Zeroing in on Supersymmetric Radiation Amplitude Zeros

TL;DR

This paper explores the supersymmetric radiation amplitude zero in chargino-neutralino production at the LHC, proposing a method to determine the neutralino's wino content by analyzing lepton spectra, aiding in understanding supersymmetric particle composition.

Contribution

It introduces a novel observable based on lepton p_T spectra to identify the neutralino's wino fraction in supersymmetry models at the LHC.

Findings

The amplitude zero can be observed at the upgraded LHC.

The method effectively determines the neutralino's wino content.

The technique is validated on a 19-dimensional MSSM parameter space sample.

Abstract

Radiation amplitude zeros have long been used to test the Standard Model. Here, we consider the supersymmetric radiation amplitude zero in chargino-neutralino associated production, which can be observed at the luminosity upgraded LHC. Such an amplitude zero only occurs if the neutralino has a large wino fraction and hence this observable can be used to determine the neutralino eigenstate content. We find that this observable can be measured by comparing the p_T spectrum of the softest lepton in the trilepton $\chi_1^\pm \chi_2^0$ decay channel to that of a control process such as $\chi_1^+ \chi_1^-$ or $\chi_2^0 \chi_2^0$. We test this technique on a previously generated model sample of the 19 dimensional parameter space of the phenomenological MSSM, and find that it is effective in determining the wino content of the neutralino.