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Unraveling Physics in Quark Sector Transitions

Exploring hints of new physics in B→s transitions, this presentation delves into flavor physics in the quark sector and the CKM matrix in the Standard Model. It discusses free parameters, CP violation, unitarity triangle, and the search for new physics effects.

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Unraveling Physics in Quark Sector Transitions

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  1. Hints of New Physics in b→s transitions (or) Looking for New Physics in Flavour Physics in quark sector Achille Stocchi LAL Orsay Université Paris Sud/IN2P3-CNRS 24 September 2008 DESY-Zeuthen M. Bona, M. Ciuchini, E. Franco, V. Lubicz, G.Martinelli, F. Parodi, M. Pierini, C. Schiavi, L. Silvestrini, A. Stocchi, V. Sordini, C. Tarantino and V. Vagnoni www.utfit.org

  2. Flavour Physics in the Standard Model (SM) in the quark sector: 10 free parameters ~ half of the Standard Model 6 quarks masses 4 CKM parameters Wolfenstein parametrization : l ,A, r, h h responsible of CP violation in SM In the Standard Model, charged weak interactions among quarks are codified in a 3 X 3 unitarity matrix : the CKM Matrix. The existence of this matrix conveys the fact that the quarks which participate to weak processes are a linear combination of mass eigenstates The fermion sector is poorly constrained by SM + Higgs Mechanism mass hierarchy and CKM parameters

  3. * * * VudVub + VcdVcb + VtdVtb = 0 ρ η (bu)/(bc) 2+2 f+,F(1),… ρ η md (1– )2 +2 fBd BBd 2 md/ ms (1– )2 +2 ξ ρ η K [(1–)+ P] BK η ρ a + b + g = p - b - g The Unitarity Triangle The CKM is unitary Size of order l3 : l3 :l3 1

  4. Bccs : 1 /b K : CPV in K decays bcℓ and buℓ Bd and Bs mixing B// : 2/ BDK : 3/ An example on how to fit the UT parameters and fit new physics

  5. Fit with the Standard Model (SM) function(r,h….) Angles Sides + eK r = 0.120 ± 0.034 h = 0.335 ± 0.020 ρ = 0.175 ± 0.027 η = 0.360 ± 0.023

  6. SM Fit Global Fit Dmd,Dms,Vub,Vcb,ek + cos2b + b + a + g + 2b+g Tremendous success of the CKM picture r = 0.155 ± 0.022 h = 0.342 ± 0.014

  7. Should we stop here ? How to look for NP ? And in case of no observation to establish how much room is left for NP effects…? Long story… Some example in next 4 transparencies..

  8. SM predictions of Dms CDF 2006 LEP/SLD 2002 Dms some specific example of NP tests.. SM expectation Δms = (17.5 ± 2.1) ps-1 LEP/SLD 1999 CDF only : signal at 5s Δ ms = (17.77 ± 0.12) ps-1 Tevatron results Limited by Lattice calculations

  9. 1s 3s 5s 2s 4s 6s g Direct measurement From fit γ = (81 ± 13)o(up to π ambiguity) γ = (64.0 ± 3.0)o Summer 2007 Legenda agreement between the predicted values and the measurements at better than : Winter 2008 B factories results LHCb expected to contribute

  10. sin2b vs Vub sin2b=0.668 ± 0.026 1.5s tension Vub(excl.) =(35.0±4.0)10-4 Vub(incl.) =(39.9±1.5 ±4.0)10-4 From fit sin2b=0.736 ± 0.034 B factories results Vub =(34.8±1.6)10-4

  11. Flavour Physics measure NP physics could be always arround the corner WHAT IS REALLY STRANGE IS THAT WE DID NOT SEE ANYTHING…. coupling With masses of New Particles at few hundred GeV effects on measurable quantities should be important Mass scale Problem known as the FLAVOUR PROBLEM Leff <~ 1TeV + flavour-mixing protected by additional symmetries (as MFV) Couplings can be still large if Leff > 1..10..TeV d only operator of D=6 contribute. So that in fact you have a dependence on 1/ L2 If there is NP at scale L, it will generate new operator of dimension D with coefficients proportional to L4-D

  12. Today we concentrate on a Model Independent fit to DF=2 observable which show a 2.5s evidence of NP in the bs transitions

  13. DF=2 Fit in a NP model independent approach Parametrizing NP physics in DF=2 processes

  14. Using the example of the Supersymmetry To help with a more specific example : Example for B oscillations (FCNC-DB=2) : dbd prupper limit of the relative contribution of NP dbdNP physics coupling LeffNP scale (masses of new particles) Minimal Flavour Violation If couplings ~ 1 all possible intermediate possibilities dbq ~ 1 Leff ~ 10/pr TeV (couplings small as CKM elements) Leff ~ 2/pr TeV dbs ~1 dbq ~ 0.1 Leff ~ 1/pr TeV Leff ~ 0.08/pr TeV Leff ~ 0.2/pr TeV dbs ~0.1 UTfit collaboration JHEP 0803:049,2008arXiv:0707.0636 Oversimplified picture : for a quantitative analysis see for instance

  15. Tree processes 13 family Constraints 23 family 12 familiy Today : fit possible with 10 contraints and 7 free parameters (r, h, Cd,jd ,Cs,js, CeK) 5 new free parameters Cs,js Bs mixing Cd,jd Bd mixing CeK K mixing

  16. Bd CBd = 0.96± 0.23 fBd = -(2.9 ± 1.9)o The sin2b tension produces a 1.5s effect on f(Bd) and the asymmetry in the Ad(NP)/Ad (SM) vs f(NP) plot ANP/ASM vs fNP With present data ANP/ASM=0 @ 1.5s ANP/ASM ~1 only if fNP~0 ANP/ASM ~0-30% @95% prob.

  17. Bd Actual sensitivity for a generic NP phase in the Bd sector r=ANP/ASM~10-15% This is not yet a prove that if NP should be MFV violating Just for showing the link between precision and mass scale r upper limit of the relative contribution of NP dbdNP physics coupling LeffNP scale (masses of new particles) Take a case where Leff ~ (200-250) GeV Leff ~ 80/rGeV MORE PRECISION IS NEEDED

  18. Bs Bs sector : very recent results D0,CDF (2006-2007) CDF, D0, LEP CDF (~2006),D0, LEP D0 (2007) D0,CDF (2007-2008) The realm of Tevatron l2 l4 l4 VtdVcd + VtsVcs + VtbVcb = 0 bs Recall that in Bd sector VudVub + VcdVcb + VtdVtb = 0 l3 l3 l3

  19. Nota bene for the experimental result fs = -2bs fs vs of DGs using BsJ/yf Angular (q,j ,y) analysis as a function of the proper time. Similar to measurement of b in BdJ/y K*. Respect to the Bd case, there is additional sensitivity because of DGs term Dunietz,Fleisher and Nierste Phys.ReV D63:114015,2001 Experimentally q and j are well determined from the m from J/y y is the decay plane between the J/yand the f.

  20. Winter 2007 Before ICHEP 2008 with BsJ/yf Not BsJ/yf SM 3s arXiv:0803.0659v1 [hep-ph] 5 Mar 2008 C(Bs) = 1.11 ± 0.32 C(Bs)=1.07±0.29 f(Bs)=(-19.9±5.6)oU(-68.2±4.9)º f(Bs) = (-69±14)º U (-20±14)º U (20±5)º U (72±8)º

  21. Bd1 <--> 3 Bs2 <--> 3 vs 1 <--> 3 70% 10% ANPd/ASMd~0.1 and ANPs/ASMs~0.7 correspond to ANPd/ANPs~ l2i.e. to an additional l suppression.

  22. After ICHEP 2008-CKM2008 ICHEP 2008. D0 released the likelihood without assumptions on the strong phases C(Bs) = 0.97 ± 0.20 (Bs)=(-70 ± 7)oU(-18 ± 7)o SM 3s2.5s New CDF data not included: new CDF likelihood “not ready yet” SM compatibility decreased in the CDF analysis

  23. Here the results from HFAG. Without additional constraints See Diego Tonello (CDF), Lars Sonnenschein (D0) CKM08 Rome

  24. See next page This result, if confirmed, will imply : - of course  NP physics - NP not Minimal Flavour Violation (large couplings..new particles not necessary below the TeV scale • NP model must explain why effects on Bd (which can still be as • large as 20%) and K systems are smaller 1 <-> 2: strong suppression 1 <-> 3: ≤ O(10%) 2 <-> 3: O(1) this pattern is not unexpected in flavour models and in SUSY-GUTs  Flavour physics central - Bd sector, for DF=2 but also DF=1 bs transitions - K sector - of course Bs sector PRECISION IS NEEDED

  25. W- s b f t s B0d s K0 d d b s transitions are very sensitive to NP contributions (DF=1) DF=1 ~ g ~ ~ s b s b New Physics contribution (2-3 families) S(fK) The disagreement is much reduced CFMS PRECISION IS NEEDED B factories results SuperB expected to contribute Im(d23)LR

  26. - D0 and CDF will update their results. They have not used entire dataset. If the NP phase stay so large they could observe it with the full/final dataset - js is a golden measurement for LHCb Simulation done with 4fb-1. φBs = (0.0 ± 1.3)o CBs = 0.99 ± 0.12 But also with much less data, LHCb can observe the effect if will stay so large New studies show that (end 2009 ?) LHCb with 0.5fb-1  s(fBs) = 0.06 ATLAS with 2.5fb-1  s(fBs) = 0.16 See Gaia Lanfranchi CKM08/Rome

  27. Flavour physics in the quark sector is in his mature age In bd transitions NP effect are “confined” to be at order less ~10-15% ! New data from Tevatron show ~2.5s discrepancy from SM in bs transitions If confirmed would implies NP and not Minimal Flavour Violation Tevatron (with full statistics) and LHCb will clarify the discrepancy Flavour Physics is alive more than ever to look for NP beyond SM SuperB

  28. BACKUP MATERIAL

  29. B → tn Belle BR(Btu)=(1.73±0.34)10-4 B factories results SuperB expected to contribute

  30. The problem of particle physics today is : where is the NP scale L ~ 0.5, 1…1016 TeV The quantum stabilization of the Electroweak Scale suggest that L ~ 1 TeV LHC will search on this range What happens if the NP scale is at 2-3..10 TeV …naturalness is not at loss yet… Flavour Physics explore also this range We want to perform flavour measurements such that : - if NP particles are discovered at LHC we able study the flavour structure of the NP - we can explore NP scale beyond the LHC reach If there is NP at scale L, it will generate new operator of dimension D with coefficients proportional to L4-D You could demonstrate that only operator of D=6 contribute So that in fact you have a dependence on 1/ L2

  31. Kaon sector

  32. Flavour specific final states

  33. Tagging is important to separate the time evolution of mesons produced as Bs or anti-Bs. In this way we obtain direct sensitivity to CP-violating phase. This phase enters with terms proportional to cos(2bs) and sin(2bs). Analyses which do not use flavour tagging are sensitive to |cos(2bs)| and |sin(2bs)|, leading to a four-fold ambiguities in the determination of js. Only two-fold ambiguity TeVatron results LHCb expected to contribute

  34. Before ICHEP2008 1.35 fb-1 2.8 fb-1 D0 tagged measurement Other measurements tBs,DG/G,ASL,ACH CDF tagged measurement No likelihood available from D0 Conservative approach used (for details see appendix) All available measured used with and up-to-date hadronic parameters directly from the Likelihood given by CDF Other measurements are also important Notice that the two measurements are in agreement

  35. Modeling D0 data (I) Used by UTFit D0 data The problem is that the singlet Component of the f is ignored. WE REINTRODUCE THE AMBIGUITY (mirroring the likelihood) Strong phase taken also From BdJ/y K* + SU(3) NO AMBIGUITY

  36. - Stability of the result, who is contributing more ? - Is an evidence….How many sigmas ? Including only CDF Including only D0 Gaussian Including only D0 likelihood profile Without tagged analyses D0 and CDF Depending of the approach used (for treating D0 data) js is away from zero from 3s up to 3.7s.

  37. Modeling D0 data (II) DEFAULT METHOD We have the results with 7x7 correlation matrix. Fit at 7 parameters we extract 2 parameters (DGs and js). • Two others approach used to include non-Gaussian tails: • Scale errors such they agree with the quoted “2s” ranges • -Use the 1D profile likelihood given by D0 (fig 2).

  38. ICHEP 2008. D0 released the likelihood without assumption on the strong phases Move from 1.35fb-1 2.8fb-1

  39. Evolution of this result The two most probable peaks of last summer are now enhanced

  40. Looking at the result with a different parametrization js ~ -70o Solution corresponding to js ~ -20o jsNP = (-51 ± 11)o

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