  This document describes my talk (based on work by JoAnne Hewett, Sandip
Pakvasa, Alexey Petrov, Gagik Yeghiyan and myself) given at the 2011 Meeting of
the Division of Particles and Fields of the American Physical Society
(8/9/11-8/13/11) hosted by the Physics Department at Brown University. We
perform a study of the Standard Model (SM) fit to the mixing quantity Delta
M_B_s in order to bound contributions of New Physics (NP) to B_s mixing. We
then use this to explore the branching fraction of B_s->mu+mu- in several
models of New Physics.
