Parton-Shower Simulations of R-parity Violating Supersymmetric Models

TL;DR

This work addresses the challenge of simulating R-parity violating (Rp) SUSY processes with correct color coherence. The authors develop a comprehensive Monte Carlo framework in HERWIG, incorporating matrix elements for Rp two-body decays and two-to-two resonant production, and extend parton shower and hadronization to Rp dynamics using angular ordering and a cluster model. A key advance is the treatment of baryon-number violating decays, where color flows become nontrivial and require generalized color structures and non-planar flow handling; they also implement strategies to handle random color connections in these decays. Preliminary results demonstrate that color coherence can significantly alter final-state observables and that exploiting these effects can improve signal discrimination for Rp processes at hadron colliders, highlighting the practical importance for experimental Rp searches.

Abstract

We study the colour connection structure of R-parity violating decays and production cross sections, and construct a Monte Carlo simulation of these processes including colour coherence effects. We then present some results from the implementation of these processes in the HERWIG Monte Carlo event generator. We include the matrix elements for the two-body sfermion and three-body gaugino and gluino decays as well as the two-to-two resonant hard production processes in hadron-hadron collisions.

Figures (25)

• Figure 1: Feynman diagram and colour flow for $\mathrm{e^+e^- \rightarrow q \bar{q} g}$.
• Figure 2: Emission in angular ordered cones.
• Figure 3: UDD decays of the ${\tilde{\chi}}^+$.
• Figure 4: UDD decays of the ${\tilde{\chi}}^0$.
• Figure 5: UDD decays of the $\mathrm{{\tilde{g}}}$.