1#
Flavor Physics Today Hassan Jawahery
University of Maryland December 12, 2014
Relevance of Flavor Physics today rests on New Physics reach of FCNC processes & its exclusive access to CPV
2#
Sundrum (CKM 2012) Isidori, Nir, Perez
According to famous theorists:
L = LSM +
ci
ΛNP2 O i + ....∑ No evidence
so far
!potential access to very high energy scales
!Search for deviations from SM
CKM Project Flavor NP project
1980-… today-…
Experimental Landscape:
" BaBar, Belle, Tevatron, BESS and CLEO data, LHCb, CMS, ATLAS (Current and next run)
" Plans for two Super Flavor experiments: " Belle-II at KEKB; peak luminosity 8x1035 cm2 s-1 ! 50 ab-1
" LHCb upgrade; peak luminosity ~1-2x1033 cm2 s-1 ! 50 fb-1
" Dedicated experiments searching for charge lepton violation µ#eγ (at ~10-13) with MEG, µΝ#eN (at 10-16 level) with Mu2e @FNAL and COMET@Jparc.
" Rare Kaon studies at NA62@CERN and Koto@Jparc
3#
4#
The CKM-project has been extremely successful Thanks to the B factories, Tevatron , LHC,
theory insights & LQCD
2001 1995
" The CKM picture of CPV in SM seems to be correct (Nobel 2008) " Flavor remains the only source of observed CP & T-violations " Precisions of rare FCNC processes have significantly improved
Severe constraints on possible scenarios of New Physics But still leaving plenty of room for NP
a
a
_
_
dm6K¡
K¡
sm6 & dm6
ubV
`sin 2
(excl. at CL > 0.95) < 0`sol. w/ cos 2
excluded at CL > 0.95
_
`a
l-1.0 -0.5 0.0 0.5 1.0 1.5 2.0
d
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5excluded area has CL > 0.95
Winter 14
CKMf i t t e r
2014
5#
• Example: NP constraints from Meson Mixing How much NP is allowed?
" Current data: $ Bs is now on equal ground as Bd system (Thanks to LHCb results). $ Data allows NP at 20-30% SM
" Future: If consistency with SM persists- LHCb and Belle-II measurements-
combined with improved LQCD errors- will constrain the magnitude
of NP contribution to ~5% of SM
2003
50 fb-1 LHCb 50 ab-1 Belle-II
2013
Charles, Descotes-Genon, Ligeti, Monteil, Papucci,
Trabelsi (arXiv: 1309.2293).
7 fb-1 LHCb 5 ab-1 Belle-II
hs
hd
hs
hd hd
hd
6#
• Example: NP constraints from Meson Mixing How much NP is allowed?
" Current data: $ Bs is now on equal ground as Bd system (Thanks to LHCb results). $ Data allows NP at 20-30% SM
" Future: If consistency with SM persists- LHCb and Belle-II measurements-
combined with improved LQCD errors- will constrain the magnitude
of NP contribution to ~5% of SM
2003
50 fb-1 LHCb 50 ab-1 Belle-II
2013
Charles, Descotes-Genon, Ligeti, Monteil, Papucci,
Trabelsi (arXiv: 1309.2293).
7 fb-1 LHCb 5 ab-1 Belle-II
hs
hd
hs
hd hd
hd 50 fb-1 LHCb
50 ab-1 Belle-II hd
7#
Stage II: ~2% Vub ~1% Vcb
Stage II: γ at 1o – & α at 1o
A closer look at the numbers reveals some of the challenges ahead
Stage II is counting on ~0.5% accuracy on lattice inputs
8#
%%% large effects %% visible but small effects % unobservable effects
Of course, Flavor-NP program is much broader than mixing: Example of theorist vision: “DNA of flavor physics effects” by W. Altmannshofer, A.J. Buras, S. Gori, P. Paradisi D.M. Straub,
Status of CKM
All is well with the CKM picture at O(10%) level:
9# 9
α = 88.8−4.3+4.5( )o
β = 21.5−0.7+0.8( )o
γ = 70−9.0+7.7( )o
−2βs = +0.00 ± 0.07
α + β + γ = (175.2 ± 9.3)o
93.6−2.9+3.2( )o
25.38−1.57+0.80( )o
66.4−3.3+1.2( )o
−0.0363−0.0012+0.0014
Direct CKM fit
Sin2β tension (driven by B#τν) eased
|Vub| and |Vcb| : Exclusive vs Inclusive results still don’t
agree (~3 σ effects)
sin2β = 0.682 ± 0.019(meas) 0.774−0.036+0.017 ( fit) (< 2.3σ )
a
a
_
_
dm6K¡
K¡
sm6 & dm6
ubV
`sin 2
(excl. at CL > 0.95) < 0`sol. w/ cos 2
excluded at CL > 0.95
_
`a
l-1.0 -0.5 0.0 0.5 1.0 1.5 2.0
d
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5excluded area has CL > 0.95
Winter 14
CKMf i t t e r
Status of CKM
All is well with the CKM picture at O(10%) level:
10# 10
α = 88.8−4.3+4.5( )o
β = 21.5−0.7+0.8( )o
γ = 70−9.0+7.7( )o
−2βs = +0.00 ± 0.07
α + β + γ = (175.2 ± 9.3)o
93.6−2.9+3.2( )o
25.38−1.57+0.80( )o
66.4−3.3+1.2( )o
−0.0363−0.0012+0.0014
Direct CKM fit
Sin2β tension (driven by B#τν) eased
|Vub| and |Vcb| : Exclusive vs Inclusive results still don’t
agree (~3 σ effects)
sin2β = 0.682 ± 0.019(meas) 0.774−0.036+0.017 ( fit) (< 2.3σ )
a
a
_
_
dm6K¡
K¡
sm6 & dm6
ubV
`sin 2
(excl. at CL > 0.95) < 0`sol. w/ cos 2
excluded at CL > 0.95
_
`a
l-1.0 -0.5 0.0 0.5 1.0 1.5 2.0
d
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5excluded area has CL > 0.95
Winter 14
CKMf i t t e r
Current focus
11#
With little theoretical pollution, the road is clear for 1-2 degree precision.
Aim of LHCb-Upgrade and Belle-II
LHCb measurement from B->DK (combined GLW, ADS, GGSZ) is
already as precise as BaBar/Belle
Status of CKM New results on gamma (from tree processes)
γ (combined) = 68.3 ± 7.5o UTFit
γ (combined) = 70.0−9.0+7.7o CKMfitter
B0s system is now an equal player on NP field
φs from a Bs#φφ (penguin decay)
φs=-0.17±0.19 ±0.03 (rad) λ=1.04±0.15±0.03
Consistent with no direct CPV & SM φs
Combined results: φs=0.010±0.0039 (rad) (FALL 2014) Γs=0.6564±0.0031 (ps-1) (SPRING 2014) ΔΓs=0.083 ±0.008 (ps-1)
LHCb upgrade aim: (50 fb-1) σ(φs)~ 0.008 (theory error ~0.003)
Tensions in decays with lepton Semileptonic asymmetry:
Anomalous D0 results persist LHCb consistent with SM
" Lepton Universality Test in radiative decays- 2-3 sigma effect Asl
b (D0)=Cdasld + Csasl
s + C ΔΓ
Γ
" Lepton Universality: B#τ X vs B#µ/e X Sensitive to charged Higgs contribution
Lepton Univsersality test via B#D(*)τν
14#
cb
τ +
H+/W+
ντ
B#D(*)τν
2HDM-II is challenged to fit in both R(D) and R(D*)
3.4σ from SM
bR
tL bL
WsL
γL
Rare and very Rare decays
Bs
Bo
B0s#µ+µ-
Long awaited- finally seen
• SM is triumphant -- Precision measurement is a goal of next run and LHC upgrade along with: (further in future) Bd#µµ/Bs#µµ (key to testing MFV) & Bs#ττ
LHCb & CMS results
50 fb-1
At LHCb upgrade
Serious impact on SUSY parameter space
Most constraining at large tanβ B(Bs,d → µ+µ− )∝ mµ
2 tan6 β
Not all of SUSY is excluded Only the left of green line (for this tanβ)
D. Straub
18#
Evolution of an old friend: b#sγ
Br(b→ sγ ) = (2.32 ± 0.57 ± 0.35) ×10−4 (Exp)
= (3.28 ± 0.33) ×10−4 (SM /Th)
Initial observation at CLEO- 1995
B(B→ Xsγ )NNLL[Eγ > 1.6GeV ) = (3.15 ± 0.23) ×10−4
B(B→ Xsγ )[Eγ > 1.6GeV ) = (3.52 ± 0.23 ± 0.09) ×10−4
2011: Measurements at the B factories
Helicity Flip Suppressed by
~ ms/mb mix
ing
K*(#KsγR)
K*(->KsγL)
First attempt at measuring photon polarization at BaBar & Belle:
via time-dependent CPV in B#K0sπ0 γ
(Gronau, Soni, Atwood)
SK*γ = −0.16 ± 0.22
SM: S <0.04 (probably not the final word) Major item on menu of Belle-II and LHCb-upgrade( Bs#φγ)
Very slow progress
Photon polarization results from LHCb
19#
5.2 σ in favor of Photon polarization– but this measurement doesn’t tell the sign and the magnitude of the polarization.
B#K+π+π-γ Up-Down Asymmetry related to polarization of FS photon
Data mostly Consistent with SM- with a few exceptions
b→sl+l- is providing many tests and some anomalies
Zero crossing point considered highly sensitive to NP effects
Bo→K(*ο)µ+µ- :New Variables less FF dependent
If taken seriously- Global fits to data favor modifying C9, C`9, Introducing a FC Z`
3.7 σ deviation but caution: there is
substantial room in theory predictions
bR
tL bL
WsL
γL
Rare and very Rare decays
Penguin dominated B0 decays measurements of “sin2β”, “φs
”
φs from a Bs#φφ (penguin dominated process)-Analog of B0#φKs
φs=-0.17±0.19 ±0.03 (rad) λ=1.04±0.15±0.03
Consistent with no CPV & SM φs
current results are consistent with SM. But theoretical uncertainties unknown (range of 0.02#0.1 was suggested in the past)
New B0s addition to this program
Non-leptonic charmless B decays Land of penguins & Puzzles
24#
" Direct CPV in B decays originally established by BaBar, Belle, CDF in B0
d#K-π+ :
" Large Direct CP observed in B0s (LHCB & CDF):
Consistent with expected value applying SU(3) to B0
d measurements (Fleischer)
" But the “Kπ puzzle” remains unresolved:
" Large (local) CPV in Dalitz Plane of B#hh’h” Source of these large strong phases?
Acp (Bs0 → K −π + ) = 0.27 ± 0.08 ± 0.02
-1.0 0.0 1.0
CP Asymmetry
ACP =K(b f) K(b f )K(b f)+ K(b f )
ACP (Bu+ → K +π 0 ) − ACP (Bd
0 → K +π− ) = 0.123 ± 0.020
Acp (B0 → K +π− ) = −0.085 ± 0.010
25#
" These effects seen in regions not associated to resonances " Ultimately, will need amplitude analysis " final state re-scattering may have a role; how do we reconcile with 2-body decays (no evidence for large re-scattering)
Large (local) direct CPV in B#hh’h” decays
Mixing & CP Violation in the Charm System " Mixing in D0 system is now firmly established via many observables: " Time evolution of doubly-cabibbo-suppressed D0->K+π- " Lifetime difference in CP-odd and CP-even modes " Dalitz analysis ofD0->Ksπ+π- KsK+K- , K+π-π0, K+π-π+π-, … " Simultaneously fit for CPV:
26#
x = ΔMΓ
= (0.43−0.15+0.14 )%
y = ΔΓ
2Γ= (0.60 ± 0.07)%
D0 mixing is now on firm ground Zero mixing is excluded at >10 σ
No evidence for CPV in the charm system
| qp|= 1.007−0.08
+0.09
ϕ(deg) = −8.7−9.1+8.7
SM : φ <0.6 (deg)
No Evidence for Direct CPV in the charm system
The most sensitive channels: Channel Acp (%) D0#π+π- +0.05 0.15
D0#Κ0sπ0 -0.27 0.21
D0#Κ+Κ- -0.16 0.12
D+#Κ0sπ+ -0.41 0.09
D+#Κ0sΚ+ -0.03 0.17
D+s#Κ0
sΚ+ +0.08 0.26
D+s#Κ0
sπ+ -0.63 0.47
27#
Acp =Γ(D→ f ) − Γ(D→ f )Γ(D→ f ) + Γ(D→ f )
±
±±
±
±
±±
>3σ Expect Acp~ -0.33% induced by indirect CPV in K0
No evidence found for Direct CPV in charm decays
Sensitivities in many channels approaching ~10-3
New results from LHCb
R. Zwicky
Future
28#
Experimental Landscape:
" BaBar, Belle, Tevatron, BESS and CLEO data, LHCb, CMS, ATLAS (Current and next run)
" Plans for two Super Flavor experiments: " Belle-II at KEKB; peak luminosity ~8x1035 cm2 s-1 , 50 ab-1
" LHCb upgrade; peak luminosity ~2x1035 cm2 s-1, 50 fb-1
" Dedicated experiments searching for charge lepton violation m#eg (at ~10-13) with ME, µΝ#eN (at 10-16 level) with Mu2e @FNAL and COMET@Jparc.
" Rare Kaon studies at NA62@CERN and Koto@Jparc
29#
Super Flavor Experiments
• e+e- Super B factory • Small x-section; its mostly about
luminosity (xsection ~1 nb) Asymmetric energy e+ + e- colliders to operate in the Υ(4S) region as well as in the charm threshold region. • SuperB, Italy (originated the
concept – but failed to be funded)
• Super KEKB in Japan- well underway
• At L ~8x1035 /cm2/s
Aiming for a data settof ~ 50 /ab – ~1011 B decays
– ~1011 tau decays – ~1011 charm decays
At LHC: Endowed with large production xsection: its mostly about trigger & pile-up
σcc~6 mb (7 TeV) στ~80 µb (7 TeV) σbb~280 µb(7 TeV) (~500 at 13 TeV)
LHCb at L~2-4x1032/cm2/s Expect ~8/fb by 2018 Bd, Bu, Bs, Bc, Λb,… LHCb upgrade aimed for 2018 To operate at L~2x1033/cm2/s expect ~5/fb/year (total of ~50/fb)
• CMS and ATLAS major players in some key area
30#
The LHCb upgrade The upgrade is designed to run at luminosity
of (1-2)x1033 cm-2s-1 ; Aiming for 50 fb-1
• Requires new approach to the LHCb trigger scheme to overcome L0 (1MHz) limitation.
31
! New Trigger Apporach: " Remove L0 (hardware) trigger
" Readout the detector at the 40 MHz LHC clock rate " Move to a fully flexible software trigger
=>>Major upgrade of LHCb detector required : to cope with increased occupancy, data rate
and radiation dose, & to preserve efficiency and low ghost rate: Replace all readout electronics, entire tracking system (Vertex locator, upstream & downstream tracking detectors) & upgrade
Particle ID system
32#
Belle-II at SuperKEKB
Accelerator Upgrade " low emittance electron injector
" New positron damping ring " New vacuum chambers
" New HER and LER lattice and long dipoles for low emittance
" New IR for low β* " Modified and additional RF for
higher currents
Asymmetric Energy e+e- collider at goal peak Luminosity 8x1035 /cm2/s aiming for 50 ab-1
Design based on Nano-beam scheme proposed by P. Raimondi (Frascati), tight
focusing, larger crossing angle & higher Ib
33#
& Flavor Physics is in excellent health " Precision era is already here; findings are mostly
consistent with SM, but areas of tensions are growing.
" Future looks great: Flavor physics remains one of the key drivers of the search for New Physics beyond SM. " The planned strong experimental program together with advances
on theory front will seriously challenge the SM.