Three-Body Decays of Sleptons with General Flavor Violation and Left-Right Mixing

TL;DR

This paper calculates three-body slepton decay widths considering general flavor violation and left-right mixing, revealing new decay channels relevant for supersymmetry models with gravitino LSPs and aiding in precision measurements.

Contribution

It provides the first comprehensive analysis of slepton three-body decays with arbitrary flavor violation and mixing, extending previous flavor-conserving studies.

Findings

New decay channels due to flavor violation and mixing

Results applicable to models with gravitino LSPs

Implementation in SPICE for collider simulations

Abstract

We determine the widths of three-body decays of sleptons, $\tilde{l}^- \to \tilde{l}^{\pm} l^- l^{\mp}, \tilde{l}^- \nu \bar{\nu}, \tilde{l}^- q \bar{q}$, in the presence of arbitrary slepton flavor violation and left-right mixing. These decays are important in scenarios in which the lightest supersymmetric particle is the gravitino, a generic possibility in models with gauge- and gravity-mediated supersymmetry breaking. Three-body decays have been discussed previously assuming flavor conservation and left-right mixing in only the stau sector. Flavor violation and general left-right mixing open up many new decay channels, which provide new avenues for precision mass measurements and may play an essential role in solving the standard model flavor problem. We present results for toy models with two-generation mixing, and discuss the implementation of these results in SPICE, a program that simplifies collider event simulations of flavor-violating supersymmetric models.