Flavor Physics Today. Hassan Jawahery University of Maryland December 12, 2014

Transcription

1 Flavor Physics Today Hassan Jawahery University of Maryland December 12, #

2 According to famous theorists: Relevance of Flavor Physics today rests on New Physics reach of FCNC processes & its exclusive access to CPV CKM Project today- Flavor NP project!search for deviations from SM L = L SM + c i Λ NP 2 O i +... No evidence so far!potential access to very high energy scales 2# Isidori, Nir, Perez Sundrum (CKM 2012)

3 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 8x10 35 cm 2 s -1! 50 ab -1 " LHCb upgrade; peak luminosity ~1-2x10 33 cm 2 s -1! 50 fb -1 " Dedicated experiments searching for charge lepton violation µ#eγ (at ~10-13 ) with MEG, µν#en (at level) with 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 excluded area has CL > 0.95 excluded at CL > 0.95 & m s m d sin K m d V ub -1.0 CKM f i t t e r Winter 14 K sol. w/ cos 2 < 0 (excl. at CL > 0.95) " 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 4#

5 How much NP is allowed? Example: NP constraints from Meson Mixing Charles, Descotes-Genon, Ligeti, Monteil, Papucci, Trabelsi (arxiv: ). " Current data: $ B s is now on equal ground as B d system (Thanks to LHCb results). $ Data allows NP at 20-30% SM h s " Future: If consistency with SM persists- LHCb and Belle-II measurementscombined with improved LQCD errors- will constrain the magnitude of NP contribution to ~5% of SM h s h d 7 fb -1 LHCb 5 ab -1 Belle-II h d 50 fb -1 LHCb 50 ab -1 Belle-II h d h d 5#

6 How much NP is allowed? Example: NP constraints from Meson Mixing Charles, Descotes-Genon, Ligeti, Monteil, Papucci, Trabelsi (arxiv: ). " Current data: $ B s is now on equal ground as B d system (Thanks to LHCb results). $ Data allows NP at 20-30% SM h s " Future: If consistency with SM persists- LHCb and Belle-II measurementscombined with improved LQCD errors- will constrain the magnitude of NP contribution to ~5% of SM h s h d 7 fb -1 LHCb 5 ab -1 Belle-II h d 50 fb -1 LHCb 50 h d ab -1 Belle-II h d h d 6#

7 A closer look at the numbers reveals some of the challenges ahead Stage II: ~2% Vub ~1% Vcb Stage II: γ at 1 o & α at 1 o Stage II is counting on ~0.5% accuracy on lattice inputs 7#

8 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, %%% large effects %% visible but small effects % unobservable effects 8#

9 Status of CKM All is well with the CKM picture at O(10%) level: α + β + γ = (175.2 ± 9.3) o excluded area has CL > 0.95 sin 2 K excluded at CL > 0.95 m d & m s m d Direct CKM fit ( ) o ( ) o ( ) o +4.5 α = β = γ = β s = ± 0.07 ( ) o 2.9 ( ) o 1.57 ( ) o V ub Sin2β tension (driven by B#τν) eased sin 2β = ± 0.019(meas) ( fit) (< 2.3σ ) -1.0 CKM f i t t e r Winter 14 K sol. w/ cos 2 < 0 (excl. at CL > 0.95) Vub and Vcb : Exclusive vs Inclusive results still don t agree (~3 σ effects) 9# 9

10 Status of CKM All is well with the CKM picture at O(10%) level: α + β + γ = (175.2 ± 9.3) o excluded area has CL > 0.95 sin 2 K excluded at CL > 0.95 Current focus m d & m s m d Direct CKM fit +4.5 α = ( 88.8 ) o ( ) o ( ) o +0.8 β = γ = β s = ± 0.07 ( ) o ( ) o 1.57 ( ) o CKM f i t t e r Winter 14 V ub K sol. w/ cos 2 < 0 (excl. at CL > 0.95) Sin2β tension (driven by B#τν) eased sin 2β = ± 0.019(meas) ( fit) (< 2.3σ ) Vub and Vcb : Exclusive vs Inclusive results still don t agree (~3 σ effects) 10# 10

11 Status of CKM New results on gamma (from tree processes) LHCb measurement from B->DK (combined GLW, ADS, GGSZ) is already as precise as BaBar/Belle With little theoretical pollution, the road is clear for 1-2 degree precision. Aim of LHCb-Upgrade and Belle-II γ (combined) = 68.3 ± 7.5 o UTFit +7.7o γ (combined) = CKMfitter 11#

12 B 0 s system is now an equal player on NP field Combined results: φ s =0.010± (rad) (FALL 2014) Γ s =0.6564± (ps -1 ) (SPRING 2014) ΔΓ s =0.083 ±0.008 (ps -1 ) LHCb upgrade aim: (50 fb -1 ) σ(φ s )~ (theory error ~0.003) φ s from a B s #φφ (penguin decay) φ s =-0.17±0.19 ±0.03 (rad) λ=1.04±0.15±0.03 Consistent with no direct CPV & SM φ s

13 Tensions in decays with lepton Semileptonic asymmetry: A b sl (D0)=C d a d sl + C s a s sl + C ΔΓ Anomalous D0 results persist LHCb consistent with SM Γ " Lepton Universality Test in radiative decays- 2-3 sigma effect " Lepton Universality: B#τ X vs B#µ/e X Sensitive to charged Higgs contribution

14 Lepton Univsersality test via B#D (*) τν B#D (*) τν b H + /W + c ν τ τ + 3.4σ from SM 2HDM-II is challenged to fit in both R(D) and R(D*) 14#

15 Rare and very Rare decays b R γ L W s L b L t L

16 B 0 s#µ + µ - Long awaited- finally seen B s B o SM is triumphant -- Precision measurement is a goal of next run and LHC upgrade along with: (further in future) B d #µµ/b s #µµ (key to testing MFV) & B s #ττ

17 Serious impact on SUSY parameter space LHCb & CMS results D. Straub 50 fb -1 At LHCb upgrade Most constraining at large tanβ B(B s,d µ + µ ) m µ 2 tan 6 β Not all of SUSY is excluded Only the left of green line (for this tanβ)

18 Evolution of an old friend: b#sγ Initial observation at CLEO Br(b sγ ) = (2.32 ± 0.57 ± 0.35) 10 4 (Exp) = (3.28 ± 0.33) 10 4 (SM / Th) Very slow progress 2011: Measurements at the B factories B(B X s γ )[E γ > 1.6GeV ) = (3.52 ± 0.23 ± 0.09) 10 4 B(B X s γ ) NNLL [E γ > 1.6GeV ) = (3.15 ± 0.23) 10 4 First attempt at measuring photon polarization at BaBar & Belle: via time-dependent CPV in B#K 0 s π0 γ (Gronau, Soni, Atwood) S K*γ = 0.16 ± 0.22 SM: S <0.04 (probably not the final word) Major item on menu of Belle-II and LHCb-upgrade( B s #φγ) mixing K*(#K s γ R ) Helicity Flip Suppressed by ~ m s /m b K*(->K s γ L ) 18#

19 Photon polarization results from LHCb B#K + π + π - γ Up-Down Asymmetry related to polarization of FS photon 5.2 σ in favor of Photon polarization but this measurement doesn t tell the sign and the magnitude of the polarization. 19#

20 b sl + l - is providing many tests and some anomalies Data mostly Consistent with SM- with a few exceptions Zero crossing point considered highly sensitive to NP effects

21 B o K ( * ο) µ + µ - :New Variables less FF dependent 3.7 σ deviation but caution: there is substantial room in theory predictions If taken seriously- Global fits to data favor modifying C 9, C`9, Introducing a FC Z`

22 Rare and very Rare decays b R γ L W s L b L t L

23 Penguin dominated B 0 decays measurements of sin2β, φ s New B 0 s addition to this program φ s from a B s #φφ (penguin dominated process)-analog of B 0 #φk s φ s =-0.17±0.19 ±0.03 (rad) λ=1.04±0.15±0.03 Consistent with no CPV & SM φ s current results are consistent with SM. But theoretical uncertainties unknown (range of 0.02#0.1 was suggested in the past)

24 Non-leptonic charmless B decays Land of penguins & Puzzles CP Asymmetry " Direct CPV in B decays originally established by BaBar, Belle, CDF in B 0 d #K- π + : A cp (B 0 K + π ) = ± " Large Direct CP observed in B 0 s (LHCB & CDF): A cp (B s 0 K π + ) = 0.27 ± 0.08 ± 0.02 Consistent with expected value applying SU(3) to B 0 d measurements (Fleischer) " But the Kπ puzzle remains unresolved: A CP (B u + K + π 0 ) A CP (B d 0 K + π ) = ± A CP = (b f ) (b f ) (b f )+ (b f ) " Large (local) CPV in Dalitz Plane of B#hh h Source of these large strong phases? 24#

25 Large (local) direct CPV in B#hh h decays " 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) 25#

26 Mixing & CP Violation in the Charm System " Mixing in D 0 system is now firmly established via many observables: " Time evolution of doubly-cabibbo-suppressed D 0 ->K+π- " Lifetime difference in CP-odd and CP-even modes " Dalitz analysis ofd 0 ->K s π + π - K s K + K -, K + π - π 0, K + π - π + π -, " Simultaneously fit for CPV: q p = ϕ(deg) = SM : φ <0.6 (deg) x = ΔM Γ = ( )% D 0 mixing is now on firm ground Zero mixing is excluded at >10 σ No evidence for CPV in the charm system y = ΔΓ 2Γ = (0.60 ± 0.07)% 26#

27 No Evidence for Direct CPV in the charm system Γ(D f ) Γ(D f ) A cp = Γ(D f ) + Γ(D f ) The most sensitive channels: ChannelA cp (%) D 0 #π + π ± 0.15 D 0 #Κ 0 sπ ± 0.21 D 0 #Κ + Κ ± 0.12 D + #Κ 0 s π ± 0.09 D + #Κ 0 s Κ ± 0.17 D + s #Κ0 s Κ ± 0.26 D + s #Κ0 s π ± 0.47 No evidence found for Direct CPV in charm decays Sensitivities in many channels approaching ~10-3 >3σ Expect A cp ~ -0.33% induced by indirect CPV in K 0 New results from LHCb R. Zwicky 27#

28 Future 28#

29 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 ~8x10 35 cm 2 s -1, 50 ab -1 " LHCb upgrade; peak luminosity ~2x10 35 cm 2 s -1, 50 fb -1 " Dedicated experiments searching for charge lepton violation m#eg (at ~10-13 ) with ME, µν#en (at level) with and COMET@Jparc. " Rare Kaon studies at NA62@CERN and Koto@Jparc 29#

30 Super Flavor Experiments At LHC: Endowed with large production xsection: its mostly about trigger & pile-up σ cc ~6 mb (7 TeV) σ τ ~80 µb (7 TeV) σ bb ~280 µb(7 TeV) (~500 at 13 TeV) LHCb at L~2-4x10 32 /cm 2 /s Expect ~8/fb by 2018 B d, B u, B s, B c, Λ b, LHCb upgrade aimed for 2018 To operate at L~2x10 33 /cm 2 /s expect ~5/fb/year (total of ~50/fb) CMS and ATLAS major players in some key area 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 ~8x10 35 /cm 2 /s Aiming for a data settof ~ 50 /ab ~10 11 B decays ~10 11 tau decays ~10 11 charm decays 30#

31 The LHCb upgrade The upgrade is designed to run at luminosity of (1-2)x10 33 cm -2 s -1 ; Aiming for 50 fb -1 Requires new approach to the LHCb trigger scheme to overcome L0 (1MHz) limitation.! 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 31

32 Belle-II at SuperKEKB Asymmetric Energy e+e- collider at goal peak Luminosity 8x10 35 /cm 2 /s aiming for 50 ab -1 Design based on Nano-beam scheme proposed by P. Raimondi (Frascati), tight focusing, larger crossing angle & higher I b 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 32#

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. 33#