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Hints for new physics in flavour decays. Tsukuba. March 2009

Hints for new physics in flavour decays. Tsukuba. March 2009. CKM Fits : Standard Model and New Physics Stéphane Monteil, LPC, Université Blaise Pascal - in2p3/cnrs On behalf of the CKMfitter group. http://ckmfitter.in2p3.fr. A. Menzel, ATLAS, Humboldt U. Berlin

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Hints for new physics in flavour decays. Tsukuba. March 2009

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  1. Hints for new physics in flavour decays. Tsukuba. March 2009 CKM Fits : Standard Model and New Physics Stéphane Monteil, LPC, Université Blaise Pascal - in2p3/cnrs On behalf of the CKMfitter group. http://ckmfitter.in2p3.fr A. Menzel, ATLAS, Humboldt U. Berlin S. Monteil, LHCb, LPC Clermont-Ferrand V. Niess , LHCb, LPC Clermont-Ferrand J. Ocariz, BABAR, LPNHE Paris S. T’Jampens, LHCb, LAPP, Annecy-le-Vieux V. Tisserand, BABAR, LAPP, Annecy-le-Vieux K. Trabelsi, Belle, KEK Tsukuba J. Charles, Theory, CPT Marseille O. Deschamps, LHCb, LPC Clermont-Ferrand S. Descotes-Genon, Theory, LPT Orsay R. Itoh, Belle, KEK Tsukuba A. Jantsch, ATLAS, MPI Munich H. Lacker, ATLAS & BABAR, Humboldt U. Berlin  Global Fits - CKMfitter Group

  2. Hints for new physics in flavour decays. Tsukuba. March 2009 Outline Introduction The SM CKM Global Fit (experimental inputs, theoretical inputs, numerical results). Model-Independent analysis of NP in DF=2 transitions Test of a specific NP scenario: 2HDM (Type II). Conclusions Global Fits - CKMfitter Group

  3. 1) CKM Matrix: The Four Parameters Consider the Wolfenstein parametrization as in EPJ C41:1-131,2005: unitary-exact and phase convention independent: • l is measured from |Vud| and |Vus| in superallowed beta decays and semileptonic kaon decays, resp. • Ais further determined from |Vcb|, measured from semileptonic charmed B decays. • The last two parameters are to be determined from angles and sides measurements of the CKM unitarity triangle. Global Fits - CKMfitter Group

  4. 1) CKM Matrix: The Four Parameters These four parameters are measured within a global frequentist analysis of the set of relevant observables on which we think to have a good theoretical control. In one table, the observables and the key ingredients: Global Fits - CKMfitter Group

  5. 2) CKM Matrix: The Standard Model Fit. • 2.1) Theoretical inputs: lattice parameters • As underlined in the previous template, several QCD parameters are needed to perform the CKM fit and their knowldege critically impacts the overall precision. Many determinations of these paramaters from lattice QCD with different assumptions and treatment of the errors exist in the literature. • We are facing the question : what to choose ? more and more insistingly. And decided by default to go for our own average, from the set of unquenched results with 2 or 2+1 dynamical fermions. • Alternatives can be found in the literature (see for instance a recent work by Lubicz and Tarantino. We were used to take CKM06 -Tantalo). The single virtue of our approach is that it is algorithmic and hence reproducible. • Note : The concept of theoretical error is ill-defined. Hence, what to say about their combination ? Global Fits - CKMfitter Group

  6. 2) CKM Matrix: The Standard Model Fit. • 2.1) Theoretical inputs: lattice parameters • Method of averaging: • Consider uniquely the statistical uncertainties in the average. • Rfit is taken for the other sources of errors, by the way added linearly for each measurement (when the splitting of the errors is known). • Assign to the average the smallest of the Rfit uncertainty (in order not penalize the best estimate). • Decay constants and bag factors: • Example of the Ds decay constant: fDs Global Fits - CKMfitter Group

  7. 2) CKM Matrix: The Standard Model Fit. 2.1) Theoretical inputs: lattice parameters Details in http://ckmfitter.in2p3.fr Global Fits - CKMfitter Group

  8. 2) CKM Matrix: The Standard Model Fit. • 2.2) Experimental inputs: Winter09 updates. • sin 2b update (latest HFAG average) • Significant improvement for the a measurement: • BaBar published a new measurement of the branching fraction B(B+r+r0) (along w/ increased longitudinal polarization), which strongly constrains the isospin triangles and hence the alpha extraction. Global Fits - CKMfitter Group

  9. 2) CKM Matrix: The Standard Model Fit. 2.2) Experimental inputs: the a measurement. B rr is now the most powerful contribution to the a measurement (see Karim’s talk for details). Global Fits - CKMfitter Group

  10. 2) CKM Matrix: The Standard Model Fit. 2.2) Experimental inputs: the alpha measurement. It is the first time alpha contributes significantly to the metrology of the CKM parameters. Global Fits - CKMfitter Group

  11. 2) CKM Matrix: The Standard Model Fit. 2.3) The overall picture • overall consistency at 95% CL. • CKMmechanism is at workfor describing quark flavor transitions. • KM phase likely to be dominant in B’s. Global Fits - CKMfitter Group

  12. 2) CKM Matrix: The Standard Model Fit. 2.3) Testing the KM mechanism: CP-Violating observables stress the same feature CP-Conserving observables imply CP violation. Angles (small theoretical uncertainties) No angles (theoretical uncertainties dominate) Global Fits - CKMfitter Group

  13. 2) CKM Matrix: The SM Fit inside 95%CL. Tensions, frémissements, hints ? 2.4.1 |Vub| vs sin2b ? It is actually more a |Vub| vs |Vub| tension. We are living with a significant difference between exclusive and inclusive measurements: a longstanding issue. The sin2b measurement prefers the exclusive value. Global Fits - CKMfitter Group

  14. 2) CKM Matrix: The Standard Model Fit. Tensions, frémissements, hints ? 2.4.2 |eK| vs sin2b? Buras & Guadagnoli recently advocated necessity of an additional parameter in the SM lowering the prediction. The resulting tension |eK| vs sin2b might have very appealing explanations(Soni & Lunghi). • We included the multiplicative additional parameter and got the result in green. • The tension arises if all the uncertainties on QCD parameters are Gaussian. Global Fits - CKMfitter Group

  15. 2) CKM Matrix: The Standard Model Fit. Tensions, frémissements, hints ? 2.4.3 BR(B+t+n)vs sin 2b? Actually a large effect: Tension between sin(2b)(I) & BR(B+t+n) (II) (through |Vub|): RemovingI/II in the CKM global fit, the c2min dropsby 2.3/2.4s. Global Fits - CKMfitter Group

  16. 2) CKM Matrix: The Standard Model Fit. 2.4.3 BR(B+t+n)vs sin 2b? Looking in the detail, it is a non trivial correlation; we could think of |Vub|, |eK| , fBd…Actually, analysing simultaneouly Dmd and BR(B+t+n) gives a theory-free determination of the BBd factor and the tension is brought there. Experimental fluctuation ? LQCD input? NP ? in mixing ? Global Fits - CKMfitter Group

  17. 3) New Physics in DF = 2 transitions. Aim at investigating in a model-independent manner the space left to NP contributions by the current data. Only two additional parameters added. Several equivalent parametrisations exist: • Hypotheses: • only the short distance part of the mixing processes might receive NP contributions. • Unitary 3X3 CKM matrix. • tree-level processes are not affected by NP (so-called SM4FC: bqiqjqk(ijk)). As a consequence, the quantities which do not receive NP contributions in that scenario are: Global Fits - CKMfitter Group

  18. 3) New Physics in DF = 2 transitions. We are using in the following the cartesian coordinates parametrisation, following Nierste & Lenz (JHEP0706:072,2007) The predictions of the observables sensitive to NP contributions are modified as: Global Fits - CKMfitter Group

  19. 3) New Physics in DF = 2 transitions. • The real and imaginary parts are mostly constrained by Dmd (circle), sin2b (arcs) and a. • Additional information is brought by the semileptonic asymmetries ASL and DG (hidden in that plot for the sake of clarity). Global Fits - CKMfitter Group

  20. 3) New Physics in DF = 2 transitions. • No evidence of NP but a departure from the SM at the level of 2 s. • Mostly driven by BR(B+t+n): • Within our hypotheses, we shall conclude that a NP phase can accomodate the large value of BR(B+t+n). • Sizeable NP contributions in Bd system are still allowed. Global Fits - CKMfitter Group

  21. 3) New Physics in DF= 2 transitions. • The Bs system: The SM weak phase in the Bs mixing is very well predicted: Global Fits - CKMfitter Group

  22. 3) New Physics in DF= 2 transitions. • Dominant constraints: • Dmsagrees with SM. • (fs=-2bs,DGs)through time dependent angular analysis of Bs J/yfby D/CDF(HFAG’08 update) is2.2saway from SM. • The departure from SM value is 1.9s. The main message is that the additional information (semileptonic asymmetries and lifetime difference) with the current experimental precision only marginally play. The Fs measurement is almost uniquely defining the discrepancy. A global fitter cannot say much there. Eagerly awaiting the Tevatron update. With the expected LHC luminosity in 2009-2010, LHCb is at the corner. Global Fits - CKMfitter Group

  23. 3) New Physics in DF= 2 transitions. • Intermediate Conclusions • The CKM mechanism faced a great success in describing flavor dynamics of many constraints from vastly different scales. It’s the dominant source of CP violation in B system. The BaBar and Belle experiments provided fantastic measurements in that respect. • Stringent constraints on NP, established in a model-independent manner in DF=2 transitions , are already existing in the Bd system. The Tevatron measurements in the Bs sector start to significantly constraint NP in the Bs sector. • We have not entered the precision era yet. A precise g measurement is missing. • Most prominent deviations from SM : BR(B+t+n)vs sin 2b and Fs value. Global Fits - CKMfitter Group

  24. 4) Test of a Specific Model : 2HDM(II) • Motivation: it is a simple and predictive extension of the Standard Model. Same structure for the quark sector but new flavour changing charged interactions mediated by a charged Higgs. • Track charged Higgs contributions into tree or loop decays. Redifinition of the SM expression through corrections implying only 2 additionnal parameters: • 2HDM is embedded into supersymmetric models (MSSM). • Charged Higgs transition is something we immediately imagine for BR(B+t+n). • Note: There are of course neutral higgses in 2HDM, which do not enter the processes under consideration in this study. Global Fits - CKMfitter Group

  25. 4) Test of a Specific Model : 2HDM(II) • All inputs are potentially subjected to receive charged Higgs contributions. • Yet, we neglected charged Higgs contribution for the following inputs, hence used todetermine the apex of the unitarity triangle. Driven by (m_light/m_heavy)2 couplings  |Vud|, |Vub|, |Vcb| and g(a). • We consider several observables subjected to receive Higgs contributions: • Leptonic decays • Semileptonic decays • The partial width of Z to bb (used to be a hint of NP!) • b sg • Note: we did not consider in the present study the observables related to mixing, neither Bs mm nor b sll. Global Fits - CKMfitter Group

  26. 4) Test of a Specific Model : 2HDM(II) • The deviations w.r.t the SM predictions for the observables of interest. The orange band stands for two standard deviations. The experimental uncertainty is given at one standard deviation. Global Fits - CKMfitter Group

  27. 4) Test of a Specific Model : 2HDM(II) • Leptonic decays: • Where M denotes any meson. [The radiative corrections are only relevant for light hadron decays]. • The branching fraction is modified in the presence of Higgs contribution as : • Two solutions to find back to SM prediction: • rH = 0. Generally send the H mass to infinity. • rH =-2. Fine-tuned solution different for each meson. Global Fits - CKMfitter Group

  28. 4) Test of a Specific Model : 2HDM(II) / leptonic decays individual results Global Fits - CKMfitter Group

  29. 4) Test of a Specific Model : 2HDM(II) / leptonic decays individual results • Most of the indvidual fined-tuned solutions are removed at 95% CL • Large tan b are excluded at small Higgs masses. Global Fits - CKMfitter Group

  30. 4) Test of a Specific Model : 2HDM(II) / semi-leptonic decays individual results • Semileptonic decays help further to remove indvidual fined-tuned solutions at 95% CL. Global Fits - CKMfitter Group

  31. 4) Test of a Specific Model : 2HDM(II) / b sg Obviously a relevant laboratory for New Physics.Vastly investigated in the literature. • A.J. Buras, M.Misiak, M.Munz, S. Pokorski, Nucl Phys. B424 • K. Chetyrkin, M. Misiak, M. Munz, Phys. Lett. B400. • P. Gambino, M.Misiak Nucl., Phys. B611. • M.Misiak, M. Steinhauser Nucl. Phys. B764. • C. Degrassi, P. Gambino, P. Slavich, CERN/2007-265 • T. Besmer, C. Greub, T. Hurth, Nucl. Phys. B 609. • Calculated at NNLO (Misiak et al., 2006) • The normalized branching fraction (in notation from Gambino et al.) reads as: • For practical reasons, we’ve chosen to parametrize the P and N according to • Where A and B are two functions depending on a reduced set of relevant parameters (mb, mt, mc (btw, the most critical input)). • They are fitted to reproduce the results from the open package SusyBSG (degrassi et al.) Global Fits - CKMfitter Group

  32. 4) Test of a Specific Model : 2HDM(II) / the combined constraint • Leptonic decays (mainly BR(B+t+n)) constrain the parameter space at large tanb. • Rb constrains at small tanb. • We are ending with a unidimensionnal constraint on the charged Higgs mass mostly brought by b sg. • 2HDM(II) does not perform better than the SM. Global Fits - CKMfitter Group

  33. 4) Test of a Specific Model : 2HDM(II) / the combined constraint • No constraint on tanb at 95 %CL. Global Fits - CKMfitter Group

  34. 5) Conclusion • overall consistency at 95% CL. • KM mechanism is at work. Global Fits - CKMfitter Group

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