B-meson observables in the maximallyCP-violating MSSM with minimal flavor violation

Abstract

Additional sources of $CP$ violation in the MSSM may affect $B$-meson mixings and decays, even in scenarios with minimal flavor violation (MFV). We formulate the maximally $CP$-violating and minimally flavor-violating (MCPMFV) variant of the MSSM, which has 19 parameters, including 6 phases that violate $CP$. We then develop a manifestly flavor-covariant effective Lagrangian formalism for calculating Higgs-mediated flavor-changing-neutral-current (FCNC) observables in the MSSM at large $\mathrm{tan}\ensuremath{\beta}$, and analyze within the MCPMFV framework FCNC and other processes involving $B$ mesons. We include a new class of dominant subleading contributions due to nondecoupling effects of the third-generation quarks. We present illustrative numerical results that include effects of the $CP$-odd MCPMFV parameters on Higgs and sparticle masses, the ${B}_{s}$ and ${B}_{d}$ mass differences, and on the decays ${B}_{s}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$, ${B}_{u}\ensuremath{\rightarrow}\ensuremath{\tau}\ensuremath{\nu}$, and $b\ensuremath{\rightarrow}s\ensuremath{\gamma}$. We use these results to derive illustrative constraints on the MCPMFV parameters imposed by D0, CDF, Belle, and BABAR measurements of $B$ mesons, demonstrating how a potentially observable contribution to the $CP$ asymmetry in the $b\ensuremath{\rightarrow}s\ensuremath{\gamma}$ decay may arise in the MSSM with MCPMFV.