Extracting the CP-violating phases of trilinear R-parity violating couplings from $\mu \to eee$

TL;DR

This paper explores how measuring angular distributions and transverse polarizations in the decay ^- ^- e^+ e^- can reveal CP-violating phases of R-parity violating couplings in the MSSM, providing a method to probe new sources of CP violation.

Contribution

It demonstrates a novel approach to determine CP-violating phases of trilinear R-parity violating couplings through combined analysis of decay distributions and polarization measurements in  decay within MSSM.

Findings

Transverse polarization measurements can extract CP-violating phases.

Angular distributions combined with polarization provide phase information.

Method applicable at tree level in R-parity violating MSSM.

Abstract

It has recently been shown that by measuring the transverse polarizations of the final particles in $\mu^- \to e^- e^+ e^-$, it is possible to extract information on the phases of the effective couplings leading to this decay. We examine this possibility within the context of R-parity violating Minimal Supersymmetric Standard Model (MSSM) in which the $\mu^- \to e^- e^+e^-$ process can take place at a tree level. We demonstrate how a combined analysis of the angular distribution of the emitted positrons and their transverse polarization can determine the CP-violating phases of the trilinear R-parity violating Yukawa couplings.