Constraints on $Wtb$ anomalous coupling with $ B\to X_{s}\gamma $ and $B_{s}\to\mu^{+}\mu^{-}

TL;DR

This paper investigates how anomalous $Wtb$ couplings affect rare B-meson decays, revealing new constraints and addressing theoretical consistency issues in the effective vertex calculations.

Contribution

It provides a detailed calculation of $b o s$ transition amplitudes with $Wtb$ anomalies, identifies Ward identity violations, and derives new bounds from B-meson decay data.

Findings

Existence of Ward identity violating terms in $b o s o ext{photon}$ vertex.

$Br(B_s o \mu^+b ext{muon pair})$ constrains $\, ext{delta} v_L$.

Stringent bounds on $v_R$ and $g_L$ from $Br(B o X_s o ext{photon})$.

Abstract

We calculate the amplitudes of $b\to s$ transition in extension of the Standard Model with $Wtb$ anomalous couplings. We found that i) there exist the Ward identity violating terms in effective vertix of $b\to s\gamma$. The terms, which come from the tensor parts of $Wtb$ anomalies, and can be canceled exactly by introducing corresponding $Wtb\gamma$ interactions, ii) $Br(B_{s} \to \mu^{+}\mu^{-})$ provides unique information on $\delta v_L$ which is set to zero in top decay experiments, and stringent bounds on $v_R,\ g_L$ by $Br(B\to X_s\gamma)$ are obtained.