Lepton flavor violation: Constraints from the exotic μ−-eμ− conversion

Abstract

The exotic neutrinoless µ − − e − nuclear conversion is studied within the conventional extensions of the standard model as well as in the minimal supersymmetric (SUSY) models with and without R-parity conservation. The dependence of the µ − e conversion rates on the nucleon and nuclear structure is consistently taken into account. Using our calculated transition matrix elements and the available experimental data on the branching ratio R µe − for 48 Ti and 208 Pb as well as the expected experimental sensitivity for 27 Al employed as a target in the planned at Brookhaven µ − − e − conversion (MECO) experiment, we extract very severe constraints for the flavor violation parameters. We especially emphasize on the constraints resulting for SUSY R-parity violating parameters.

COMET Phase-I Technical Design Report

“…However, as it is widely called as branching ratio in various literature, we call it as branching ratio or BR through out this paper. 2 To calculate the rate of µ−e conversion, proper treatments from the quark level to the nucleon level, and to the nucleus level have to be made [10]. conversion (for a target N) can be written as…”