General search for supersymmetric particles in scenarios with compressed mass spectra using proton-proton collisions at $\sqrt{s}$ = 13 TeV

TL;DR

This paper reports a comprehensive search for supersymmetric particles with compressed mass spectra in proton-proton collisions at 13 TeV, using the CMS detector, setting new mass limits and extending sensitivity to higher sparticle masses.

Contribution

It introduces a generalized search strategy for compressed supersymmetric spectra at the LHC, covering a wide range of sparticle signatures and improving mass exclusion limits.

Findings

No significant excess over background observed.

Mass limits set at 95% CL: 325 GeV for electroweakinos, 275 GeV for sleptons, 780 GeV for top squarks.

Enhanced sensitivity to compressed spectra compared to previous searches.

Abstract

A general search is presented for supersymmetric particles (sparticles) in scenarios featuring compressed mass spectra using proton-proton collisions at a center-of-mass energy of 13 TeV, recorded with the CMS detector at the LHC. The analyzed data sample corresponds to an integrated luminosity of 138 fb$^{-1}$. A wide range of potential sparticle signatures are targeted, including pair production of electroweakinos, sleptons, and top squarks. The search focuses on events with a high transverse momentum system from initial-state-radiation jets recoiling against a potential sparticle system with significant missing transverse momentum. Events are categorized based on their lepton multiplicity, jet multiplicity, number of b-tagged jets, and kinematic variables sensitive to the sparticle masses and mass splittings. The sensitivity extends to higher parent sparticle masses than previously probed at the LHC for production of pairs of electroweakinos, sleptons, and top squarks with mass spectra featuring small mass splittings (compressed mass spectra). The observed results demonstrate agreement with the predictions of the background-only model. Lower mass limits are set at 95% confidence level on production of pairs of electroweakinos, sleptons, and top squarks that extend to 325, 275, and 780 GeV, respectively, for the most favorable compressed mass regime cases.