Leptonic decays of D_s and B^+ mesons in supersymmetric standard model with R-parity violating interactions

TL;DR

This paper analyzes leptonic decays of D_s and B^+ mesons within an R-parity violating supersymmetric model, finding that interference effects can cancel supersymmetric contributions, allowing for sizable RPV couplings consistent with experimental bounds.

Contribution

It provides a detailed analysis of interference effects between different RPV diagrams in meson decays, highlighting conditions under which RPV couplings can be large.

Findings

Supersymmetric contributions cancel due to interference effects.

RPV couplings can be sizable within experimental bounds.

Constraints on the relative sign of RPV couplings are discussed.

Abstract

We investigate leptonic decays $D_s \to \tau \nu_\tau$ and $B^+ \to \tau \nu_\tau$ in R-parity violating (RPV) supersymmetric standard model. Taking account of interference between the s-channel slepton exchange and the $t$-channel squark exchange diagrams, we find that the supersymmetric contributions are cancelled between two diagrams so that the RPV couplings could be sizable under the experimental bounds. Constraints on the relative sign between the RPV couplings in $s$- and $t$-channel diagrams are also discussed.