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Observables and anomalies in B K ( ) + decays Sam Cunliffe on - - PowerPoint PPT Presentation

Observables and anomalies in B K ( ) + decays Sam Cunliffe on behalf of the LHCb collaboration. [stc09@ic.ac.uk] Frontiers in Fundamental Physics, Aix Marseille Universit e 18th July 2014 Why study rare decays? The LHCb


slide-1
SLIDE 1

Observables and anomalies in B → K(∗)ℓ+ℓ− decays

Sam Cunliffe on behalf of the LHCb collaboration.

[stc09@ic.ac.uk]

Frontiers in Fundamental Physics, Aix Marseille Universit´ e 18th July 2014

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SLIDE 2

Why study rare decays? The LHCb detector b→ sℓℓ Theory The operator-product expansion Observables, observables, observables Isospin asymmetry of B → K(∗)µ+µ− Angular analysis of B0 → K∗0µ+µ− Observables from the angular distribution LHCb measurement Interpretations Global fits Form factor uncertainties Lepton universality in B± → K±ℓ+ℓ− Something strange from charm Conclusions

S.Cunliffe (Imperial) FFP14 2/21

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SLIDE 3

Why study rare decays?

◮ ‘Rare’ Flavour-Changing Neutral Current processes

◮ Forbidden at tree level =

⇒ proceed via loops (in SM) s b µ− µ+ W − Z0, γ

◮ Searching for new particles via their indirect influence on rare processes

◮ Access to much higher mass scales (particles are virtual) ◮ Able to be model independent ◮ Search for broad classes of new particles at once

◮ For other flavour observables (and another perspective on b→ sℓℓ), see talk

by F. Mescia, yesterday

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

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SLIDE 4

Why study rare decays?

◮ If you want to learn about space... ◮ If you want to find new particles... STS-I Launch - NASA/CC [Source] Very Large Array - Image courtesy of NRAO/AUI [Source]

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

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SLIDE 5

Why study rare decays?

◮ If you want to learn about space... ◮ If you want to find new particles... CMS Monojet candidate - [Source]

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

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SLIDE 6

Why study rare decays?

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

¯ χ χ q ¯ q

s b µ− µ+ W − Z0, γ ¯ d ¯ d

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

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SLIDE 7

Why study rare decays?

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

¯ χ χ q ¯ q

s b µ− µ+ ˜ g ˜ H0 ¯ d ¯ d ˜ d

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

slide-8
SLIDE 8

Why study rare decays?

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

¯ χ χ q ¯ q

s b µ− µ+ W − Z′ ¯ d ¯ d

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

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SLIDE 9

Why study rare decays?

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

¯ χ χ q ¯ q

s b µ− µ+ Z′ ¯ d ¯ d

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

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SLIDE 10

Why study rare decays? The LHCb detector b→ sℓℓ Theory The operator-product expansion Observables, observables, observables Isospin asymmetry of B → K(∗)µ+µ− Angular analysis of B0 → K∗0µ+µ− Observables from the angular distribution LHCb measurement Interpretations Global fits Form factor uncertainties Lepton universality in B± → K±ℓ+ℓ− Something strange from charm Conclusions

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SLIDE 11

The LHCb detector

Beauty Experiment at Small Theta

◮ Physics reach in other areas than rare b→ sℓℓ

  • bservables...

◮ e.g. talks by J. Dalseno on CPV in multibody B

decays and B. Couturier on LHCb outreach/education

◮ 2 < η < 5 ◮ Tracking:

0.4 < δp/p < 0.6%

◮ Vertexing:

σIP = 20 µm

◮ Kaon ID = 95%

(5% mis-ID)

◮ Muon ID = 98%

(1% mis-ID)

/4 π /2 π /4 π 3 π /4 π /2 π /4 π 3 π

[rad]

1

θ [rad]

2

θ

1

θ

2

θ b b

z

LHCb MC = 8 TeV s

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

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SLIDE 12

Why study rare decays? The LHCb detector b→ sℓℓ Theory The operator-product expansion Observables, observables, observables Isospin asymmetry of B → K(∗)µ+µ− Angular analysis of B0 → K∗0µ+µ− Observables from the angular distribution LHCb measurement Interpretations Global fits Form factor uncertainties Lepton universality in B± → K±ℓ+ℓ− Something strange from charm Conclusions

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SLIDE 13

The operator-product expansion

Or: how to be model independent

s b µ− µ+ W − Z0, γ ¯ d ¯ d s b µ− µ+ W − W + νµ ¯ d ¯ d

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

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SLIDE 14

The operator-product expansion

Or: how to be model independent

s b γ

“O7” “C7”

s b ℓ+ ℓ−

“O9”, “O10” “C9”, “C10”

◮ “Effective operators” Oi ◮ “Wilson Coefficients” Ci

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

◮ Have an effective Hamiltonian =

⇒ can calculate things Heff = −4GF √ 2 e2 16π2 VtbV ∗

ts

  • i=7,9,10
  • CiOi + C′

iO′ i

  • + h.c.

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

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SLIDE 15

The operator-product expansion

Or: how to be model independent

s b γ

“O7” “C7”

s b ℓ+ ℓ−

“O9”, “O10” “C9”, “C10”

◮ “Effective operators” Oi ◮ “Wilson Coefficients” Ci

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

◮ Have an effective Hamiltonian =

⇒ can calculate things Heff = −4GF √ 2 e2 16π2 VtbV ∗

ts

  • i=7,9,10
  • CiOi + C′

iO′ i

  • + h.c.

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

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SLIDE 16

The operator-product expansion

Or: how to be model independent

s b γ

“O7” “C7”

s b ℓ+ ℓ−

“O9”, “O10” “C9”, “C10”

◮ “Effective operators” Oi ◮ “Wilson Coefficients” Ci

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

◮ Have an effective Hamiltonian =

⇒ can calculate things Heff = −4GF √ 2 e2 16π2 VtbV ∗

ts

  • i=7,9,10
  • CiOi + C′

iO′ i

  • + h.c.

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

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SLIDE 17

The operator-product expansion

Or: how to be model independent

s b γ

“O7” “C7”

s b ℓ+ ℓ−

“O9”, “O10” “C9”, “C10”

◮ “Effective operators” Oi ◮ “Wilson Coefficients” Ci

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

◮ Have an effective Hamiltonian =

⇒ can calculate things Heff = −4GF √ 2 e2 16π2 VtbV ∗

ts

  • i=7,9,10
  • CiOi + C′

iO′ i

  • + h.c.

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

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SLIDE 18

A word on QCD

Enter form factor uncertainty

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

ˆ O = f (Ci, {form factors})

s b µ− µ+ W − Z0, γ ¯ d ¯ d

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

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SLIDE 19

A word on QCD

Enter form factor uncertainty

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

ˆ O = f (Ci, {form factors})

s b µ− µ+ W − Z0, γ ¯ d ¯ d

s b µ− µ+ ¯ d ¯ d

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

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SLIDE 20

O7

b → sℓℓ

cos θK q2 V (q2) T3(q2)

AL

A2(q2)

ξ⊥

C9

S6

P ′

5

C7

CNP

9

AFB

|AR

|2

P ′

4

b → sγ

Jc

1

ξ

¯ Js

2

Nomenclature

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SLIDE 21

O7

b → sℓℓ

cos θK q2 V (q2) T3(q2)

AL

A2(q2)

ξ⊥

C9

S6

P ′

5

C7

CNP

9

AFB

|AR

|2

P ′

4

b → sγ

Jc

1

ξ

¯ Js

2

Nomenclature

q2 = m2

ℓℓ

Squared dilepton invariant mass

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SLIDE 22

Observables, observables, observables

◮ Need to find measurable quantities that...

◮ ...are sensitive to the Wilson Coefficients ◮ ...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−

τB0 τB+ B

  • B± → K(∗)±µ+µ−

B

  • B0 → K(∗)0µ+µ−
  • +

τB0 τB+ B

  • B± → K(∗)±µ+µ−
  • S.Cunliffe (Imperial)

FFP14 b → sℓℓ Theory 10/21

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SLIDE 23

Why study rare decays? The LHCb detector b→ sℓℓ Theory The operator-product expansion Observables, observables, observables Isospin asymmetry of B → K(∗)µ+µ− Angular analysis of B0 → K∗0µ+µ− Observables from the angular distribution LHCb measurement Interpretations Global fits Form factor uncertainties Lepton universality in B± → K±ℓ+ℓ− Something strange from charm Conclusions

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SLIDE 24

Isospin asymmetry of B → K(∗)µ+µ−

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

◮ Measure asymmetry in rate

between neutral and charged modes

◮ B0 → K∗0(→ K±π∓)µ+µ− ◮ B± → K∗±(→ K0 Sπ±)µ+µ− ◮ B0 → K0 Sµ+µ− ◮ B± → K±µ+µ−

◮ Asymmetry v.close to zero in SM ◮ Experimental challenge:

◮ K0

S → π+π− reconstruction ◮ Normalise to

B → J/ψ (→ µ+µ−)K(∗)

◮ 3 fb−1 2011+2012 data

]

2

c ) [MeV/

µ

+

µ

π

+

K ( m

5200 5400 5600

)

2

c Candidates / ( 10 MeV/

200 400

LHCb

µ

+

µ

*0

K → B

]

2

c ) [MeV/

µ

+

µ

+

π

S

K ( m

5200 5400 5600

)

2

c Candidates / ( 10 MeV/

20 40 60

LHCb

µ

+

µ

*+

K →

+

B

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

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SLIDE 25

Isospin asymmetry of B → K(∗)µ+µ−

AI = B

  • B0 → K(∗)0µ+µ−

τB0 τB+ B

  • B± → K(∗)±µ+µ−

B

  • B0 → K(∗)0µ+µ−
  • +

τB0 τB+ B

  • B± → K(∗)±µ+µ−
  • ]

4

c /

2

[GeV

2

q

5 10 15 20 I

A

  • 1
  • 0.5

0.5 1

LHCb

µ

+

µ K → B

*

]

4

c /

2

[GeV

2

q

5 10 15 20 I

A

  • 1
  • 0.5

0.5 1

LHCb

µ

+

µ K → B

Consistent with SM. (AI ≈ 0)

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

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SLIDE 26

Why study rare decays? The LHCb detector b→ sℓℓ Theory The operator-product expansion Observables, observables, observables Isospin asymmetry of B → K(∗)µ+µ− Angular analysis of B0 → K∗0µ+µ− Observables from the angular distribution LHCb measurement Interpretations Global fits Form factor uncertainties Lepton universality in B± → K±ℓ+ℓ− Something strange from charm Conclusions

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SLIDE 27

Observables from the angular distribtion

For B0 → K∗(892)0(→ K±π∓)µ+µ− decays...

◮ P → V V ′ (pseudoscalar to vector-vector) ◮ Vector K∗(892) =

⇒ angular distribution, as well as rate, is interesting

B0 K* 0 K+

π - μ - μ+

θK θℓ φ

◮ 3 angles, and q2

  • θK, θℓ, φ, q2

◮ Angular distribution −

→ Sets of observables:

  • FL, AFB, A2

T, S9

  • {P ′

4, P ′ 5, P ′ 6, P ′ 8} ◮ ...Clever ratios of angular terms

S.Cunliffe (Imperial) FFP14 Angular analysis of B0 → K∗0µ+µ− 13/21

slide-28
SLIDE 28

Observables from the angular distribtion

For B0 → K∗(892)0(→ K±π∓)µ+µ− decays...

◮ P → V V ′ (pseudoscalar to vector-vector) ◮ Vector K∗(892) =

⇒ angular distribution, as well as rate, is interesting

B0 K* 0 K+

π - μ - μ+

θK θℓ φ

◮ 3 angles, and q2

  • θK, θℓ, φ, q2

◮ Angular distribution −

→ Sets of observables:

  • FL, AFB, A2

T, S9

  • {P ′

4, P ′ 5, P ′ 6, P ′ 8} ◮ ...Clever ratios of angular terms

S.Cunliffe (Imperial) FFP14 Angular analysis of B0 → K∗0µ+µ− 13/21

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SLIDE 29

Angular analysis of B0 → K∗0µ+µ−

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

◮ Fit a reduced angular distribution ◮ 3D fit, binned in q2

  • P ′

4, P ′ 5, P ′ 6, P ′ 8

  • ◮ Correct for detector acceptance

◮ Observe local 3.7σ deviation

from SM [JHEP 1305 (2013) 137]

◮ Prob. for 24 independent

  • bservations (4P’s × 6q2 bins) is

0.5%

◮ 1 fb−1 2011 data ]

4

c /

2

[GeV

2

q

5 10 15 20

'

4

P

  • 1
  • 0.8
  • 0.6
  • 0.4
  • 0.2

0.2 0.4 0.6 0.8 1

SM Predictions Data

LHCb

]

4

c /

2

[GeV

2

q

5 10 15 20

'

5

P

  • 1
  • 0.8
  • 0.6
  • 0.4
  • 0.2

0.2 0.4 0.6 0.8 1

SM Predictions Data

LHCb

S.Cunliffe (Imperial) FFP14 Angular analysis of B0 → K∗0µ+µ− 14/21

slide-30
SLIDE 30

Why study rare decays? The LHCb detector b→ sℓℓ Theory The operator-product expansion Observables, observables, observables Isospin asymmetry of B → K(∗)µ+µ− Angular analysis of B0 → K∗0µ+µ− Observables from the angular distribution LHCb measurement Interpretations Global fits Form factor uncertainties Lepton universality in B± → K±ℓ+ℓ− Something strange from charm Conclusions

slide-31
SLIDE 31

Global fits

P ′

5 ⇒ tension in C9

Descotes-Genon, Matias & Virto

[Phys. Rev. D 88, 074002 (2013)] ◮ Global fit including {P ′ 4, P ′ 5, P ′ 6, P ′ 8} ◮ Fit includes b→ sℓℓ and b→ sγ inputs ◮ 4.5σ discrepancy from SM point ◮ Favours CNP 9

≈ −1.5

68.3 C.L 95.5 C.L 99.7 C.L Includes Low Recoil data Only 1,6 bins SM

0.15 0.10 0.05 0.00 0.05 0.10 0.15 4 2 2 4 C7

NP

C9

NP

Altmannshofer & Straub

[Eur. Phys. J. C (2013) 73: 2646] ◮ 3σ discrepancy ◮ Differences:

◮ Definitions of observables ◮ Different q2 ranges ◮ Theory assumptions

◮ Best fit is modified C9 ◮ Data described by additional Z′ at ∼ 7TeV ◮ Hard to reconcile with MSSM

3 2 1 1 2 3 3 2 1 1 2 3

ReC9

NP

ReC9

'

FL S4 S5 AFB BK ΜΜ

S.Cunliffe (Imperial) FFP14 Interpretations 15/21

slide-32
SLIDE 32

A hint of new physics?

Contributions from new Z′ vector?

Descotes-Genon, et al.

[JHEP 1305 (2013) 137)] ◮ Originally motivated {Pi}

  • bservables

◮ Simplification (assumption) in

choice of form factors

]

4

c /

2

[GeV

2

q

5 10 15 20

'

5

P

  • 1
  • 0.8
  • 0.6
  • 0.4
  • 0.2

0.2 0.4 0.6 0.8 1

SM Predictions Data

LHCb

3.7σ J¨ ager & Camlich

[JHEP 1305 (2013) 043] ◮ Uncertainty due to simplified

choice of form factors (factorisable corrections are underestimated)

S.Cunliffe (Imperial) FFP14 Interpretations 16/21

slide-33
SLIDE 33

A hint of new physics?

...or underestimated errors

Descotes-Genon, et al.

[JHEP 1305 (2013) 137)] ◮ Originally motivated {Pi}

  • bservables

◮ Simplification (assumption) in

choice of form factors

]

4

c /

2

[GeV

2

q

5 10 15 20

'

5

P

  • 1
  • 0.8
  • 0.6
  • 0.4
  • 0.2

0.2 0.4 0.6 0.8 1

SM Predictions Data

LHCb

3.7σ J¨ ager & Camlich

[JHEP 1305 (2013) 043] ◮ Uncertainty due to simplified

choice of form factors (factorisable corrections are underestimated)

]

4

c /

2

[GeV

2

q

5 10 15 20

'

5

P

  • 1

1

SM arXiv:1303.5794 SM arXiv:1212.2263

  • 1

LHCb 1fb

ΑΒ;696∀;4∀&3.<∀Χ8D7.∀Ε;∗.∀?∀//<∀−0∃−−!∀Φ!−,#Γ<∀Η9∋Ι&6∀

S.Cunliffe (Imperial) FFP14 Interpretations 16/21

slide-34
SLIDE 34

Why study rare decays? The LHCb detector b→ sℓℓ Theory The operator-product expansion Observables, observables, observables Isospin asymmetry of B → K(∗)µ+µ− Angular analysis of B0 → K∗0µ+µ− Observables from the angular distribution LHCb measurement Interpretations Global fits Form factor uncertainties Lepton universality in B± → K±ℓ+ℓ− Something strange from charm Conclusions

slide-35
SLIDE 35

Lepton universality in B± → K±ℓ+ℓ−

[arXiv:1406.6482] submitted: Phys.Rev.Lett RK = B

  • B± → K±µ+µ−

B[B± → K±e+e−]

◮ If a Z′ is responsible for P ′ 5 does it

couple equally to lepton flavours?

◮ Altmannshofer et al.

[Phys. Rev. D89 (2014) 095033]

◮ Kr¨

uger & Hiller

[Phys.Rev. D69 (2004) 074020] ◮ Experimental challenge:

◮ Selection of B± → K±e+e− ◮ Bremsstrahlung → q2 movement

◮ Correct for bremsstrahlung with

calorimeter photons

◮ Migration in q2 corrected with

simulation

◮ 3 fb−1 2011+2012 data

]

2

c ) [MeV/

e

+

e

+

K ( m

5000 5200 5400 5600

)

2

c Candidates / ( 40 MeV/

5 10

3

10 × LHCb (a)

B± → J/ ψ K±

]

2

c ) [MeV/

e

+

e

+

K ( m

5000 5200 5400 5600

)

2

c Candidates / ( 40 MeV/

10 20 30 40 LHCb (d)

B± → K±e+e− S.Cunliffe (Imperial) FFP14 Lepton universality in B± → K±ℓ+ℓ− 17/21

slide-36
SLIDE 36

Lepton universality in B± → K±ℓ+ℓ−

◮ Experimentally, use double ratio with B± → J/ψ K± decays

◮ Cancels systematic biases

RK = NK±µ+µ− NJ/ψ (µ+µ−)K± NJ/ψ (e+e−)K± NK±e+e− × ǫJ/ψ (µ+µ−)K± ǫK±µ+µ− ǫK±e+e− ǫJ/ψ (e+e−)K±

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

◮ RK = 1.000 in SM (argue about

the 4th s.f.)

◮ SM Higgs v.suppressed

◮ LHCb measures

RK = 0.745+0.090

−0.074 ± 0.036

◮ In range q2 ∈ [1, 6] GeV2/c4 ◮ Only agrees with SM within 2.6σ

]

4

c /

2

[GeV

2

q

5 10 15 20

K

R

0.5 1 1.5 2 SM

LHCb LHCb

LHCb BaBar Belle

BaBar:

[Phys. Rev. D86 (2012) 032012]

Belle:

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

S.Cunliffe (Imperial) FFP14 Lepton universality in B± → K±ℓ+ℓ− 18/21

slide-37
SLIDE 37

Why study rare decays? The LHCb detector b→ sℓℓ Theory The operator-product expansion Observables, observables, observables Isospin asymmetry of B → K(∗)µ+µ− Angular analysis of B0 → K∗0µ+µ− Observables from the angular distribution LHCb measurement Interpretations Global fits Form factor uncertainties Lepton universality in B± → K±ℓ+ℓ− Something strange from charm Conclusions

slide-38
SLIDE 38

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) χ

2/d.o.f=1.05

BESII e+e− → hadrons/e+e− → µ+µ−

0.5 1 1.5 2 2.5 3 3.5 3.6 3.8 4 4.2 4.4 4.6

dBr d√ q2 [B+ → K+µµ]/10−7GeV−1

  • q2/GeV

Ψ(3770) Ψ(4040) Ψ(4160) Ψ(4400) a) afac b) ηcafac c) ρr ∈ R d) ρr ∈ C LHCb Ψ(4415) Ψ(2S)

LHCb data: B± → K±µ+µ−, L&Z fits

Lyon & Zwicky

[arXiv:1406.0566] ◮ Fit BESII and LHCb data ◮ Necessary to add in large corrections (fudge factors) to get good fit ◮ Are we underestimating the non-factorisable effects in Ceff 9 ?

◮ Could explain P ′

5 effect

◮ And/or motivate new physics studies in b→ ccs operators S.Cunliffe (Imperial) FFP14 Something strange from charm 19/21

slide-39
SLIDE 39

Something strange from charm (loops)

ℓ ¯ cc O1,2 ℓ ℓ γ(q) b s (a) (b) ℓ O1,2 ℓ ℓ γ(q) b s ℓ

J/Ψ, Ψ′..

O1,2 ℓ ℓ γ(q) b s ℓ O1,2 ℓ ℓ γ(q) b s ℓ O1,2 b s ¯ cc O1,2 b s OG b s g ℓ ℓ γ(q) ℓ ℓ (c)

◮ Massively underestimated terms like (a) at low q2 ◮ The green gluons can’t account for this

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

slide-40
SLIDE 40

Why study rare decays? The LHCb detector b→ sℓℓ Theory The operator-product expansion Observables, observables, observables Isospin asymmetry of B → K(∗)µ+µ− Angular analysis of B0 → K∗0µ+µ− Observables from the angular distribution LHCb measurement Interpretations Global fits Form factor uncertainties Lepton universality in B± → K±ℓ+ℓ− Something strange from charm Conclusions

slide-41
SLIDE 41

Conclusions

◮ FCNC processes probe higher mass scales for NP

◮ Formalism gives model-independence ◮ Observables!

◮ Interesting results in b→ sℓℓ processes

◮ Isospin asymmetry in B → K(∗)µ+µ− ◮ Angular analyses of B0 → K∗0µ+µ− ◮ Lepton universality in B± → K±ℓ+ℓ−

◮ Interest from our theory/phenomenology friends ◮ LHCb data-taking in 2015... ◮ Belle-II physics runs late 2016...

S.Cunliffe (Imperial) FFP14 Conclusions 21/21

slide-42
SLIDE 42

[Backup Slides]

slide-43
SLIDE 43

The actual definitions of the Wilson Operators

Heff = −4GF √ 2 e2 16π2 VtbV ∗

ts

  • i=7,9,10
  • CiOi + C′

iO′ i

  • + h.c.

O7 = e g2 ¯ mb(¯ sσµνPRb)F µν, O′

7 = e

g2 ¯ mb(¯ sσµνPLb)F µν, O9 = e2 g2 (¯ sγµPLb)(¯ ℓγµℓ), O′

9 = e2

g2 (¯ sγµPRb)(¯ ℓγµℓ), O10 = e2 g2 (¯ sγµPLb)(¯ ℓγµγ5ℓ), O′

10 = e2

g2 (¯ sγµPRb)(¯ ℓγµγ5ℓ),

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slide-44
SLIDE 44

The actual definitions of the Wilson Operators

Ci = CSM

i

+ CNP

i

, C′

i = C′ SM i

+ C′ NP

i

.

◮ ∄ right-handed interactions i = 9, 10 operators in SM

C′ SM

9,10 = 0 ◮ ∃ helicity-suppressed right-handed SM contributions to O′ 7 so

C′

7 = ms

mb (CSM

7

+ CNP

7

) + C′ NP

7

.

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SLIDE 45

Angular distribution of B0 → K∗0µ+µ−

The distribution of for vector K∗0(892)

d4Γ d cos θKd cos θldφdq2 = 9 32π

  • Js

1 sin2 θK + Jc 1 cos2 θK

+ (Js

2 sin2 θK + Jc 2 cos2 θK) cos 2θℓ

+ J3 sin2 θK sin2 θℓ cos 2φ + J4 sin 2θK sin 2θℓ cos φ + J5 sin 2θK sin θℓ cos φ + J6 sin2 θK cos θℓ + J7 sin 2θK sin θℓ sin φ + J8 sin 2θK sin 2θℓ sin φ + J9 sin2 θK sin2 θℓ sin 2φ

  • S.Cunliffe (Imperial)

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slide-46
SLIDE 46

Angular distribution of B0 → K∗0µ+µ−

The principle moments

J1s = 3 4

  • |AL

⊥|2 + |AL |2 + |AR ⊥|2 + |AR |2

J1c = |AL

0 |2 + |AR 0 |2

J2s = 1 4

  • |AL

⊥|2 + |AL |2 + |AR ⊥|2 + |AR |2

J2c = −

  • |AL

0 |2 + |AR 0 |2

J3 = 1 2

  • |AL

⊥|2 − |AL |2 + |AR ⊥|2 − |AR |2

J4 = 1 √ 2

  • ℜ(AL

0 AL∗

  • + AR

0 AR∗ )

  • J5 =

√ 2

  • ℜ(AL

0 AL∗ ⊥ − AR 0 AR∗ ⊥ )

  • J6 = 2
  • ℜ(AL

AL∗ ⊥ − AR AR∗ ⊥ )

  • J7 =

√ 2

  • ℑ(AL

0 AL∗

  • − AR

0 AR∗ )

  • J8 =

1 √ 2

  • ℑ(AL

0 AL∗ ⊥ − AR 0 AR∗ ⊥ )

  • J9 = ℑ(AL∗

AL ⊥ + AR∗ AR ⊥).

(1)

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SLIDE 47

The Amplitudes

Calculated 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(m2

B − m2 K∗)

(Ceff

9

− Ceff′

9

) ∓ (Ceff

10 − Ceff′ 10 )

  • A1(q2)

mB − mK∗ + 2mb q2 (Ceff

7

− Ceff′

7

)T2(q2)

  • ,

AL,R = − N 2mK∗∗

  • q2

(Ceff

9

− Ceff′

9

) ∓ (Ceff

10 − Ceff′ 10 )

  • ×
  • (m2

B − m2 K∗∗ − q2)(mB + mK∗∗)A1(q2) − λ

A2(q2) mB + mK∗∗

  • + 2mb(Ceff

7

− Ceff′

7

)

  • (m2

B + 3m2 K∗∗ − q2)T2(q2) −

λ m2

B − m2 K∗∗

T3(q2)

  • ,

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SLIDE 48

The Amplitudes

Calculated in the effective field theory

...where N = VtbV ∗

ts

  • G2

F α2

3 · 210π5m3

B

q2λ1/2βµ 1/2 , with λ = m4

B + m4 K∗ + q4 − 2(m2 Bm2 K∗ + m2 K∗q2 + m2 Bq2) and

βµ =

  • 1 − 4m2

µ/q2.

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SLIDE 49

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

  • ℜ(AL

0 AL∗ ⊥ − AR 0 AR∗ ⊥ )

  • FL(1 − FL)

◮ The asymmetry of the cross term between the longitudinal and

perpendicularly polarised amplitudes.

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