A Search for New Physics through Measurement of the Branching Fraction for B Meson decays to Muon Pairs with the ATLAS Experiment at √s = 13 TeV

The rare B_s⁰ → μ⁺μ^- and B_d⁰ → μ⁺μ^- decays are flavor-changing neutral current processes that are highly suppressed in the Standard Model. The experimental search for these decays is a compelling method to find New Physics indirectly, complementary to efforts of direct detection of particles and interactions yet unknown; thus, it can potentially have significant impact on Beyond the Standard Model theories. I will discuss the analysis strategy, with particular attention to the validation of Machine Learning techniques used to separate the signal from the huge background, and the potential for measuring the branching fractions of the two decays simultaneously using 139 fb^-1 of proton-proton collision data collected between 2015 - 2018 by the ATLAS experiment at the Large Hadron Collider.