Lepton flavor violation in supersymmetric B-L extension of the standard model

TL;DR

This paper investigates lepton flavor violation in a supersymmetric B-L extended Standard Model, showing suppressed decay rates due to small neutrino Yukawa couplings and proposing detectable LHC signatures involving right-sneutrinos.

Contribution

It demonstrates that LFV processes are suppressed in this model and identifies potential LHC signals from long-lived right-sneutrinos, highlighting novel phenomenological features.

Findings

LFV decay rates are suppressed due to small Yukawa couplings

Right-sneutrinos can be long-lived and produced at the LHC

Same-sign dilepton signals with cross section ~1 pb are possible

Abstract

Supersymmetric B-L extension of the Standard Model (SM) is one of the best candidate for physics beyond the SM that accounts for TeV scale seesaw mechanism and provides an attractive solution for the Higgs naturalness problem. We analyze the charged lepton flavor violation (LFV) in this class of models. We show that due to the smallness of Dirac neutrino Yukawa coupling, the decay rates of l_i -> l_j gamma and l_i -> 3 l_j, generated by the renormalization group evolution of soft SUSY breaking terms from GUT to seesaw scale, are quite suppressed. Therefore, this model is free from the stringent LFV constraints usually imposed on the supersymmetric seesaw model. We also demonstrate that the right-sneutrino is a long-lived particle and can be pair produced at the LHC through the B-L gauge boson. Then, they decay into same-sign dilepton, with a total cross section of order O(1) pb. This signal is one of the striking signatures of supersymmetric B-L extension of the SM.