Hints of large tan β in flavour physics

Motivated by the first evidence of the Bu -> tau upsilon transition reported by Belle [Belle Collaboration, K. Ikado, et al., hep-ex/0604018] and by the precise Delta M-Bs measurement by CDF [CDF Collaboration, G. Gomez-Ceballos, Talk presented at FPCP 2006, Vancouver, Canada, 9-12 April 2006, http://fpcp2006.triumf.ca/; D Collaboration, V Abazov, hep-ex/0603029], we analyse these and other low-energy observables in the framework of the MSSM at large tan beta. We show that for heavy squarks and A terms (M-(q) over bar, A(U) greater than or similar to 1 TeV) such scenario has several interesting virtues. It naturally describes: (i) a suppression of B(Bu -> tau upsilon) of (10-40)%, (ii) a sizable enhancement of (g - 2)(mu), (iii) a heavy SM-like Higgs (m(h0) similar to 120 GeV), (iv) small non-standard effects in Delta M-Bs and B(B -> X-s gamma) (in agreement with present observations). The possibilities to find more convincing evidences of such scenario, with improved data on B(B-u -> tau upsilon), B(B-s,B-d -> l(+)l(-)) and other low-energy observables, are briefly discussed. (c) 2006 Elsevier B.V. All rights reserved.