Simulating spin-3/2 particles at colliders

TL;DR

This paper introduces support for simulating spin-3/2 particles in collider physics software, enabling detailed studies of their production and interactions in various theoretical models.

Contribution

It implements spin-3/2 particle interactions in FeynRules and ALOHA, tested with MadGraph 5 and CalcHEP, covering gravitino, gluino, and top-quark excitations.

Findings

Successful implementation of spin-3/2 interactions in simulation tools

Analysis of gravitino and gluino pair-production processes

Investigation of top-quark excitation and angular distributions

Abstract

Support for interactions of spin-3/2 particles is implemented in the FeynRules and ALOHA packages and tested with the MadGraph 5 and CalcHEP event generators in the context of three phenomenological applications. In the first, we implement a spin-3/2 Majorana gravitino field, as in local supersymmetric models, and study gravitino and gluino pair-production. In the second, a spin-3/2 Dirac top-quark excitation, inspired from compositness models, is implemented. We then investigate both top-quark excitation and top-quark pair-production. In the third, a general effective operator for a spin-3/2 Dirac quark excitation is implemented, followed by a calculation of the angular distribution of the s-channel production mechanism.