Flavour Physics Beyond the Standard Model: (Minimal Flavour Violation)

Transcription

1 Flavour Physics Beyond the Standard Model: (Minimal Flavour Violation) Federico Mescia ECM & ICC, Universitat de Barcelona - Outline Introduction: Standard Model and Flavour Physics What we understand so far about New Physics: Flavor Problem and Minimal Flavor Violation (MFV) MFV effective theory: Model Independent Analysis: checks and predictions CP 3 -Origins, August 4 th, Odense

2 Standard Model SM Λ UV ( µ M Z ) = gauge( A, ψ ) + Higgs( H,A, ψi) + + Λ U V eff i i i 2 Λ UV (5) (6) see-saw EWPT,FCNC,CPV 1 a a gauge = F F µν µν + iψ Dψ 4 Natural well established (EP) G g =SU(2) U(1) U(1) Y Q SAC ( 64) - EP ad hoc description in the SM + µ + D µ H D H V( H H) ewsb sector + + flavour sector ij Y Hψ ψr h.c 1. not stable;2.not fully investigated EP - B-Factories, Tevatron,, 2 open routes: inear or Non- inear Higgs realisation? THDM SUSY TechniC ittle H. Extra D. The SM is successfully to describe high energy physical phenomena up to µ M Z, well accommodates both Electro-Weak and Flavour constraints.

3 Standard Model SM Λ UV ( µ M Z ) = gauge( A, ψ ) + Higgs( H,A, ψi) + + Λ U V eff i i i 2 Λ UV (5) (6) see-saw EWPT,FCNC,CPV BUT, as effective theory below Μ Planck, how large is the SM Λ UV cut-off? many hints for Beyond SM physics: SuperKamiokande,, WMAP M Planck TeV gravity Λ UV ~ TeV neutrino oscillations Λ UV ~ TeV (see-saw) relic density Λ WIMP 1 TeV, Λ strong 1 TeV matter/anti-matter asymmetries however not clear clues, because of large model dependence! 1TeV M Z Naturalness of Higgs sector would require Λ UV 1 TeV SM µ

4 Standard Model SM Λ UV ( µ M Z ) = gauge( A, ψ ) + Higgs( H,A, ψi) + + Λ U V eff i i i 2 Λ UV (5) (6) see-saw EWPT,FCNC,CPV BUT, as effective theory below Μ Planck, how large is the SM Λ UV cut-off? many hints for Beyond SM physics: M Planck TeV however not clear clues, because of large model dependence! Two main routes to unravel the naturalness of the Higgs sector 1TeV M Z SM µ Direct searches Atlas and CMS; to discover new particles at 1TeV indirect searches MEG, HCb, NA62; epton, B, & K decays to study flavour symmetries of n.d.f

5 Standard Model SM Λ UV ( µ M Z ) = gauge( A, ψ ) + Higgs( H,A, ψi) + + Λ U V eff i i i 2 Λ UV (5) (6) see-saw EWPT,FCNC,CPV BUT, as effective theory below Μ Planck, how large is the SM Λ UV cut-off? Unitarity of the W-W scattering would require Λ UV 1TeV The SM successfully describes both Electro-Weak and Flavour constraints but some tension is already visible i. EWPT and direct Higgs searches imply Λ UV ~ 3-10 TeV (little hierarchy problem) ii. Present Flavour bounds on (6) imply Λ UV ~ TeV (New Physics Flavour Problem)

6 Flavor Physics 2011: egacy of B factories (BaBar, Belle) + Tevatron (CDF, D0)

7 Flavor Physics 2011: = (, ) + + SM gauge Ai Qi Q YUU R H Q YDD RH Spectacular confirmation of the CKM model as the dominant source of flavor and CP violation All flavor-violating interactions encoded in Yukawa coupling to Higgs boson Suppression of flavor-changing neutral currents (FCNCS) and CP violation in quark sector due to unitarity of CKM matrix, small mixing angles, and GIM mechanism.

8 Flavour Physics and the quark sector in picture I. Remarkable consistency between tree-level processes γ, α, V ub, V cb and loop induced observables (FCNC) sin(2β), m ds, ε K, b->sγ... V V + V V + V V = * * * cd cb ud ub td tb 0 II. Remarkable consistency between CPV and CPC observables

9 Flavour Physics and the quark sector: What about BSM effects? The absence of dominant New Physics signals in FCNCs implies strong constraints on flavour pattern BSM NEW Physics FAVOUR PROBEM

10 Model-independent Analysis: Flavour Problem δ C ( µ M ) ( H ψ ) O log. = SM,A, + Λ eff Z i i i 2 i (6) BSM contributions for example, for F=2 mixing: (6) O 4 = R (6) s d s d µ µ OSM = s γ d sγ d R Bounds for generic flavour couplings δc i =1 s d: Λ TeV ε K b d: Λ TeV Μ d b s: Λ TeV Μ s Atlas - CMS log.

11 Model-independent Analysis: Flavour Problem δ C ( µ M ) ( H ψ ) O = SM,A, + Λ eff Z i i i 2 i (6) BSM contributions for example, for F=2 mixing: (6) O 4 = R (6) s d s d µ µ OSM = sγ d sγ d R Dynamical hypothesis on δc i : δc i α S 2 Λ TeV δc i α W 2 Λ TeV Atlas - CMS does not help

12 Model-independent Analysis: Flavour Problem δ C ( µ M ) ( H ψ ) O = SM,A, + Λ eff Z i i i 2 i (6) δc i = 0? very strong restriction! at low energy, the irreducible amount of flavour violation has been measured + Y =, = D m YU V C M m D K U RGE potentially δc i 0 FV FV M Z " gnp = g CKM log " M? Atlas - CMS MFV: δc i small by symmetry! accommodates both flavour problem and RGE logs

13 The SM Flavour Group Chivukula & Georgi 86, J.. Hall &. Randall 90 3 identical replica of the basic fermions family Quark Flavour Group

14 The SM Flavour Group Chivukula & Georgi 86, J.. Hall &. Randall 90 3 identical replica of the basic fermions family Flavour-degeneracy broken by the Yukawa couplings Quark Flavour Group

15 The SM Flavour Group and Minimal Flavour Violation Chivukula & Georgi 86, J.. Hall &. Randall 90 D Ambrosio, Giudice, Isidori & Strumia 02 3 identical replica of the basic fermions family Flavour-degeneracy broken by the Yukawa couplings Promoting Ys to spurions, the Quark Flavour group is restored by

16 The SM Flavour Group and Minimal Flavour Violation Chivukula & Georgi 86, J.. Hall &. Randall 90 D Ambrosio, Giudice, Isidori & Strumia 02 3 identical replica of the basic fermions family Flavour-degeneracy broken by the Yukawa couplings Promoting Ys to spurions, the Quark Flavour group is restored by

17 D Ambrosio, Giudice, Isidori & Strumia 02 The breaking of the flavour symmetry occurs at very high scale and mediated at low energy only by terms Ys preserving the U(3) 5 SM gauge group. At low-energy => a model-independent EFT

18 Exercise 1: Model-independent agrangian for F=2 FCNC observables in MFV _ ε K : K 0 -K 0 mixing exp. err 0.5% Μ s : B 0 s -B0 s mixing exp. err 0.7% Μ d : B 0 d -B0 d mixing exp. err 1% What about the Flavour Problem, Λ cut =10 4?

19 Model-independent Analysis: F=2 constraints in MFV MFV δ C eff = i 2 i Λ O i (6) EFT: D Ambrosio, Giudice, Isidori & Strumia 02 flavour violation mediated by Yukawa beyond SM too!! O basis invariant under S U(3) Q SU(3) SU( 3) UR DR Due to the large top Y, 1) (6) O SM = Q YYγ Q Q Y Y γ Q + µ + µ U U U U Y HU m / m ~ O(1) H D b t D ( V V ) 2 * γ µ γ µ s t d t d s d s ( V V ) 2 * γ µ γ µ b t d t d b d b ( V V ) 2 * γ µ γ µ s t s t b b s b 1 Higgs doublet, SM basis complete -> CMFV Buras, Gambino, Gorbahn, Jager,. Silvestrini 00 ε K Μ d Μ s Adding Higgs doublets, (tanβ enhancement of down-type YDs) 2) 3) + + µ ( Q γ ) 2 YY D DYU YU Q ( V ) 2 V * 2 γ µ γ µ td tb yb b db d ( V ) 2 V * 2 γ µ γ µ ts tb yb b s b s D R YDYY U UQ Q YY U UYDD ( ) 2 R * V tsv tb yb y s b R s b O (6) s Y Y y 2 ~ O(1) U U + t A few extra in a clear pattern between s->d & b->d, b->s transitions Improved attice calculation needed to discriminate this MFV pattern! s R Μ d Μ s

20 Model-independent Analysis: F=2 constraints in MFV MFV δ C eff = i 2 i Λ O i (6) EFT: D Ambrosio, Giudice, Isidori & Strumia 02 flavour violation mediated by Yukawa beyond SM too!! O basis invariant under S U(3) Q SU(3) SU( 3) UR DR Due to the large top Y, 1) (6) O SM = Q YYγ Q Q Y Y γ Q + µ + µ U U U U Y HU m / m ~ O(1) H D b t D ( V V ) 2 * γ µ γ µ s t d t d s d s ( V V ) 2 * γ µ γ µ b t d t d b d b ( V V ) 2 * γ µ γ µ s t s t b b s b 1 Higgs doublet, SM basis complete -> CMFV Buras, Gambino, Gorbahn, Jager,. Silvestrini 00 ε K Μ d Μ s Adding Higgs doublets, (tanβ enhancement of down-type YDs) 2) 3) Y Y y 2 ~ O(1) U U + t + + µ ( Q γ ) 2 YY D DYU YU Q ( V ) 2 V * 2 γ µ γ µ td tb yb b db d ( V ) 2 V * 2 γ µ γ µ ts tb yb b s b s D R YDYY U UQ Q YY U UYDD ( ) 2 R * V tsv tb yb y s b R s b (6) A few extra O s in a clear pattern between s->d & b->d, b->s transitions Improved attice calculation needed to discriminate this MFV pattern! s R Μ d Μ s

21 Model-independent Analysis: F=2 constraints in MFV Due to the large top Y, 1) (6) O SM = Q YYγ Q Q Y Y γ Q Y Y y 2 ~ O(1) U U + t + µ + µ U U U U Λ 5.5 TeV Λ 0.5 TeV loop-suppr. ε K Μ d Μ s Y HU m / m ~ O(1) H Adding Higgs doublets, (tanβ enhancement of down-type YDs) D b t D 2) + + µ ( Q γ ) 2 YY D DYU YU Q Λ 5.1 TeV Μ d 3) D Y YY Q Q YYY D R D U U U U D R Μ Η 5. tanβ/50 TeV Μ s

22 Exercise 2: Model-independent agrangian for F=1 FCNC observables in MFV b s Br(B d X s γ) Εγ >1.6 GeV Br(B d X s l + l ) Br(B s µ + µ ) A FB (B d K*l + l ) s d Br(K + π + νν) + theoretical less cleaner obs

23 Model-independent Analysis: F=1 FCNC constraints in MFV MFV δ C eff = i 2 i Λ O i (6) F=1 Higgs field: F=1 gauge field: F=1 semileptonic field: after ewsb F=1 scalar density: 2 Higgs doublets ~ many F=1 operators 6 F=1 independent combinations after ewsb: (as much as the available F=1 clean observables)

24 Model-independent Analysis: F=1 FCNC constraints in MFV Br(B d X s γ) Εγ >1.6 GeV th (7%): NNO: Misiak et al 06 b s exp (7%): : Br(B d X s l + l ): 3 bins (out of res.) exp (30%): HFAG th (10-25%): s d Br(B s µ + µ ): Babar+Belle NNO: Bobeth et al. 01, Asatrian et al., 02 th (10%): (3.2 ± 0.2) Exp: 1.5 CMS+Hcb 11 A FB (B d K*l + l ): 2 bins exp (large): Babar+Belle 09 Br(K + π + νν): BN th (10%): 6 F=1 independent combinations after ewsb: (can now be constrained by F=1 observables)

25 NEW

26 Br exp-cdf =5.6 Br SM CC events 2 muons in the central region CF events 1 muon in the central region and the other in the forward

27 Model-independent Analysis: F=1 FCNC constraints in MFV Hurth,Isidori,Kamenik, F.M 09 available range for δc i in MFV =>predictions Mind: CKM couplings factorized out O(1TeV) scale consistent to F=2 constraints

28 Model-independent Analysis: F=1 FCNC constraints in MFV Hurth,Isidori,Kamenik, F.M 09 available range for δci in MFV =>predictions 1) Predictions in MFV: way to test and falsify MFV (0.68 ± 0.10) room for NP contributions

29 Model-independent Analysis: F=1 FCNC constraints in MFV Hurth,Isidori,Kamenik, F.M 09 available range for δci in MFV =>predictions A FB (B d K*l + l ), plays a special role but sill large exp err.

30 Model-independent Analysis: F=1 FCNC constraints in MFV Hurth,Isidori,Kamenik, F.M 09 available range for δci in MFV =>predictions B d X s l + l : interesting information from low and high q 2 bin

31 Model-independent Analysis: F=1 FCNC constraints in MFV available range for δci in MFV =>predictions 2)Predictions in MFV: way to test and falsify MFV Hurth,Isidori,Kamenik, F.M 09

32 Model-independent Analysis: F=1 FCNC constraints in MFV available range for δci in MFV =>predictions 3)Predictions in MFV: way to test and falsify MFV tanβ enhancement at work Hurth,Isidori,Kamenik, F.M 09

33 Model-independent Analysis: Flavour Changing Neutral Current constraints in MFV Bounds can be set on the complete set of MFV contributions at both small and large tanβ extra operators Bounds on NP contributions from F=2 obs very constraining Λ 5 TeV in F=1 processes, -mainly δc 7γ very constraining - not all ambiguities can be resolved Λ 6 TeV Tree level NP d.o.f: Λ 5TeV oop-suppressed NP d.o.f: Λ 0.5 TeV ower limit by KK exchange in Xdim

34 Resume: The MFV allows us for a bottom -> up approach testable and model-independent predictions 1 CP MFV CP SM 2 Β s µµ: Br Exp >Br SM with the flavour constraints embedded in MFV, the residual info directly points to Atlas-C MS searches (masses and FC couplings): Interplay Atlas/Hcb Λ 6TeV,,. tanβ, Μ Α tanβ, Μ Η +

35 Where I cheated! A more refined look indeed hints at some tensions with the SM which if confirmed could falsify MFV pattern: CPV in B s -meson mixing β s : ε K from inclusive and exclusive decays V ub from inclusive and exclusive b->u decays But interesting other tension like (g-2) µ, B s µµ,, can be accommodate into MFV exploiting (Yd) helicity-suppressed operators.

36 CPV signals in the B s sector β s : EPS-2011 N( B ψϕ) ( ψϕ ) sin2β s N Bs s NB ( ψϕ) + NB ( s ψϕ ) s t-dependent CP asymmetries HCb golden mode 2β s (rad) β s MFV β s SM 0 Key observable to kill MFV ~<2σ deviation!

37 tensions on F=2 observables upper limit for Λ new?! ε K ε K B K *C SM + = 0.92(2)*B K *C SM 1. RBC 07-08; Aubin et al 09 5% 2. Buras & Guadagnoli 08, 09 unghi & Soni 09 (Gaussian analysis!!) Key observable to kill MFV ~<3σ deviation!

38 V ub tension Key observable to kill MFV ~<2σ deviation!

39 an appealing scenario is MFV at large tanβ = <H u >/< H d > sizable effects on elicity suppressed decays, not yet well measured, and natural explanation of the ~3.5σ in a µ =(g-2) µ /2

40 an appealing scenario is MFV at large tanβ = <H u >/< H d > Isidori,F.M., Paradisi, Temes 08

41 Conclusions We learned a lot about flavour physics in last years Potentially n.d.f at the TeV scale must have a rather sophisticated flavour structure which we have not clearly understood yet NEW Physics flavour facilities FV zero in the SM Rare K decays: e.w loops highest CKM suppression S=1 coupling like ε /ε very clean like sin2β B rare Decays B d,s µµ

42 Conclusions We learned a lot about flavour physics in last years Potentially n.d.f at the TeV scale must have a rather sophisticated flavour structure which we have not clearly understood yet Direct searches Atlas and CMS; NP Cosmology WMAP, PAMEA indirect searches MEG,HCb, P326;

43 an appealing scenario is MFV at large tanβ = <H u >/< H d > potential discovery modes from Hcb to SuperB CC FCNC B + τν B d,s l + l - Very interesting correlations