mixing and lepton flavour violation in SUSY GUTs: Impact of the first measurements of

Abstract

In this work we re-examine the correlation between B 0 d,s −B 0 d,s mixing and Lepton Flavour Violation in the light of recent experimental measurements in the Bs system. We perform a generic SUSY analysis of the allowed down squark mass insertion parameter space. In the SUSY GUT scenario this parameter space is then used to make predictions for LFV branching ratios. We find that the recent measurement for the CP phase φs excludes the lowest rates for τ → µγ and provides a lower bound of ∼ 3 × 10 −9 for tan β = 10. Future experimental improvements in the bound on τ → µγ and the measurement of φs will constitute a strong test of the SUSY GUT scenario.

Supersymmetry beyond minimal flavor violation

“…We do not discuss specific SUSY models in this article, referring instead to other contributions to this volume [157,158] for the status of SUSY model building, but consider only a very minimal GUT setup for illustration. One of the most intriguing aspects of SUSY GUTs, which also demonstrates the power of flavour observables to probe even superhigh scales, is the possibility of relations between hadronic and leptonic flavour violation [159,160,161,162,163,164,165,166,167,168,169,170,171,173,174,175,176,177,178,179,180,181]. The effect we are considering here is the following [12,160,161].…”

“…Recall that the expected precision after 5 years of LHCb is about 1 degree, hence this has the potential to turn into a very significant falsification of the SM. It is not difficult to generate such a signal in the MSSM, as b → s FC parameters are not very strongly constrained [179,180,181]. These papers also relate the effects in B s − Bs mixing to the branching fraction for τ → µγ in the context of SUSY GUTs of the type discussed in Section 4.…”

Sflavor mixing map viewed from a high scale in supersymmetricSU(5)

“…(What is denoted by φ Bs in this work is φ J/ψφ s in the notation of HFAG.) We present both of these cases as they lead to very different impressions of the results-the DØ range includes the SM prediction of φ Bs and hence it still works as a bound on the room for new physics, while the HFAG range lies outside the SM value, thereby indicating the size of extra contribution required to account for the discrepancy [47,48]. In order to compare the power of φ Bs measurements at LHCb with that of LFV, we suppose that the future central value of φ Bs is given by the SM, despite the current hint of new physics at the level around 2 σ.…”

“…4 and 6. We would be left with no solution in many cases if we used the HFAG fit (which would be a very interesting outcome on its own [34,35,47,48]). In order to estimate the power of φ Bs measurement at LHCb, we suppose that its future central value will coincide with the SM prediction.…”

Search for New Physics in Bs-mixing

“…Refs. [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42]. TeVatron is continuing to take data and we will get more precise data from the upcomming experiments at LHC 43 or possibly at a SuperB-factory 44 running also at the Υ(5s)-resonance.…”