Effective squark/chargino/neutralino couplings: MadGraph implementation

TL;DR

This paper implements an effective description of squark interactions with charginos and neutralinos in MadGraph, including Yukawa couplings and supersymmetry-breaking effects, validated through decay width comparisons and cross-section calculations.

Contribution

It introduces a new MadGraph model incorporating effective squark couplings with charginos and neutralinos, accounting for supersymmetry-breaking effects.

Findings

Validated the implementation against FeynArts/FormCalc results.

Provided cross-section calculations for top-squark decays.

Demonstrated the model's accuracy in simulating squark interactions.

Abstract

We have included the effective description of squark interactions with charginos/neutralinos in the MadGraph MSSM model. This effective description includes the effective Yukawa couplings, and another logarithmic term which encodes the supersymmetry-breaking. We have performed an extensive test of our implementation analyzing the results of the partial decay widths of squarks into charginos and neutralinos obtained by using FeynArts/FormCalc programs and the new model file in MadGraph. We present results for the cross-section of top-squark production decaying into charginos and neutralinos.