Revisiting the Electroweakino Sector of the Baryon Number Violating MSSM at the HL-LHC with Deep Neural Networks

TL;DR

This paper uses deep neural networks to project the HL-LHC's sensitivity to electroweakino production in R-parity violating MSSM scenarios, exploring various decay channels and operators to identify potential discovery reach.

Contribution

It introduces a machine learning approach with multi-layer perceptrons to improve sensitivity projections for electroweakino detection in RPV MSSM at the HL-LHC, considering multiple decay channels and operators.

Findings

HL-LHC can probe winos up to 900 GeV with certain operators.

Neural networks enhance signal-background discrimination.

Projected sensitivities vary with RPV operators and decay channels.

Abstract

We study the projected sensitivity of direct electroweakino production $pp \to \tilde\chi_1^{\pm} \tilde\chi_2^0$ at the HL-LHC in a simplified framework with wino-like, mass degenerate $\tilde\chi_1^{\pm}$ and $\tilde\chi_2^0$, and a bino-like lightest neutralino $\tilde\chi_1^0$, assuming R-parity violating~(RPV) through the baryon number violating $\lambda^{\prime \prime}_{112}u^c d^c d^c$ and $\lambda^{\prime \prime}_{113}u^c d^c b^c$ operators. We consider three channels with the $\lambda^{\prime \prime}_{112}u^c d^c d^c$ RPV operator: $Wh$ mediated $1\,\ell + 2\,b + \rm E{\!\!\!/}_T$, $Wh$ mediated $1\,\ell + (\geq 2\,j) + 2\, \gamma + \rm E{\!\!\!/}_T$, and $WZ$ mediated $3\ell + (\geq 2 j) + \rm E{\!\!\!/}_T$. In each channel, we train benchmark-specific multi-layer perceptrons (MLPs), analogous to signal-region classifiers, on the four-momenta of the final state particles along with a small set of higher-level observables to distinguish the signal from the dominant SM backgrounds. We find that the HL-LHC will be able to probe winos up to $\sim 900~$GeV, $\sim 780~$GeV, and $\sim 880~$GeV in the $Wh$ mediated $1\,\ell + 2\,b + \rm E{\!\!\!/}_T$, $Wh$ mediated $1\,\ell + (\geq 2\,j) + 2\, \gamma + \rm E{\!\!\!/}_T$, and $WZ$ mediated $3\ell + (\geq 2 j) + \rm E{\!\!\!/}_T$ channels, respectively, for $m_{\tilde\chi_1^0} \sim 50~$GeV, in the presence of $\lambda^{\prime \prime}_{112}u^c d^c d^c$ couplings, at $2\sigma$ sensitivity. In case the $\lambda^{\prime \prime}_{113}u^c d^c b^c$ operator is solely switched on, the projected sensitivity for winos reach up to $\sim 700~$GeV for $Wh$ mediated $1\,\ell + (\geq 1\,b)\, + (\geq 1j)\, + 2\, \gamma + \rm E{\!\!\!/}_T$ and $\sim 850~$GeV for the $WZ$ mediated $3\ell + (\geq 1 b) + \rm E{\!\!\!/}_T$ channel.