An Introduction to Explicit R-Parity Violation

TL;DR

This work surveys not $R_p$ symmetry in the MSSM, detailing theoretical motivations, low-energy indirect bounds, and collider phenomenology. It analyzes the renormalizable Rp-violating superpotential with the operators $LLE$, $LQD$, and $UDD$, the proton-decay constraints via discrete symmetries, and the stringent cosmological bounds from GUT-scale baryogenesis. The paper reports current collider constraints from the Tevatron and HERA, including resonant production and multi-lepton signatures, and discusses the cosmological lifetime implications of a decaying LSP. It advocates a two-fold research program—an universal Rp-violating framework with RG running and a topology-based catalog of collider signatures—to ensure coverage of viable signals in both Rp-conserving and Rp-violating MSSM scenarios. The overall message is that both Rp-conserving and Rp-violating MSSM variants must be experimentally pursued, as their phenomenologies are distinct and equally theoretically motivated.

Abstract

I discuss the theoretical motivations for R-parity violation, review the experimental bounds and outline the main changes in collider phenomenology compared to conserved R-parity. I briefly comment on the effects of R-parity violation on cosmology.

Figures (1)

• Figure 1: (a) Proton decay via ${\bar{U}}_1{\bar{D}}_1{\bar{D}}_2$ and $L_1Q_1{\bar{D}}_2$, (b) Tau decay via two $L_1L_3{\bar{E}} _k$ insertions, (c) Neutralino decay via $L_1Q_1{\bar{D}}_1$.