Flavor changing neutral current processes and the muon anomalous magnetic moment in the supergravity model

TL;DR

This paper examines how supergravity models influence flavor-changing neutral currents and the muon magnetic moment, highlighting the impact of recent Higgs search results on these processes and their potential deviations from the standard model.

Contribution

It analyzes the effects of Higgs search constraints on flavor-changing processes and the muon g-2 in supergravity models, providing updated bounds and correlations.

Findings

B^0--$ar{B}^0$ mixing can be enhanced up to 12% at $ aneta=3$

Deviation in $ ext{CP}$ violation parameter $ ext{$ ext{ε}_K$}$ can reach 25% with non-universal SUSY breaking

SUSY contributions to muon g-2 can range from -30 to 80 in units of 10^{-10} for $ aneta=10$

Abstract

Flavor changing neutral current processes in B and K decays in the supergravity model are revisited taking into account the recent progress of Higgs boson search experiments at LEP. Possible deviations of B^0--$\bar{B}^0$ mixing, the CP violating K^0--$\bar{K}^0$ mixing parameter $\epsilon_K$ from the standard model predictions are reduced significantly in a small $\tan\beta$ region due to the constraints on the SUSY parameter space imposed by the Higgs boson search. With the present bound on the Higgs boson mass, the magnitude of the B^0--$\bar{B}^0$ mixing amplitude can be enhanced up to 12% for $\tanb=3$ in the minimal supergravity. If we relax the strict universality of SUSY breaking scalar masses at the GUT scale, the deviation can be 25%. We also investigate SUSY contributions to the muon anomalous magnetic moment in the supergravity model and show that there is a correlation with the $b \to s \gamma$ amplitude. The SUSY contribution to $a_\mu = \frac{(g-2)_\mu}{2}$ can be (-30 -- $+80)\times 10^{-10}$ for $\tan\beta=10$ and even larger for larger $\tan\beta$. The improved measurement of the muon anomalous magnetic moment in the on-going experiment at BNL will put a strong constraint on SUSY parameter space, especially for a large $\tan\beta$ region.