Hunting for New Physics in B-Meson Decays

Recent results from the Belle II experiment explore the decay [latex]B \to s \nu \bar{\nu}[/latex], reinterpreting evidence for [latex]B^{+} \to K^{+} \nu \bar{\nu}[/latex] through marginalized posterior analysis of Wilson coefficients-specifically, sums of [latex]C_{V_R}, S_R, T_R[/latex]-and examining data from [latex]B \to X_s \nu \bar{\nu}[/latex] decays across three distinct mass regions using optimized BDT outputs to differentiate charged and neutral B decays, as well as contributions from [latex]e^{+}e^{-} \to q\bar{q}[/latex] (where q represents up, down, strange, and charm quarks).

Recent results from the Belle and Belle II experiments are pushing the boundaries of the Standard Model by searching for rare decays that could signal the existence of new particles and interactions.