2005/05/12 by Christoph Bobeth, M. Bóna, Marcella Bona +8
Mathematics · Physics and Astronomy · #Flavour #Mathematical analysis #Mathematics #Neutrino Physics Research #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Upper and lower bounds #hep-ph
paper · pdf · doi:10.1016/j.nuclphysb.2005.06.035
published as Nucl.Phys.B726:252-274,2005 · 26 pages, 12 figures
arxiv created 2005/05/12 · openalex publication_date 2005/07/26 · arxiv updated 2014/11/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the branching ratios of rare K and B decays in models with minimal flavour violation, using the presently available information from the universal unitarity triangle analysis and from the measurements of Br(B -> Xs gamma), Br(B -> Xs l+l-) and Br(K+ -> pi+ nu nubar). We find the following upper bounds: Br(K+ -> pi+ nu nubar)< 11.9 10-11, Br(KL -> pi0 nu nubar)< 4.6 10-11, Br(KL -> mu mubar)SD< 1.4 10-9, Br(B -> Xs nu nubar)< 5.2 10-5, Br(B -> Xd nu nubar)< 2.2 10-6, Br(Bs -> mu mubar)< 7.4 10-9, Br(Bd -> mu mubar)< 2.2 10-10 at 95 % probability. We analyze in detail various possible scenarios with positive or negative interference of Standard Model and New Physics contributions, and show how an improvement of experimental data corresponding to the projected 2010 B factory integrated luminosities will allow to disentangle and test these different possibilities. Finally, anticipating that subsequently the leading role in constraining this kind of new physics will be taken over by the rare decays K+ -> pi+ nu nubar, KL -> pi0 nu nubar and Bs,d -> mu mubar, that are dominated by the Z0 -penguin function C, we also present plots for several branching ratios as functions of C . We point out an interesting triple correlation between K+ -> pi+ nu nubar, B -> Xs gamma and B -> Xs l+l- present in MFV models.