2012/06/30 by Andrzej J. Buras, Jennifer Girrbach · 2 citations
Physics and Astronomy · #Class (philosophy) #Context (archaeology) #Flavour #Hadron #High-Energy Particle Collisions Research #Observable #Particle physics theoretical and experimental studies #Physics beyond the Standard Model #Quantum Chromodynamics and Particle Interactions #Standard Model (mathematical formulation) #hep-ex #hep-lat #hep-ph
paper · pdf · doi:10.1007/jhep01(2013)007
28 pages, 6 figures; v2: Few references and discussion on CP violation in B_s-> mu^+ mu^- added; v3: Several clarifying comments added, conclusions unchanged, version accepted for publication in JHEP
openalex publication_date 2013/01/01 · arxiv created 2013/01/04 · arxiv updated 2015/06/05 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The stringent correlations between flavour observables in models with CMFV are consistent with the present data except for the correlation Delta Ms,d-epsilonK. Motivated by the recent work of Barbieri et al, we compare the CMFV correlations with the ones present in a special class of models with an approximate global U(2)3 flavour symmetry, constrained by a minimal set of spurions governing the breakdown of this symmetry and the assumption that only SM operators are relevant in flavour physics. This analog of CMFV to be called MU(2)3 allows to avoid the Delta Ms,d-epsilonK tension in question because of reduced flavour symmetry and implied non-MFV contributions to Delta Ms,d. While the patterns of flavour violation in K meson system is the same as in CMFV models, the CP-violation in Bs,d meson systems can deviate from the one in the SM and CMFV models. We point out a stringent triple Spsi KS-Spsi phi-|Vub| correlation in this class of models that could in the future provide a transparent distinction between different MU(2)3 models and in the context of these models determine |Vub| by means of precise measurements of Spsi KS and Spsi phi with only small hadronic uncertainties. For fixed Spsi KS the correlation between B(B+ -> tau+nutau) and Spsi phi follows. We also find that MU(2)3 models could in principle accommodate a negative value of Spsi phi, provided |Vub| is found to be in the ballpark of exclusive determinations and the particular MU(2)3 model provides a 25% enhancement of epsilonK. A supersymmetric U(2)3 model worked out in the Barbieri-School appears to satisfy these requirements. However if B(B+ -> tau+nutau)>1.0 10-4 will be confirmed by future experiments only positive Spsi phi is allowed in this framework. We summarize briefly the pattern of flavour violation in rare K and Bs,d decays in MU(2)3 models.