b sll 2015 and New Physics

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1 b sll 15 and New Physics much ado about... something? Sébastien Descotes-Genon Laboratoire de Physique Théorique CNRS & Université Paris-Sud, 9145 Orsay, France in collaboration with L.Hofer, J. Matias, J. Virto WIN 15 (Heidelberg) - June 1th 15 LPT Orsay S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 1

2 Radiative decays b sγ and b sl + l Flavour-Changing Neutral Currents enhanced sensitivity to New Physics effects analysed in model-independent approach effective Hamiltonian 1 b sγ( ) : H F SM =1 VtsV tb C i Q i +... i=1 Q 7 = e g m b sσ µν (1 + γ 5 )F µν b [real or soft photon] Q 9 = e g sγ µ (1 γ 5 )b lγ µ l [b sµµ via Z /hard γ] Q 1 = e g sγ µ (1 γ 5 )b lγ µ γ 5 l [b sµµ via Z ] NP changes short-distance C i and/or add new operators Q i Chirally flipped (W W R ) Q 7 Q 7 sσ µν (1 γ 5 )F µν b (Pseudo)scalar (W H + ) Q 9, Q 1 Q S s(1 + γ 5 )b ll, Q P Tensor operators (γ T ) Q 9 Q T sσ µν (1 γ 5 )b lσ µν l Aim: disentangle hadronic effects from electroweak and NP effects S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15

3 Wilson Coefficients and processes Matching SM at high-energy scale µ = m t and evolving down at µ ref = 4.8 GeV C SM 7 =.9, C SM 9 = 4.1, C SM 1 = 4.3, (formulae known up to NNLO + e.m. corrections) b sγ versus b sll : C 7,7 versus other Wilson coefficients Inclusive versus exclusive: OPE versus form factor uncertainties B X s γ: strong constraints on C 7, C 7 [Misiak, Gambino, Steinhauser... ] B X s ll: only loose constraints [Misiak, Bobeth, Gorbahn, Haisch, Huber, Lunghi... ] B s µµ: recent th. and exp. progress [Misiak, Bobeth, Gorbahn... ] B K ( )ll: New LHCb analysis in Moriond 15 for B K S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 3

4 B K ( )µµ: amplitudes with H eff q, l [C 9( ),1( ),S( ),P( )] A 9 = C 9 M λ sγ µ P L b B L µ C 9 F λ (q ) Electromag [C 7( )] A 7 = C 7 M λ sσ µν P L b B eqµ L ν C q 7 T λ (q ) 4-quark ops [C 1,... )]: nonlocal contribution, related to c c loops A = C d 4 xe iqx M λ T [( sγ µ P L c cγ µ P L b)() Jν em,c c (x)] B e L ν q [L µ lepton current] Two main tasks for the theorists Determine the form factors F λ, T λ using nonperturbative methods Assess the contribution from 4-quark operators, i.e., c c loops in A S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 4

5 B K µµ: angular analysis µ l µ + B K K + θ l : angle of emission between K and µ in di-lepton rest frame θ K : angle of emission between K and K in di-meson rest frame. φ: angle between the two planes q : dilepton invariant mass square d 4 Γ dq d cos θ l d cos θ K dφ = f i (θ K, φ, θ l ) I i i with 1 angular coeffs I i, interferences between 8 transversity ampl.,,, t polarisation of (real) K and (virtual) V = γ, Z L, R chirality of µ + µ pair Amplitudes A,L/R, A,L/R, A,L/R, A t + scalar A s depend on Wilson coefficients C 7, C 9, C 1, C S, C P (and flipped chiralities) B K form factors A,1,, V, T 1,,3 from K Q i B terms describing c c contribution S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 5

6 Four kinematic regions 7 db(b->k*μμ)/ds x 1 (GeV ) γ pole Large recoil Charmonia Low recoil Very large K -recoil (4m l < q < 1 GeV ): γ almost real (C 7 /q divergence and light resonances) Large K -recoil (q < 9 GeV ): energetic K (E K Λ QCD : form factors via light-cone sum rules LCSR) s (GeV ) Charmonium region (q = m ψ,ψ... between 9 and 14 GeV ) Low K -recoil (q > 14 GeV ): soft K (E K Λ QCD : form factors lattice QCD) EFT approaches at low and large-k recoils : expansion in Λ/m b (separating soft and hard dynamics) α S (for dynamics of hard gluons) S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 6

7 B K form factors A1 q.6.4 A q.6.4 V q q GeV q GeV q GeV [Khodjamirian et al.] In the limits of low and large K recoil, separation of scales Λ and m B in the 7 form factors for Large-recoil limit ( q Λ QCD m B ) [LEET/SCET, QCDF] two soft form factors ξ (q ) and ξ (q ) O(α s ) corr. from hard gluons [computable], O(Λ/m B ) [nonpert] [Charles et al., Beneke and Feldmann] Low-recoil limit (E K Λ QCD m B ) [HQET] three soft form factors f (q ), f (q ), f (q ) O(α s ) corr. from hard gluons [computable] and O(Λ/m B ) [nonpert] [Grinstein and Pirjol, Hiller, Bobeth, Van Dyk... ] S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 7

8 From form factors to amplitudes Large recoil: NLO QCD factorisation [Beneke, Feldmann, Seidel] in A,, (non-factor.) in FFs (factor) V, A i, T i = ξ, + factorisable O(α s, Λ/m b ) A,, = C i ξ, + factorisable O(α s, Λ/m b ) + nonfactorisable O(α s, Λ/m b ) Two approaches to get correlations among form factors Extract soft form factors + factorisable power corrections from fit to full form factors [Matias, Virto, Hofer, Mescia, SDG... ] Replace soft form factors + factorisable power corrections by full form factors with correlations [Buras, Ball, Bharucha, Altmanshoffer, Straub... ] Low recoil: OPE + HQET [Grinstein, Pirjol, Hiller, Bobeth, Van Dyk... ] A,, = C i f,, + O(α s ) corrections + O(Λ/m b ) corrections f,, CL(A 1, A ), A 1, V + O(Λ/m b ) corrections [or use directly lattice results for the form factors] S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 8

9 Form-factor independent observables = Observable where (soft) form factors cancel at LO in EFT Zero of forward-back. asym. A FB (s ) = : C9 eff(s ) + m bm B s C7 eff = Transversity asymmetries P 1 = A () T = I 3 = A A I s A + A, P = Are T [Krüger, Matias; Becirevic, Schneider] = I 6s = Re[AL A L AR AR 8I s A + A ] 6 form-factor indep. observ. at large recoil P 1, P, P 3, P 4, P 5, P 6 + form-factor dependent obs. (Γ, A FB, F L... ) [A FB = 3/P (1 F L )] exhausting information in (partially redundant) angular coeffs I i [Matias, Krüger, Mescia, SDG, Virto, Hiller, Bobeth, Dyck, Buras, Altmanshoffer, Straub... ] S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 9

10 Sensitivity to form factors P i designed to have limited sensitivity to form factors S i CP-averaged version of angular coefficient I i P 1 = S 3 F L = I 1c + Ī1c S 3 = I 3 + Ī3 1 F L Γ + Γ Γ + Γ different sensivity to form factors inputs for given NP scenario (form factors from LCSR: green [Ball, Zwicky] vs gray [Khodjamirian et al.]) P 1 apt to discriminate NP (green/gray) vs SM case (yellow) S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 1

11 Power corrections in A,, (non-factor.) in FFs (factor) Observables with limited sensitivity to soft form factors = important role played by O(Λ/m b ) power corrections! Power corrections to form factors F(q ) = F soft (ξ, (q )) + F αs (q ) + a F + b F (q /m B ) +... Set ξ, identifying them with two form factors Central value a F, b F,...: fit to the full form factor F Error on a F, b F,...: 1% of the full form factor F Remaining power corrections to amplitudes multiply part not associated to form factors Ti had with a complex q -dependent factor (1% magnitude) Ti had ( 1 + r i (q ) ) Ti had since contributions from rescattering may yield arbitrary phases S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 11

12 Charm-loop effects Charmonium resonances Large recoil: q 7-8 GeV to avoid J/ψ tail Low recoil: quark-hadron duality OK at a few percent if wide bin Short-distance non-resonant (hard gluons) LO included C 9 C 9 + Y (q ), dependence on m c higher-order short-distance QCD via QCDF/HQET [Beylich, Buchalla, Feldmann] K C9 c c, B K, M1 4 4 K (b) q GeV Long-dist. non-resonant (soft gluons) At large recoil (partly included already in power corrections) Global C BK ( ) 9 using LCSR : for B K, partial computation yields C BK 9 > [Khodjamirian, Mannel, Pivovarov Wang] Perform the separation C BK 9 = δc BK ( ) 9,pert + δc BK ( ) 9,non pert and compute uncertainty by varying nonperturbative part ±δc BK ( ) 9,non pert S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 1

13 Resulting uncertainties for SM predictions: P 5 vs S 5 P 5 and S 5 computed with [Khodjamirian et al.] form factors (green) [Ball and Zwicky] ffs (red) [Jäger and Camalich] approach (yellow) P 5 : Agreement and same errors for [Khodjamirian et al.] and [Ball and Zwicky] S 5 : Different uncertainties for [Khodjamirian et al.] and [Ball and Zwicky] inputs, due to increased sensitivity of S 5 to form factor inputs Agreement within errors between our results for [Ball and Zwicky] and the updated analysis of [Bharucha, Straub, Zwicky] [Jäger and Camalich] approach Non optimal scheme to determine soft form factors No use of information from form factors to set power corrections = range in the absence of info on form factors (enhancing errors) S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 13

14 P 5 in 13 and 15 P P' LHCb preliminary SM from DHMV q GeV q [GeV /c 4 ] Definition: P 5 = Re(AL AL AR AR A ( A + A ) Improved consistency of the 15 data In SM, C 9 C 1 leading to A R,, AL,,, P 5 saturates at -1 when C 9,1 dominates (i.e. q > 5 GeV ) S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 14 )

15 B K µµ ] c 4 /GeV -7 [1 db/dq F H.6.4. Theory LHCb Binned theory LHCb q [GeV /c 4 ].4. Theory LHCb LHCb Binned theory q [GeV /c 4 ] Simpler kinematics: only one angle and 3 observables: Br, F H, A FB [Hiller, Bobeth, Piranishvili] Only Br brings information (other observables are small, both exp. and th.) 3 form factors, down to 1 soft form factor at large recoil Contribution from soft gluons negligible compared to hadronic uncertainties Discrepancy with SM at low q (Br involves C 9 + C 9 ) S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 15

16 B s µµ ] 11 µµ) [1 Br(B d Sensitive to C 1 C 1, C S C S, C P C P NNLO NLO Br(B µµ) [1 ] s p value LHCb+CMS: Br(B s µµ) = CKM f i t t e r 1..9 ( Summer ) 1 9 Theoretical progress Inclusion of B s mixing in time-integrated rate from LHCb and CMS: Br(B s µµ) 1.1Br t= NLO QCD + LO EW NNLO QCD + NLO EW [Fleischer et al., Bobeth et al.] Br(B s µµ) in very good agreement with SM Correlation in SM (and in MFV) Br(B d µµ) t= /Br(B s µµ) t= = S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 16

17 Global fits: 1D hypotheses χ frequentist analysis to determine C i (µ ref ) = Ci SM + Ci NP B K µµ (P 1,, P 4,5,6,8, F L: 5 large-recoil + 1 low-recoil bins), B + K + µµ, B K µµ, B X s γ, B X s µµ, B s µµ (Br), B K γ (A I and S K γ) [Moriond 15, no correlations] Hypothesis Best fit Pull C9 NP C1 NP.6.4 C C C9 NP = C1 NP C9 NP = C1 NP C 9 = C C9 NP = C C 9 = C P5'.5..5 SM charm C 9 NP 1.1 C NP 9 C NP C9 NP < preferred, but alternatives with C9 NP = C1 NP and CNP 9 = C 9 S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 17

18 Global fits: D hypotheses C 9 NP NP C 9' NP C 1 NP C 1' C 9 NP Hyp. Best-fit pt Pull (C7 NP, C9 NP ) (., -1.1) 4. (C9 NP, C1 NP ) (-1.1,.) 4. (C9 NP, C 9 ) (-1., -.1) 4. (C1 NP, C 1 ) (.5,.6) 3.4 Main effect from C 9 Explanations? Z boson Leptoquarks Composite models Difficult with susy (?) [Almannshoffer, Straub, Haisch, Gauld, Peczak, 1 1 C 9 NP 1 1 NP C 1 Buras, De Fazio, Girrbach, Hiller, Schmaltz, Varzielas, Crivellin... ] S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 18

19 Global fits: to be continued Work in progress to add [SDG, Hofer, Matias, Virto, in preparation] Experimental and theoretical correlations (reduce significance) Complex phases in soft-gluon contributions (reduce significance) Electronic modes and B s φµµ (increase significance) New form factors [Bharucha, Straub, Zwicky] (increase significance) General pattern and preferred hypotheses unchanged! NP Re(C 1 ) Re(C NP 9 ) Similar analysis by [Almannshoffer and Straub] Full form factors with correlations (rather than soft form factors) Different form factors, power corrections, c c contributions Similar preferred hyp: C9 NP (3.7 σ) or C9 NP = C1 NP (3. σ) C9 NP can be q -independent (NP?) S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 19

20 Other interesting results R K = Br(B K µµ) Br(B Kee) = ±.36 [1,6] cannot be mimicked by a hadronic effect OK with C µ,np 9 1, or C µ,np 9 = C µ,np 1.5 [C e,np 9,1 ] [Hiller, Schmalz] db/dq (1 7 GeV ) Lattice: B K ll and B s φll form factors B K µ + µ C σ σ σ C9 NP SM [Horgan et al.] SM preds for BRs higher than exp (blue, pink: SM, dashed: C9 NP = C NP 9 = 1.1) Frequentist analysis with only low recoil B q V ll favours C9 NP < (and C 9 mildly negative) Maybe more: LHCb finds Λ b Λµµ with too low branching ratio at large recoil... S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15

21 Outlook b sll transitions Very interesting playing ground for FCNC studies Many observables, more or less sensitive to hadronic unc. Confirmation of LHCb results for B K µµ, supporting C9 NP < with large significance, and room for NP in other Wilson coeffs And a lot theoretical discussions on accuracy of computations and/or interpretation in terms of NP How to improve? Check the size of hadronic effects by comparing different exclusive modes: B K µµ, B K µµ, B s φµµ, Λ b Λµµ... Improve the measurement of q -dependence of the observables Confirm R K by comparing modes with l = e and l = µ Sharpen the estimate of soft-gluon contribs and power corrections Provide lattice form factors over whole kinematic range with corr. A lot of (interesting) work on the way! S. Descotes-Genon (LPT-Orsay) b sll 15 & NP 1/6/15 1