Search for charginos and neutralinos with $B-L$ $R$-parity violating decays in $\sqrt{s}=13$ TeV and $13.6$ TeV $pp$ collisions with the ATLAS detector

TL;DR

This paper reports a search for charginos and neutralinos decaying via $B-L$ $R$-parity violation in proton-proton collisions at 13 and 13.6 TeV, setting new limits on their masses and decay modes using ATLAS data.

Contribution

It introduces a novel search targeting Higgs decay channels of charginos and neutralinos with $B-L$ $R$-parity violation, extending previous limits in this model.

Findings

No significant excess observed over Standard Model predictions.

Excluded charginos and neutralinos with masses between 150 GeV and 1100 GeV at 95% CL.

Set model-independent cross section limits for beyond Standard Model processes.

Abstract

A search is performed for the electroweak pair production of charginos and associated production of a chargino and neutralino, each of which decays through an $R$-parity-violating coupling into a lepton and a $W$, $Z$, or Higgs boson. This search targets the Higgs boson decay channel of the charginos and neutralinos, using events with three or more $b$-tagged jets and one or two electrons or muons. The analyzed data corresponds to an integrated luminosity of 140 fb$^{-1}$ and 56 fb$^{-1}$ of proton-proton collision data produced by the Large Hadron Collider at center-of-mass energies of $\sqrt{s}=13$ TeV and $\sqrt{s}=13.6$ TeV respectively, collected by the ATLAS experiment between 2015 and 2023. The data are found to be consistent with predictions from the Standard Model. The results are interpreted as limits at 95% confidence level on model-independent cross sections for processes beyond the Standard Model. Limits are also set on the production of charginos and neutralinos for a Minimal Supersymmetric Standard Model with an additional $B-L$ gauge symmetry that is spontaneously broken. Charginos and neutralinos with masses between 150 GeV and 1100 GeV are excluded at 95% confidence level for a scenario in which they decay via Higgs bosons, assuming equal decay branching fractions to each lepton flavor. Additional limits are derived for flavor-specific decay scenarios.