Are BR(b->s gamma) and (g-2)_muon consistent within the Constrained MSSM?

TL;DR

This paper assesses whether the Constrained MSSM can simultaneously explain the experimental values of BR(b->s gamma) and (g-2) of the muon, finding potential tension with e+e- data but not tau decay data.

Contribution

It introduces two statistical tests to evaluate the consistency of BR(b->s gamma) and (g-2) within the CMSSM, considering different data sources and priors.

Findings

Weak or inconclusive tension with e+e- data for (g-2)

Significant ~2sigma incompatibility with e+e- data for both observables

No significant tension with tau decay data

Abstract

We employ two different statistical tests to examine whether, in the framework of the Constrained MSSM, the experimentally determined values of BR(b->s gamma) and the anomalous magnetic moment of the muon, (g-2), are consistent with each other. Our tests are designed to compare the theoretical predictions of the CMSSM in data space with the actual measurements, once all of the CMSSM free parameters have been integrated out and constrained using all other available data. We investigate the value of (g-2) as obtained by using e+e- data alone (which shows a ~3sigma discrepancy with the SM prediction) and as obtained based on tau decay data (which shows a much milder, 1sigma discrepancy). We find that one of our tests returns either a statistically inconclusive result or shows weak evidence of tension between BR(b->s gamma) and the e+e- data based value of (g-2). On the other hand, our second test, which is more stringent in this application, reveals that the joint observations of BR(b->s gamma) and (g-2) from e+e- data alone are incompatible within the CMSSM at the ~2sigma level. On the other hand, for both tests we find no significant tension between BR(b->s gamma) and the value of (g-2) evaluated using tau decay data. These results are only weakly dependent on the three different priors that we employ in the analysis. We conclude that, if the discrepancy between the Standard Model and the experimental determinations of (g-2) is confirmed at the 3sigma level, this could be interpreted as strong evidence against the CMSSM.