Flavor Violations in $B$-Mesons within Non-Minimal SU(5)

Abstract

Recent anomalies in $B$-meson decays, such as deviations in $R_{D^{(*)}}$ and $B\to K\nu{\bar\nu}$, suggest possible lepton flavor universality violation and new exotic interactions. In this work, we explore these anomalies within a non-minimal SU(5) grand unified theory (GUT) framework, which introduces a 45-dimensional Higgs representation predicting exotic scalar particles, including the leptoquark $R_2$ and diquark $S_6$. The $R_2$ leptoquark addresses charged current anomalies in $b\to c\tau\nu$ transitions, the $S_6$ diquark contributes to nonleptonic neutral current processes, such as $B\to K\pi$, while at the loop level, diagrams involving the exchanges of the leptoquark, diquark, and the Standard Model particles contribute to $B\to K\nu{\bar\nu}$, offering solutions to longstanding puzzles.