(μ−,μ+)conversion in nuclei as a probe of new physics

Abstract

We present a detailed analysis of the muonic analogue of neutrinoless double beta decay $({\ensuremath{\mu}}^{\ensuremath{-}},{\ensuremath{\mu}}^{+})$ conversion. We study several lepton number violating (LNV) mechanisms potentially triggering this process: exchange by light and heavy Majorana neutrinos as well as exchange by supersymmetric particles participating in R-parity violating interactions. The nuclear structure is taken into account within the renormalized quasiparticle random phase approximation method. This is the first realistic treatment of nuclear structure aspects of the $({\ensuremath{\mu}}^{\ensuremath{-}},{\ensuremath{\mu}}^{+})$ conversion. We estimate the rate of this process utilizing the existing experimental constraints on the parameters of the underlying LNV interactions and conclude that the $({\ensuremath{\mu}}^{\ensuremath{-}},{\ensuremath{\mu}}^{+})$ conversion will hardly be detectable in the near future experiments.