What B physics can say about BSM models
Anton Poluektov
The University of Warwick, UK
Budker Institute of Nuclear Physics, Novosibirsk, Russia
12 April 2016
11th Franco-Italian meeting on B physics,
Paris, LPNHE, 11 – 13 April 2016
Thanks to C. Langenbruch and G. Cowan for donating many slides
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
1/36
Standard Model
The Standard Model A was released
in 1908 with its characteristic
Columbia type speed control.
Standard was still in business as late
as 1920, selling model A’s even
though an internal horn model B was
introduced in 1911. The Standard
Model B was not to replace the
model A, but merely expand the
model range. The model A has a red
iridescent horn. The model A, like
the model AA has a large spindle,
and will only play ”Standard” records.
How Standard Model works, YouTube demonstration
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
2/36
Introduction
In general, we search for NP indirectly in processes where SM contributions are
suppressed, and so, small NP effects can become visible (or even dominant).
Phenomenologically, we can classify potential NP contributions as
∆F = 1 (B decays)
Loop suppression (NP can enter through trees, e.g. FCNC)
Helicity suppression (Vector-mediated SM transitions are small compared to
(pseudo)scalar-mediated NP).
∆F = 2 (neutral B mixing)
2nd order weak transition in SM, can be enhanced by NP
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
3/36
Introduction
In general, we search for NP indirectly in processes where SM contributions are
suppressed, and so, small NP effects can become visible (or even dominant).
Phenomenologically, we can classify potential NP contributions as
∆F = 1 (B decays)
Loop suppression (NP can enter through trees, e.g. FCNC)
Helicity suppression (Vector-mediated SM transitions are small compared to
(pseudo)scalar-mediated NP).
∆F = 2 (neutral B mixing)
2nd order weak transition in SM, can be enhanced by NP
Usually, after excitement of first data, everything is perfectly consistent with SM,
so we enter the regime of precision measurement (search for NP as a small
correction to SM)
Variation: after exciting 3-4σ tension, we enter the regime of precision
measurement and the tension vanishes
Experimental and theoretical challenges related to precision measurements
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
3/36
Introduction
An incomplete selection of NP-sensitive measurements
Very rare decays (Bs0 → µ+ µ− )
b → s penguins (B 0 → K ∗ µ+ µ− )
Radiative b → sγ decays (B 0 → K ∗ γ)
Radiative b → sγγ decays (B(s) → γγ)
Fully leptonic decays (B → τ ντ )
Direct CP violation
B(s) mixing (B 0 → J/ψ KS0 , Bs0 → J/ψ φ)
Flavour-violating decays (τ → 3µ)
Lepton (non-)universality (RK , B → D (∗)τ ν )
Anton Poluektov
B physics and BSM models
Covered this morning
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
4/36
Effective field theory
Anton Poluektov
Observable 1
Model 1
Observable 2
Model 2
Observable 3
Model 3
Observable N
Model M
Experiment
Theory
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
5/36
Effective field theory
Observable 1
Model 1
Observable 2
Model 2
Observable 3
Wilson
coeffs
Model 3
Observable N
Model M
Experiment
Theory
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
5/36
Effective field theory
Model-independent description in effective field theory
X
4GF
Ci Oi + Ci0 Oi0
Heff = − √ Vtb Vts∗
|{z} | {z }
2
i
ms
suppressed
Left-handed Right-handed, m
b
(0)
Wilson coefficients Ci
b
(0)
encode short-distance physics, Oi
s
(0)
O7 photon penguin
b
γ
`
s
b
`
`
(0)
Anton Poluektov
B → µµ
b → s``
3
(0)
O9 vector coupling
(0)
O10 axialvector coupling
OS,P (pseudo)scalar penguin
s
b → sγ
3
corr. operators
3
3
3
3
`
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
6/36
Very rare decays: Bs0 → µ+ µ−
NP
SM
µ+
b̄
µ+
b̄
¯t̃
ū, c̄, t̄
s̄
γ, Z
Bs0
Bs0
W
χ̃±
H 0 , A0
u, c, t
µ−
s
Weak suppression (2nd order)
Helicity suppression
Anton Poluektov
B physics and BSM models
s
µ−
(MSSM contribution)
Extremely sensitive to scalar and
pseudoscalar NP operators
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
7/36
Very rare decays: Bs0 → µ+ µ−
Combined analysis of LHCb and CMS Run I data
[Nature 522 (2015) 68-72]
Weighted candidates per 40 MeV/c2
CMS and LHCb (LHC run I)
60
Data
Signal and background
B0s→ µ+µ−
B0→ µ+µ−
Combinatorial background
Semi-leptonic background
Peaking background
50
40
30
20
10
0
5000
5200
5400
5600
5800
mµ+µ− [MeV/ c2]
First obs. of Bs0 → µ+ µ− with 6.2 σ significance (expected 7.2 σ)
+0.7
B(Bs0 → µ+ µ− ) = (2.8−0.6
) × 10−9
compatible with SM at 1.2 σ
First evidence for B 0 → µ+ µ− with 3.0 σ significance (expected 0.8 σ)
+1.6
) × 10−10
compatible with SM at 2.2 σ
B(B 0 → µ+ µ− ) = (3.9−1.4
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
8/36
Very rare decays: Bs0 → µ+ µ−
[Nature 522 (2015) 68-72]
CMS and LHCb (LHC run I)
40
1−
1−
−7
×10
6.3
a
0
0
10
b
−2ΔlnL
SM
0.1
20
0
0
2
4
6
8
B(B 0s → µ + µ −) [10−9]
10
0.3
0.2
SM
30
−5
7%
0.4
5%
68.2
0.5
3%
99.7
0.6
×10
5.7
0.7
−9
1−
0
2×1
0.8
−2ΔlnL
0.9
95.4
B(B0 → µ + µ −) [10−9]
Combined analysis of LHCb and CMS Run I data
8
SM
6
4
2
1
2
3
4
5
6
7
8
9
B(Bs0 → µ + µ −) [10−9]
c0
0
0.2
0.4
0.6
0.8
B(B 0 → µ + µ −) [10−9]
First obs. of Bs0 → µ+ µ− with 6.2 σ significance (expected 7.2 σ)
+0.7
B(Bs0 → µ+ µ− ) = (2.8−0.6
) × 10−9
compatible with SM at 1.2 σ
First evidence for B 0 → µ+ µ− with 3.0 σ significance (expected 0.8 σ)
+1.6
) × 10−10
compatible with SM at 2.2 σ
B(B 0 → µ+ µ− ) = (3.9−1.4
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
8/36
Very rare decays: Bs0 → µ+ µ−
Recent news from ATLAS collaboration
[Moriond EW 2016 preliminary]
+1.1
B(Bs0 → µ+ µ− ) = (0.9−0.8
) × 10−9 (< 3.0 × 10−9 at 95% CL)
0
+ −
B(B → µ µ ) < 4.2 × 10−9 at 95% CL
Compatibiltiy with SM for simultaneous fit: 2.0σ
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
9/36
Very rare decays: Bs0 → µ+ µ−
2.0
1.5
MSSM-RVV2
1.0
V
MF
SM4
M
-AK
SM
MS
0.5
0.0
[D. Straub, arXiv:1205.6094]
MSSM-LL
MSSM-AC
SM
0
10
20
30
40
50
B(s) → µ+ µ− exclude a huge parameter region of MSSM and 4-gen models.
[G. Hou, arXiv:1307.2448]
Fourth generation can accommodate enhanced B(B 0 → µ+ µ− ) if it’s confirmed.
In addition, reduces some tensions in CKM measurements, but needs a rather
conspirological explanation of SM Higgs couplings.
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
10/36
Very rare decays: Bs0 → µ+ µ−
2.0
1.5
[D. Straub, arXiv:1205.6094]
MSSM-LL
Vote?
MSSM-RVV2
1.0
V
MF
SM4
−
“supersymmetry is dead”
%
68.27
%
95.45
0.5
SM
0.0
0
Environ 1 560 résultats
M
-AK
SM
MS
“supersymmetry is not dead”
MSSM-AC
10 résultats
SM
10
20
30
40
50
B(s) → µ+ µ− exclude a huge parameter region of MSSM and 4-gen models.
[G. Hou, arXiv:1307.2448]
Fourth generation can accommodate enhanced B(B 0 → µ+ µ− ) if it’s confirmed.
In addition, reduces some tensions in CKM measurements, but needs a rather
conspirological explanation of SM Higgs couplings.
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
10/36
“Golden mode” B 0 → K ∗0 [→ K + π − ]µ+ µ−
d
B0
K ∗0
t̄
s̄
b̄
K*
K*
z
B
W
Figure 1. Kin
B̄d0 → K̄ ∗0 (→ K − π
¯
i) the (``)-invaria
ii) the angle θ` be
¯ center
in the (``)
the angle θK ∗ bet
the (K − π + ) c.m.
between the two d
by the 3-momenta
¯
(``)-systems,
respe
K
d
+
Z 0, γ
µ−
+
+
µ+
2
~ = (θ , θK , φ) and q 2 = mµµ
Decay fully described by three helicity angles
Ω
V is assumed to`be on-shell
in the narrow-resonance approximation w
4
0
∗0
− +
¯
of kinematic variables to four . Using B̄d → K̄ (→ K π ) + `` for il
d3 (Γ + Γ̄)
1
9 3
2
as depicted
(1 − FL ) sin2 θK +chosen
FL cos
θK + 14in(1figure
− FL1.) sin2 θK cos 2θ`
=
4
2
~
32π
d(Γ + Γ̄)/dq
dΩ
The differential decay rate, after summing over lepton spins, factor
− FL cos2 θK cos 2θ` + S3 sin28πθK sin2 θ`dcos
4 Γ 2φ
dq 22θ
d cos
θ` dθcos
θK ∗ φ
dφ
+ S4 sin 2θK sin 2θ` cos φ + S53sin
K sin
` cos
= J1s sin2 θK ∗ + J1c cos2 θK ∗ + (J2s sin2 θK ∗
2
+J3 sin θK ∗ sin2 θ` cos 2φ + J4 sin 2θK ∗ sin 2θ` cos φ + J
+ 43 AFB sin2 θK cos θ` + S7 sin 2θK sin θ` sin φ
+ S8 sin 2θK sin 2θ` sin φ + S9 sin2 θK sin2 θ` sin 2φ
+(J6s sin2 θK ∗ + J6c cos2 θK ∗ ) cos θ` + J
+J8 sin 2θK ∗ sin 2θ` sin φ + J9 s
FL , AFB , Si combinations of K ∗0 spin amplitudes 2
j 2
5
(0)
(0)that is,
(0)into q -dependent observables Ji (q ) and the dependence o
depending on Wilson coefficients C7 , C9 φ., CNo10additional
and form
angularfactors
dependencies can be induced by any exten
basis [11] as found by [12, 13]. The following simplifications arise in the
Perform ratios of angular observables where
form factors cancel at leading order
J1c = −J2c and J6c = 0.
Descotes-Genon et al.,
Example: P50 = √ S5
[S.JHEP,
] The differential decay rate d4Γ̄ of the CP-conjugated decay Bd0 →
05 (2013) 137
FL (1−FL )
obtained through the following replacements
Relative sign between B 0 and B 0 → access to CP
asymmetries
AW ],
Jj
→ J¯j
[δW → −δ3,...,9
1,2,3,4,7
Anton Poluektov
B physics and BSM models
1,2,3,4,7
j
j
J5,6,8,9
→ − J¯5,6,8,9
[δW
due to ` ↔ `¯ ⇒ θ → θ − π and φ → −φ. The CP-violating (weak)
ph
11/36
`
` 11 – 13 April 2016
11th Franco-Italian meeting on B physics,
q2 [GeV2/ c4]
B 0 → K ∗0 µ+ µ− selection
[LHCb, JHEP 02 (2016) 104]
20
LHCb
18
104
16
14
103
12
10
102
8
6
10
4
2
0
5.2
5.3
5.4
5.5
5.6
m(K +π -µ +µ -)
5.7
1
[GeV/c2]
BDT to suppress combinatorial background
Input variables: PID, kinematic and geometric quantities, isolation variables
Veto of B 0 → J/ψ K ∗0 and B 0 → ψ(2S)K ∗0 (important control decays)
and peaking backgrounds using kinematic variables and PID
Signal clearly visible as vertical band after the full selection
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
12/36
1.1 < q2 < 6.0 GeV2/c4
60
40
LHCb
1.1 < q2 < 6.0 GeV2/c4
100
50
20
0
0.5
0
-1
1
cos θ l
-0.5
LHCb
1.1 < q2 < 6.0 GeV2/c4
100
50
0
5200
5400
5600
m(K +π −µ +µ −) [MeV/c2]
0
Candidates / 10 MeV/c2
-0.5
Candidates / 5.3 MeV/c2
0
-1
0.5
1.1 < q2 < 6.0 GeV2/c4
60
40
20
0
1
LHCb
80
cos θ K
-2
LHCb
150
1.1 < q2 < 6.0 GeV2/c4
100
50
0
0.8
0.85
0.9
0.95
m(K +π −) [GeV/c2]
0
2
φ [rad]
[LHCb, JHEP 02 (2016) 104]
LHCb
80
Candidates / 0.1 π rad
Candidates / 0.1
Candidates / 0.1
B 0 → K ∗0 µ+ µ− likelihood projections [1.1, 6.0] GeV2/c 4
Use B 0 → J/ψ K ∗ as control channel
Efficiency corrected distributions show good agreement
with overlaid projections of the probability density function
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
13/36
1
S3
FL
B 0 → K ∗0 µ+ µ− Results: FL , S3 , S4 , S5
0.5
LHCb
0.8
0.6
LHCb
SM from ABSZ
SM from ABSZ
[1503.05534][1411.3161]
[1503.05534][1411.3161]
0
0.4
0.2
-0.5
5
10
15
0
5
10
15
q2 [GeV2/ c4]
S5
S4
q2 [GeV2/ c4]
0.5
0.5
LHCb
LHCb
SM from ABSZ
SM from ABSZ
[1503.05534][1411.3161]
[1503.05534][1411.3161]
0
0
-0.5
0
-0.5
5
10
15
0
5
10
q2 [GeV2/ c4]
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
[LHCb, JHEP 02 (2016) 104]
0
0
15
q2 [GeV2/ c4]
14/36
S7
0.5
0.5
LHCb
0
0
LHCb
prelim.
SM from ABSZ
-0.5
0
-0.5
[1503.05534][1411.3161]
5
10
15
0
5
10
15
q2 [GeV2/ c4]
S9
S8
q2 [GeV2/ c4]
0.5
LHCb
0.5
LHCb
prelim.
0
-0.5
5
10
15
0
5
10
q2 [GeV2/ c4]
Anton Poluektov
prelim.
0
-0.5
0
prelim.
[LHCb, JHEP 02 (2016) 104]
A FB
B 0 → K ∗0 µ+ µ− Results: AFB , S7 , S8 , S9
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
15
q2 [GeV2/ c4]
15/36
B 0 → K ∗0 µ+ µ− : P50
5
P'
[LHCb, JHEP 02 (2016) 104]
1
LHCb
0.5
SM from DHMV
[1407.8526]
0
-0.5
-1
0
5
10
15
q2 [GeV2/ c4]
[4.0, 6.0] and [6.0, 8.0] GeV2/c 4 local deviations of 2.8σ and 3.0σ
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
16/36
B 0 → K ∗0 µ+ µ− : P50
5
P'
[LHCb, JHEP 02 (2016) 104]
1
LHCb
0.5
SM from DHMV
[1407.8526]
0
-0.5
-1
0
5
10
15
q2 [GeV2/ c4]
[4.0, 6.0] and [6.0, 8.0] GeV2/c 4 local deviations of 2.8σ and 3.0σ
Tension seen in P50 in [PRL 111, 191801 (2013)] confirmed
Compatible with 1 fb−1 measurement
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
16/36
B 0 → K ∗0 µ+ µ− : P50
5
P'
[LHCb, JHEP 02 (2016) 104]
2
LHCb
1
SM from DHMV
Likelihood fit
Method of moments
0
-1
-2
0
5
10
15
q2 [GeV2/ c4]
[4.0, 6.0] and [6.0, 8.0] GeV2/c 4 local deviations of 2.8σ and 3.0σ
Tension seen in P50 in [PRL 111, 191801 (2013)] confirmed
Compatible with 1 fb−1 measurement
Moments analysis: 10-30% less sensitive than Maximum Likelihood
2 4
Beaujean et al.,
fit [F.
wide q 2 bins
PRD 91 (2015) 114012] but allows narrow 1 GeV /c
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
16/36
15
10
5
LHCb
0
3
3.5
4
[LHCb, JHEP 02 (2016) 104]
SM
∆χ 2
B 0 → K ∗0 µ+ µ− : Compatibility with the SM
4.5
Re (C9)
Perform χ2 fit of measured Si observables using [EOS] software
Beaujean et al.,
Varying Re(C9 ) and incl. nuisances according [F.
EPJC 74 (2014) 2897]
∆Re(C9 ) = −1.04 ± 0.25 with global significance of 3.4 σ
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
17/36
Bs0
s
φ
t̄
s̄
b̄
W+
µ−
Z 0, γ
µ
+
18
16
14
12
10
8
6
4
2
0
103
102
10
LHCb
5.3
5.4
5.5
[LHCb, JHEP 09 (2015) 179]
s
q2 [GeV2/ c4]
The rare decay Bs0 → φ[→ K + K − ]µ+ µ−
1
−
m(K +K µ +µ −) [GeV/c2]
Dominant b → sµ+ µ− decay for Bs0 , analogous to B 0 → K ∗0 µ+ µ−
K + K − µ+ µ− final state not self-tagging
→ reduced number of angular observables: FL , S3,4,7 , A5,6,8,9
Signal yield lower due to
fs
fd
∼ 14 ,
B(φ→K + K − )
B(K ∗0→K + π − )
=
3
4
Clean selection due to narrow φ resonance, S-wave negligible
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
18/36
9
LHCb
8
7
6
5
4
3
SM pred.
SM (wide)
SM LQCD
Data
Data (wide)
2
1
0
5
10
[LHCb, JHEP 09 (2015) 179]
dB(B0s → φ µ µ )/dq2 [10-8GeV-2c4]
Bs0 → φµ+ µ− differential branching fraction
15
q2 [GeV2/ c4]
In 1 < q 2 < 6 GeV2/c 4 diff. B more than 3 σ below SM prediction
Confirming deviation seen in 1 fb−1 analysis [LHCb, JHEP 07 (2013) 084]
Most precise measurement of relative and total branching fraction
B(Bs0 → φµ+ µ− )
−4
= (7.41+0.42
,
−0.40 ± 0.20 ± 0.21) × 10
B(Bs0 → J/ψ φ)
−7
B(Bs0 → φµ+ µ− ) = (7.97+0.45
,
−0.43 ± 0.22 ± 0.23 ± 0.60) × 10
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
19/36
Global fits to b → s data
W. Altmannshofer et al.,
EPJC 75 (2015) 382
S. Descotes-Genon et al.,
arXiv:1510.04239
Using input from Bs0 → µ+ µ− , B 0 → K ∗0 µ+ µ− , Bs0 → φµ+ µ− ; angular and
differential B measurements
Tension can be reduced with ∆Re(C9 ) ∼ −1, significances around 4 σ
Consistency between angular observables and branching fractions
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
20/36
NP or hadronic effect?
New physics
b
s
Z′
cc̄ loop
γ
µ+
µ−
c
µ−
b
φ
c̄
`−
`+
b
s
d̄
d̄
µ+
s
Possible explanations for shift in C9
et al.] [Buras et al.]
NP e.g. Z 0 [Gauld
[Altmannshofer et al.] [Crivellin et al.]
hadronic charm loop contributions
Anton Poluektov
B physics and BSM models
Leptoquarks
[Hiller et al.] [Biswas et al.]
[Buras et al.] [Gripaios et al.]
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
21/36
NP or hadronic effect?
W. Altmannshofer et al.,
S. Descotes-Genon et al.,
arXiv:1503.06199
arXiv:1510.04239
Possible explanations for shift in C9
et al.] [Buras et al.]
NP e.g. Z 0 [Gauld
[Altmannshofer et al.] [Crivellin et al.]
hadronic charm loop contributions
Leptoquarks
[Hiller et al.] [Biswas et al.]
[Buras et al.] [Gripaios et al.]
q 2 dependence: cc̄ loops rise towards J/ψ, NP q 2 -independent
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
21/36
Photon polarisation measurement in b → sγ
b → sγ is dominated by radiative penguin in the SM. High-ET photon in the final
state.
In the SM, the photon is left-handed (|cL |2 |cR |2 )
λγ =
|cR |2 − |cL |2
|cR |2 + |cL |2
λγ = −1 for b and +1 for b̄.
Significant right-handed component would indicate New Physics (C70 ).
Decays like B → K ∗ (K π)γ are insensitive to γ
polarisation.
Need a four-body decay: B + → K + π + π − γ
Up-down asymmetry:
R1
R0
dΓ
dΓ
d cos θ d cos
− −1 d cos θ d cos
θ
θ
0
±
AUD = ±
R1
dΓ
d
cos
θ
d cos θ
−1
is proportional to λγ
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
22/36
Photon polarisation measurement in b → sγ
LHCb
0.8
0.6
0.4
LHCb
250
1
0.4
0.2
-0.5
0
0.5
[1.3,1.4] GeV/c2
0
-1
1
-0.5
0
0.5
100
50
0
1200
1400
1600
1800
M(Kππ) [MeV/ c2]
1
LHCb
0.8
0.6
0.2
0.2
[1.4,1.6] GeV/c2
-0.5
0
0.5
LHCb
-0.1
0.6
0.4
0
-0.05
1
0.8
0.4
0
-1
LHCb
0.05
1
cosθ
1/N × dN/dcosθ
cosθ
150
0.1
0.2
[1.1,1.3] GeV/c2
0
-1
200
LHCb
0.8
0.6
Aud
300
1/N × dN/dcosθ
1/N × dN/dcosθ
350
1/N × dN/dcosθ
Candidates / ( 8 MeV/c2 )
[PRL 112, 161801 (2014)]
1
1200
1400
1600
1800
M(Kππ) [MeV/ c2]
[1.6,1.9] GeV/c2
1
cosθ
0
-1
-0.5
0
0.5
1
cosθ
Signal yield NK ππγ = 13 876 ± 153
Perform angular fit of cos θ distribution to determine Aud in 4 bins of M(Mππ)
First observation of non-zero photon polarisation at 5.2 σ in combination
To determine precise value for λγ , resonance structure of final state needs to be
resolved
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
23/36
Radiative B decays (B(s) → γγ)
Radiative penguin decays
SM expectations:
B(B 0 → γγ) = (1.5 − 10) × 10−8
B(Bs0 → γγ) = (0.5 − 1) × 10−6
Some SUSY models can enhance it by an order of maginutude (2HDM, RPV).
[PRD 58 (1998) 095014], [PRD 70 (2004) 035008],
[BaBar, PRD 83:032006 (2011)]
25
Bs0 → γγ
[Belle, PRL 100:121801 (2008)]
Events / ( 0.11 GeV )
Events / ( 0.04 GeV )
B 0 → γγ
(b)
20
15
10
10
8
6
4
2
0
5
-2
0
-0.5
-0.4
-0.3
-0.2
-0.1
-0
0.1
0.2
0.3
0.4
0.5
∆ E (GeV)
B(B 0 → γγ) < 3.3 × 10−7
-0.6
-0.4
-0.2
0
0.2
0.4
∆E (GeV)
B(Bs0 → γγ) < 8.7 × 10−6
Belle II expected precision for Bs0 → γγ: 0.3 × 10−6 (so, SM rate could be visible).
Seems hard for LHCb, but not hopeless? Two hard photons, no missing particles...
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
24/36
Unitarity Triangle measurements
Cabibbo-Kobayashi-Maskawa matrix

VCKM
Vud

=  Vcd
Vtd
 
Vub
 
Vcb  ' 

Vtb
Vus
Vcs
Vts
1 − λ2 /2
1 − λ2 /2
−λ
Aλ3 (1 − ρ − iη)

Aλ3 (ρ − iη)
λ



Aλ2
−Aλ2
1
Sensitivity to NP comes from the global consistency of various measurements
ud
excl
excluded area has CL > 0.95
0.6
ed
at C
γ
0.5
L>
∆md & ∆ms
0.4
η
0.95
1.0
sin 2β
CKM
γ
fitter
EPS 15
Tree-only
0.3
α
0.5
0.2
∆md
Vub
0.1
α
β
γ
0.0
α
V ub
V ub
-0.5
Λb
V ub
0.0
0.2
0.4
0.6
0.8
1.0
SL
α
τν
0.7
0.5
εK
γ
0.4
η
CKM
sol. w/ cos 2β < 0
(excl. at CL > 0.95)
fitter
EPS 15
-1.5
-1.0
-0.2
ρ
0.6
-1.0
β
γ
0.0
-0.4
excluded area has CL > 0.95
εK
η
excluded area has CL > 0.95
0.7
1.5
∆md & ∆ms
∆md
sin 2β
CKM
εK
fitter
EPS 15
Loop-only
sol. w/ cos 2β < 0
(excl. at CL > 0.95)
0.3
α
0.2
-0.5
0.0
0.5
1.0
1.5
ρ
2.0
0.1
β
γ
0.0
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
ρ
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
25/36
Unitarity Triangle measurements
Cabibbo-Kobayashi-Maskawa matrix

VCKM
Vud

=  Vcd
Vtd
 
Vub
 
Vcb  ' 

Vtb
Vus
Vcs
Vts
1 − λ2 /2
−λ
Aλ3 (1 − ρ − iη)
λ
1 − λ2 /2
Aλ3 (ρ − iη)
Aλ2
−Aλ2
1




Sensitivity to NP comes from the global consistency of various measurements
ud
excl
1.5
excluded area has CL > 0.95
ed
Some UT measurements potentially affected
by NP:
at C
γ
L>
∆md & ∆ms
0.95
1.0
sin 2β
0.5
η
α
α
V ub
V ub
-0.5
Λb
γ vs. ∆ms
β
γ
0.0
V ub
sin 2β vs. Vub from B → τ ν
SL
α
τν
Vub from SL vs. Vub from B → τ ν
CKM
sol. w/ cos 2β < 0
(excl. at CL > 0.95)
fitter
EPS 15
-0.5
sin 2β from B → J/ψ KS0 vs. sin 2βeff from
e.g. b → sqq̄
εK
γ
-1.0
-1.5
-1.0
γ from trees vs. γ from loops
∆md
εK
0.0
0.5
1.0
1.5
2.0
ρ
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
25/36
SM reference CKM measurement: γ from trees
Measured entirely from tree decays.
All hadronic parameters can be constrained from experiment ⇒ theoretically very
clean (uncertainty < 10−7 [Brod, Zupan, JHEP 1401 (2014) 051])
s
ū
b
B−
ū
Vcb
b
K−
B−
c
ū
D0
u
Vub
c̄
∗
Vcs
ū
Combination of many different modes:
Time-integrated asymmetries in B → DK ,
B → DK ∗ , B → DK π with D → hh, hhhh
Dalitz-plot analysis of D 0 → KS0 h+ h− from
B → DK , B → DK ∗
Time-dependent analysis of Bs → Ds K
Experimentally, just entering precision
measurement regime (< 10%)
D0
s
ū
K−
1-CL
∗
Vus
1
LHCb
Preliminary
0.8
70.9+7.1
−8.5
0.6
0.4
68.3%
0.2
95.5%
0
40
60
80
γ [°]
[LHCb-CONF-2016-001]
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
26/36
Potential NP measurement: γ from loops
Loop diagrams: NP can affect γ
extraction from these modes.
γ [ °]
As in B → DK , interference of several
diagrams, with or without Vub ⇒ CP
violation, phase γ
Extraction of γ from time-dependent
asymmetries of B 0 → π + π − and
Bs0 → K + K − and U-spin symmetry
180
160
(a)
140
120
100
80
60
40
20
0
0
0.2
0.4
0.6
0.8
1
κ
◦
γ = (63.5+7.2
6.7 ) (U-breaking up to 50%)
Large CPV effects seen in other charmless
modes (e.g. B → hhh), but interpretation
in terms of γ needs more work
[LHCb, PLB 741 (2015) 1]
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
27/36
SM reference CKM measurements: |Vub | from semileptonic decays
[LHCb, Nature Phys. 11 (2015) 743]
Use Λ0b sample for |Vub | measurement, cleaner final
state
Measure |Vub |/|Vcb | from
|Vub /Vcb |2 =
B(Λ0b →pµν)
RFF
B(Λ0b →Λ+
c µν)
Fit corrected mass Mcorr =
p
2
pT2 + Mpµ
+ pT
4000
Candidates / (50 MeV/c2)
Candidates / (40 MeV/c2)
|Vub | = [3.27 ± 0.15 ± 0.16(LQCD) ± 0.06(Vcb )] × 10−3
LHCb
Λ c+µ − ν
−
Λ *+
c µ ν
Combinatorial
3000
2000
1000
0
4000
4500
−
5000
5500
Corrected pK π +µ − mass [MeV/c2]
Anton Poluektov
B physics and BSM models
18000
15000
12000
9000
Combinatorial
Mis-identified
D0 p µ − ν
Λ*c+µ − ν
Λ +c µ − ν
N *µ − ν
p µ −ν
LHCb
6000
3000
0
3000
4000
5000
Corrected p µ − mass [MeV/c2]
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
28/36
Potential NP measurement: B → τ ντ
SM transition can be modified at tree level by charged
Higgs or leptoquarks
2
GF mB mτ2
m2
B(B + → τ + ντ )SM =
1 − 2τ
|Vub |2 τB
8π
mB
−4
B(B + → τ + ντ )SM = (0.75+0.10
−0.05 ) × 10
[Belle, PRL 110 131801 (2013)], [PRD 92 051102 (2015)]
[BaBar, PRD 88 031102 (2013)], [PRD 81 051101 (R) (2010)]
Measured with tagged B (SL or hadronic), main signature is absence of extra activity
in EM calorimeter
Anton Poluektov
Events / ( 0.1 GeV/c )
Events / ( 0.05 GeV )
800
700
600
500
400
300
200
100
0
0.0
0.5
B physics and BSM models
1.0
EECL (GeV)
90
80
70
60
50
40
30
20
10
0
0.5
1.0
1.5
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
∗
psig
2.0
(GeV/c)
29/36
Potential NP measurement: B → τ ντ
B(B + → τ ν) = (1.14 ± 0.27) × 10−4 (PDG average)
0.20
×10
p-value
-3
1.0
0.9
0.8
0.15
BR(B → τν)
0.7
0.6
0.5
0.10
0.4
0.3
0.05
0.2
CKM
0.1
fitter
EPS 15
0.00
0.50
0.0
0.55
0.60
0.65
0.70
0.75
0.80
0.85
0.90
sin 2β
[Belle, PRD 92 051102 (2015)]
Belle II is in a good position to measure it with ∼ 5% precision (50 ab−1 ).
[Physics at Super B Factory, arXiv:1002.5012]
LHCb unlikely to contribute, but could probe the similar transitions with muons, e.g.
B → µ+ µ− µ+ νµ (“only” one neutrino in the final state, three tracks making a vertex)
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
30/36
0 mixing
B(s)
b̄
Bs0
t̄
W
s
+N P ?
t
s̄
B 0s
W
0
Evolution of B(s)
system is described by H = M − iΓ/2
Off-diagonal terms M12 , Γ12 responsible for oscillations.
b
Experimental observables:
|∆M| ' 2|M12 | — defines oscillation frequency
|∆Γ| ' 2|Γ12 | cos φ (where φ = arg(−M12 /Γ12 )) — lifetime difference
aSL = Im(Γ12 /M12 ) — flavour-specific asymmetry
Mixing-induced CP asymmetry (interference between B → f and B → B → f )
NP mostly enters M12 as it is determined by box diagram.
∆
SM
M12 = M12
· ∆, where ∆ = |∆| expiφ
[A. Lenz, U. Nierste, PRD 83, 036004 (2011)]
Observables affected by NP (∆ 6= 1):
Oscillation frequency ∆M
Mixing-induced CPV phases 2β (B 0 ), φs (Bs0 )
Semileptonic asymmetries aSL and dimuon asymmetry ASL
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
31/36
Mixing-induced CP violation in B 0 → J/ψ KS0 decays
“Golden mode” at B-factories, but LHCb provides competitive measurement after
recent flavour-tagging improvements.
Time-dependent asymmetry:
A(t) =
S sin(∆mt) + C cos(∆mt)
; S = sin 2β
cosh(∆Γt/2) + A∆Γ sinh(∆Γt/2)
[LHCb, PRL 115, 031601 (2015)]
Signal yield asymmetry
Effective tagging power
εtag (1 − 2ω) = 3.02%
0.4
0.3
0.2
0.1
0
−0.1
−0.2
−0.3
−0.4
sin(2β) ≡ sin(2φ1)
BaBar
0.69 ± 0.03 ± 0.01
PRD 79 (2009) 072009
LHCb
BaBar χc0 KS
0.69 ± 0.52 ± 0.04 ± 0.07
PRD 80 (2009) 112001
BaBar J/ψ (hadronic) KS
1.56 ± 0.42 ± 0.21
Belle
0.67 ± 0.02 ± 0.01
PRD 69 (2004) 052001
PRL 108 (2012) 171802
0.84 +-01..8024 ± 0.16
ALEPH
PLB 492, 259 (2000)
OPAL
3.20
EPJ C5, 379 (1998)
CDF
LHCb
5
10
15
t (ps)
B physics and BSM models
+1.80
- 2.00
± 0.50
0.79
PRD 61, 072005 (2000)
sin 2β = 0.731 ± 0.035 ± 0.020
Anton Poluektov
HF AG
Moriond 2015
PRELIMINARY
+0.41
- 0.44
0.73 ± 0.04 ± 0.02
PRL 115 (2015) 031601
Belle5S
0.57 ± 0.58 ± 0.06
PRL 108 (2012) 171801
Average
0.69 ± 0.02
HFAG
-2
-1
0
1
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
2
3
32/36
Mixing-induced CP violation in Bs → J/ψK + K −
[LHCb, PRD 87 (2013) 112010]
+
K K
−
can be in P wave (φ) or S wave
3 P waves (CP-odd or CP-even), angular analysis to distinguish them
Ambiguity ϕs ↔ π − ϕs is resolved by measuring the P wave strong phase as a
function of mKK .
104
Candidates / 0.067
Candidates / (0.274 ps)
Combined with Bs0 → J/ψπ + π −
Decay time and helicity distributions:
LHCb
103
102
10
LHCb
1200
1000
800
600
400
1
200
10-1
5
Candidates / (0.067 π rad)
1400
LHCb
1200
1000
800
600
400
200
0
-1
-0.5
0
0.5
1
-0.5
0
0.5
cos θµ
LHCb
1200
1000
0.12
0.10
CDF 9.6 fb
1
0.08
800
0.06
400
200
-2
B physics and BSM models
0
2
ϕ [rad]
CMS
20 fb
1
LHCb
3 fb
1
68% CL contours
(
)
Combined
600
0
1
1
1400
cos θK
Anton Poluektov
DØ 8 fb
0.14
0
-1
10
Decay time [ps]
Candidates / 0.067
φs = 0.01 ± 0.07 ± 0.01
Γs = 0.661 ± 0.004 ± 0.006
∆Γs = 0.106 ± 0.011 ± 0.007
1400
ATLAS 19.2 fb
0.4
0.2
1
SM
0.0
0.2
0.4
h
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
33/36
Semileptonic asymmetries
[LHCb, PRL 114 (2015) 041601]
0
Use semileptonic B(s)
decays.
Γ(B → B → f ) − Γ(B → B → f )
Γ(B → B → f ) − Γ(B → B → f )
1−
cos(∆mt)
cosh(∆Γt/2)
-1
-4
-3
µ
= (−4.1 ± 0.6) × 10
= (+1.9 ± 0.3) × 10−5
-3
0µ
-2
[A. Lenz, arXiv:1205.1444]
−4
HFAG Spring '14
D
Standard Model predictions:
d
aSL
s
aSL
0
Ds µνX
LHCb
aSL
2
Standard Model
Ds µνX
Ameas (t) =
1
LHCb D(*)µνX
D0 D(*)µνX
BaBar D*lν
BaBar ll
Belle ll
D0
asls [%]
ACP ≡ aSL =
-2
-1
0
1
asld [%]
No tagging needed. Time-dependent (B 0 ) or time-independent (Bs0 ) SL
asymmetry measurement
3σ tension coming from D0 dimuon asymmetry measurement
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
34/36
0 mixing
B(s)
SM
M12 = M12
· ∆, ∆ = |∆| expiφ
∆
[J. Charles et al., PRD 91, 073007 (2015)]
excluded area has CL > 0.68
excluded area has CL > 0.68
2
2
A SL & aSL (B ) & a (Bs)
d
SL
+
∆ Γ s & τ FS
s & τ s (K K ) & τ s (J/ψ f )
-
0
1
SM point
SM point
∆ md & ∆ ms
0
Im ∆ s
Im ∆ d
1
sin(φ∆ d+2β )
d
∆ md & ∆ ms
φ∆ s-2βs
0
αexp
-1
-1
A SL & aSL (B ) & a (Bs)
d
-2
CKM
fitter
Summer14
-2
-1
NP in Bd mixing - with A
-2
SL
0
Re ∆ d
1
2
CKM
fitter
Summer14
3
-2
-1
SL
NP in Bs mixing - with A
SL
0
1
2
3
Re ∆ s
[J. Charles et al., PRD 89, 033016 (2014)]
If the NP CKM structure is the same as SM, by the end of LHCb upgraded phase and
Belle II, B(s) mixing probes ∆F = 2 NP up to
∼ 20 TeV for tree-level NP
∼ 2 TeV for single-loop NP
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
35/36
Summary
New Physics may manifest itself in B physics in many ways:
Processes involving loops and even trees
Large enhancements of rare processes and small inconsistencies in precision
measurements
∆F = 1 (B decays) and ∆F = 2 (oscillation)
There is a number of small tensions which seem exciting
Enhanced B 0 → µ+ µ−
P50 and a number of other inconsistencies in b → sll
RK , B → Dτ ν (not covered here)
Vub from B → τ ν
“K π puzzle”
But the number of observables is large, so look-elsewhere effect should not be
neglected. Hadronic effects to be taken into account as well.
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
36/36
Backup
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
37/36
A4
0.5
0.5
LHCb
LHCb
0
0
-0.5
0
-0.5
5
10
15
0
5
10
15
q2 [GeV2/ c4]
A 6s
A5
q2 [GeV2/ c4]
0.5
0.5
LHCb
LHCb
0
0
-0.5
0
-0.5
5
10
15
0
5
10
q2 [GeV2/ c4]
Anton Poluektov
[LHCb, JHEP 02 (2016) 104]
A3
B 0 → K ∗0 µ+ µ− CP asymmetries: A3 , A4 , A5 , A6s
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
15
q2 [GeV2/ c4]
38/36
0.5
0.5
LHCb
LHCb
0
0
-0.5
0
-0.5
5
10
15
0
5
10
q2 [GeV2/ c4]
A9
[LHCb, JHEP 02 (2016) 104]
A8
A7
B 0 → K ∗0 µ+ µ− CP asymmetries: A7 , A8 , A9
15
q2 [GeV2/ c4]
0.5
LHCb
0
-0.5
0
5
10
15
q2 [GeV2/ c4]
Anton Poluektov
B physics and BSM models
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
39/36
Bs0 → φµ+ µ− angular analysis
S3
0.5
0.5
0.0
0.0
-0.5
-0.5
S4
LHCb
1.0
1.0
5
10
1.0
15
q2 [GeV2/ c4]
LHCb
-1.0
S7
FL
[JHEP 09 (2015) 179]
1.5
SM pred.
SM (wide)
Data
Data (wide)
5
0.5
0.0
0
-0.5
-0.5
-1
5
15
2
q2 [GeV / c4]
Good agreement of angular obs. with SM predictions
Anton Poluektov
5
10
B physics and BSM models
10
1
0.5
-1.0
LHCb
15
q2 [GeV2/ c4]
LHCb
10
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
15
q2 [GeV2/ c4]
40/36
Bs0 → φµ+ µ− angular analysis
LHCb
A6
A5
[JHEP 09 (2015) 179]
1
1
0.5
0.5
0
0
-0.5
-0.5
5
10
1
-1
15
q2 [GeV2/ c4]
LHCb
A9
A8
-1
5
0.5
0
0
-0.5
-0.5
-1
15
5
2
q2 [GeV / c4]
Good agreement of angular obs. with SM predictions
Anton Poluektov
5
10
B physics and BSM models
10
1
0.5
-1
LHCb
15
q2 [GeV2/ c4]
LHCb
10
11th Franco-Italian meeting on B physics, 11 – 13 April 2016
15
q2 [GeV2/ c4]
41/36