

Something strange from charm

Conclusions

Page 31: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Global fitsP ′5 ⇒ tension inC9

Descotes-Genon, Matias & Virto[Phys. Rev. D 88, 074002 (2013)]

I Global fit including {P ′4, P ′5, P ′6, P ′8}I Fit includes b→ s`` and b→ sγ inputsI 4.5σ discrepancy from SM pointI Favours CNP

9 ≈ −1.5

68.3% C.L

95.5% C.L

99.7% C.L

Includes Low Recoil data

Only @1,6D bins

SM

-0.15 -0.10 -0.05 0.00 0.05 0.10 0.15

-4

-2

0

2

4

C7NP

C9N

P

Altmannshofer & Straub[Eur. Phys. J. C (2013) 73: 2646]

I 3σ discrepancyI Differences:

I Definitions of observablesI Different q2 rangesI Theory assumptions

I Best fit is modified C9

I Data described by additional Z′ at ∼ 7TeV

I Hard to reconcile with MSSM-3 -2 -1 0 1 2 3

-3

-2

-1

0

1

2

3

ReHC9NPL

ReHC

9' LFL

S4

S5

AFB

B®K

ΜΜ

S.Cunliffe (Imperial) FFP14 Interpretations 15/21

Page 32: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

A hint of new physics?Contributions from new Z′ vector?

Descotes-Genon, et al.[JHEP 1305 (2013) 137)]

I Originally motivated {Pi}observables

I Simplification (assumption) inchoice of form factors

]4c/2 [GeV2q0 5 10 15 20

'5

P

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

SM Predictions

Data

LHCb

3.7σ

Jager & Camlich[JHEP 1305 (2013) 043]

I Uncertainty due to simplifiedchoice of form factors(factorisable corrections areunderestimated)

S.Cunliffe (Imperial) FFP14 Interpretations 16/21

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A hint of new physics?...or underestimated errors

Descotes-Genon, et al.[JHEP 1305 (2013) 137)]

I Originally motivated {Pi}observables

I Simplification (assumption) inchoice of form factors

]4c/2 [GeV2q0 5 10 15 20

'5

P

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

SM Predictions

Data

LHCb

3.7σ

Jager & Camlich[JHEP 1305 (2013) 043]

I Uncertainty due to simplifiedchoice of form factors(factorisable corrections areunderestimated)

B0→K*0µµ : interpretation

∃∀

•  Global fits → 2-4σ tension

•  Views from the theory community:

–  P5’ tension correlated with other

(smaller) tensions and NP explanation consistent with all

measurements is possible [1,2]

–  Theory errors underestimated,

tension is reduced [3]

•  Difficult to explain with SUSY [1]

•  Consistent with a Z’ with mass ~ 7 TeV (!) [4]

→ Measure other B→Kµµ decays!

∀%&∋()∗+,#,−.#//01∀

]4c/2 [GeV2q

0 5 10 15 20

'5

P

-1

0

1

SM arXiv:1303.5794

SM arXiv:1212.2263

-1LHCb 1fb

%,1∀2345&66789:;∋∀;4∀&3.<∀&∋()∗+,#−/.,=−,>∀%!1∀?;7≅94;7ΑΒ;696∀;4∀&3.<∀Χ8∆7.∀Ε;∗.∀?∀//<∀−0∃−−!∀Φ!−,#Γ<∀Η9∋Ι&6∀

;4∀&3.<∀&∋()∗+,#,−.#//0>∀%#1∀ϑ;&ΚΛ;&6∀;4∀&3.<∀&∋()∗+,#,−.!∃0/<∀Μ&;Ι;∋∀;4∀&3.<∀&∋()∗+,!,!.!!Ν#>∀%∃1∀Β&Κ3Ο∀;4∀&3.<∀

ΜΗΠΧ∀,∃−,∀Φ!−,∃Γ∀−ΝΘ<∀ϑΚ∋&7∀;4∀&3.<∀&∋()∗+,#,,.Ν0!Θ∀

S.Cunliffe (Imperial) FFP14 Interpretations 16/21

Page 34: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

The LHCb detector

b→ s`` TheoryThe operator-product expansionObservables, observables, observables

Isospin asymmetry of B→ K(∗)µ+µ−

Angular analysis of B0→ K∗0µ+µ−

Observables from the angular distributionLHCb measurement

InterpretationsGlobal fitsForm factor uncertainties

Lepton universality in B±→ K±`+`−

Something strange from charm

Conclusions

Page 35: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Lepton universality in B±→ K±`+`−

[arXiv:1406.6482] submitted: Phys.Rev.Lett

RK =B[B±→ K±µ+µ−

]B[B±→ K±e+e−]

I If a Z′ is responsible for P ′5 does itcouple equally to lepton flavours?

I Altmannshofer et al.[Phys. Rev. D89 (2014) 095033]

I Kruger & Hiller[Phys.Rev. D69 (2004) 074020]

I Experimental challenge:I Selection of B±→ K±e+e−

I Bremsstrahlung → q2 movementI Correct for bremsstrahlung with

calorimeter photonsI Migration in q2 corrected with

simulationI 3 fb−1 2011+2012 data

]2c) [MeV/−e+e

+K(m

5000 5200 5400 5600

)2c

Can

did

ate

s /

( 4

0 M

eV

/

0

5

10

310×

LHCb

(a)B±→ J/ψK±

]2c) [MeV/−

e+e+

K(m

5000 5200 5400 5600

)2c

Can

did

ate

s /

( 4

0 M

eV

/

0

10

20

30

40 LHCb

(d)B±→ K±e+e−

S.Cunliffe (Imperial) FFP14 Lepton universality inB±→ K±`+`− 17/21

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Lepton universality in B±→ K±`+`−

I Experimentally, use double ratio with B±→ J/ψK± decaysI Cancels systematic biases

RK =NK±µ+µ−

NJ/ψ (µ+µ−)K±

NJ/ψ (e+e−)K±

NK±e+e−×εJ/ψ (µ+µ−)K±

εK±µ+µ−

εK±e+e−

εJ/ψ (e+e−)K±

where Nf is the observed yield for B±→ f and εf is the corresponding efficiency

I RK = 1.000 in SM (argue aboutthe 4th s.f.)

I SM Higgs v.suppressedI LHCb measuresRK = 0.745+0.090

−0.074 ± 0.036

I In range q2 ∈ [1, 6]GeV2/c4

I Only agrees with SM within 2.6σ ]4c/2 [GeV2q0 5 10 15 20

KR

0

0.5

1

1.5

2

SM

LHCbLHCb

LHCb BaBar Belle

BaBar: [Phys. Rev. D86 (2012) 032012]

Belle: [Phys.Rev.Lett. 103 (2009) 171801]

S.Cunliffe (Imperial) FFP14 Lepton universality inB±→ K±`+`− 18/21

Page 37: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

The LHCb detector

b→ s`` TheoryThe operator-product expansionObservables, observables, observables

Isospin asymmetry of B→ K(∗)µ+µ−

Angular analysis of B0→ K∗0µ+µ−

Observables from the angular distributionLHCb measurement

InterpretationsGlobal fitsForm factor uncertainties

Lepton universality in B±→ K±`+`−

Something strange from charm

Conclusions

Page 38: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Something strange from charm

3.7 3.8 3.9 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5.0-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

Rexp

Rthe

Rcon

Rint

Rres

RBW

R

Ecm(GeV)

χ2/d.o.f=1.05

BESII e+e−→ hadrons/e+e−→ µ+µ−

0

0.5

1

1.5

2

2.5

3

3.5

3.6 3.8 4 4.2 4.4 4.6

dB

r

d√

q2[B

+→

K+µµ]/

10−

7G

eV−

1

!q2/GeV

Ψ(3770)

Ψ(4040)

Ψ(4160)

Ψ(4400)

a) afacb) ηcafacc) ρr ∈ Rd) ρr ∈ CLHCb

(4415)

(2S)

LHCb data: B±→ K±µ+µ−, L&Z fits

Lyon & Zwicky[arXiv:1406.0566]

I Fit BESII and LHCb dataI Necessary to add in large corrections (fudge factors) to get good fitI Are we underestimating the non-factorisable effects in Ceff

9 ?I Could explain P ′5 effectI And/or motivate new physics studies in b→ ccs operators

S.Cunliffe (Imperial) FFP14 Something strange from charm 19/21

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Something strange from charm (loops)

cc

O1,2

ℓℓ

γ(q)

b s

(a) (b)ℓ

O1,2

ℓℓ

γ(q)

b s

J/Ψ, Ψ′..

O1,2

ℓℓ

γ(q)

b s

O1,2

ℓℓ

γ(q)

b s

O1,2b s

cc

O1,2b s OG

b sg

ℓℓℓ

γ(q)ℓ ℓ

(c)

I Massively underestimated terms like (a) at low q2

I The green gluons can’t account for this

S.Cunliffe (Imperial) FFP14 Something strange from charm 20/21

Page 40: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Why study rare decays?

The LHCb detector

b→ s`` TheoryThe operator-product expansionObservables, observables, observables

Isospin asymmetry of B→ K(∗)µ+µ−

Angular analysis of B0→ K∗0µ+µ−

Observables from the angular distributionLHCb measurement

InterpretationsGlobal fitsForm factor uncertainties

Lepton universality in B±→ K±`+`−

Something strange from charm

Conclusions

Page 41: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Conclusions

I FCNC processes probe higher mass scales for NPI Formalism gives model-independenceI Observables!

I Interesting results in b→ s`` processesI Isospin asymmetry in B→ K(∗)µ+µ−

I Angular analyses of B0→ K∗0µ+µ−

I Lepton universality in B±→ K±`+`−

I Interest from our theory/phenomenology friends

I LHCb data-taking in 2015...I Belle-II physics runs late 2016...

S.Cunliffe (Imperial) FFP14 Conclusions 21/21

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[Backup Slides]

Page 43: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

The actual definitions of the Wilson Operators

Heff = −4GF√2

e2

16π2VtbV

∗ts

∑i=7,9,10

(CiOi + C′iO′i

)+ h.c.

O7 =e

g2mb(sσµνPRb)F

µν , O′7 =e

g2mb(sσµνPLb)F

µν ,

O9 =e2

g2(sγµPLb)(¯γµ`), O′9 =

e2

g2(sγµPRb)(¯γµ`),

O10 =e2

g2(sγµPLb)(¯γµγ5`), O′10 =

e2

g2(sγµPRb)(¯γµγ5`),

S.Cunliffe (Imperial) FFP14 Backup 23/21

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The actual definitions of the Wilson Operators

Ci = CSMi + CNP

i , C′i = C′ SMi + C′NP

i .

I @ right-handed interactions i = 9, 10 operators in SM

C′ SM9,10 = 0

I ∃ helicity-suppressed right-handed SM contributions to O′7 so

C′7 =ms

mb(CSM

7 + CNP7 ) + C′NP

7 .

S.Cunliffe (Imperial) FFP14 Backup 24/21

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Angular distribution of B0→ K∗0µ+µ−

The distribution of for vectorK∗0(892)

d4Γ

d cos θKd cos θldφdq2=

9

32π

(Js1 sin2 θK + Jc1 cos2 θK

+ (Js2 sin2 θK + Jc2 cos2 θK) cos 2θ`

+ J3 sin2 θK sin2 θ` cos 2φ

+ J4 sin 2θK sin 2θ` cosφ

+ J5 sin 2θK sin θ` cosφ

+ J6 sin2 θK cos θ`

+ J7 sin 2θK sin θ` sinφ

+ J8 sin 2θK sin 2θ` sinφ

+ J9 sin2 θK sin2 θ` sin 2φ

)

S.Cunliffe (Imperial) FFP14 Backup 25/21

Page 46: Observables and anomalies in - ffp14.cpt.univ-mrs.frffp14.cpt.univ-mrs.fr/DOCUMENTS/SLIDES/CUNLIFFE_Sam.pdf · Observables, observables, observables Isospin asymmetry of B! K( ) +

Angular distribution of B0→ K∗0µ+µ−

The principle moments

J1s =3

4

[|AL⊥|2 + |AL‖ |2 + |AR⊥|2 + |AR‖ |2

]J1c = |AL0 |2 + |AR0 |2

J2s =1

4

[|AL⊥|2 + |AL‖ |2 + |AR⊥|2 + |AR‖ |2

]J2c = −

[|AL0 |2 + |AR0 |2

]J3 =

1

2

[|AL⊥|2 − |AL‖ |2 + |AR⊥|2 − |AR‖ |2

]J4 =

1√2

[<(AL0A

L∗‖ +AR0 A

R∗‖ )]

J5 =√

2[<(AL0A

L∗⊥ −AR0 AR∗⊥ )

]J6 = 2

[<(AL‖A

L∗⊥ −AR‖ AR∗⊥ )

]J7 =

√2[=(AL0A

L∗‖ −AR0 AR∗‖ )

]J8 =

1√2

[=(AL0A

L∗⊥ −AR0 AR∗⊥ )

]J9 = =(AL∗‖ AL⊥ +AR∗‖ AR⊥).

(1)

S.Cunliffe (Imperial) FFP14 Backup 26/21

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The AmplitudesCalculated in the effective field theory

AL,R⊥ = N√

2λ1/2

[ [(Ceff

9 + Ceff′9 )∓ (Ceff

10 + Ceff′10 )] V (q2)

mB +mK∗

+2mb

q2(Ceff

7 + Ceff′7 )T1(q2)

],

AL,R‖ = −N√

2(m2B −m2

K∗)

[ [(Ceff

9 − Ceff′9 )∓ (Ceff

10 − Ceff′10 )] A1(q2)

mB −mK∗

+2mb

q2(Ceff

7 − Ceff′7 )T2(q2)

],

AL,R0 = − N

2mK∗∗√q2

{[(Ceff

9 − Ceff′9 )∓ (Ceff

10 − Ceff′10 )]

×[(m2

B −m2K∗∗ − q2)(mB +mK∗∗)A1(q2)− λ A2(q2)

mB +mK∗∗

]+ 2mb(C

eff7 − Ceff′

7 )

[(m2

B + 3m2K∗∗ − q2)T2(q2)− λ

m2B −m2

K∗∗T3(q2)

]},

S.Cunliffe (Imperial) FFP14 Backup 27/21

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The AmplitudesCalculated in the effective field theory

...where

N = VtbV∗ts

[G2Fα

2

3 · 210π5m3B

q2λ1/2βµ

]1/2

,

with λ = m4B +m4

K∗ + q4 − 2(m2Bm

2K∗ +m2

K∗q2 +m2

Bq2) and

βµ =√

1− 4m2µ/q2.

S.Cunliffe (Imperial) FFP14 Backup 28/21

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What are the Pi observables?

P ′i ≡Si√

FL(1− FL)=

1

2

1

dΓ/dq2

Ji + Ji√FL(1− FL)

P ′5 ≡1

2

1

dΓ/dq2

√2[<(AL0A

L∗⊥ −AR0 AR∗⊥ )

]√FL(1− FL)

I The asymmetry of the cross term between the longitudinal andperpendicularly polarised amplitudes.

S.Cunliffe (Imperial) FFP14 Backup 29/21