Search for supersymmetry in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV in events with high-momentum Z bosons and missing transverse momentum

Abstract

A search for new physics in events with two highly Lorentz-boosted Z bosons and large missing transverse momentum is presented. The analyzed proton-proton collision data, corresponding to an integrated luminosity of 137 fb−1, were recorded at $$ \sqrt{s} $$ s = 13 TeV by the CMS experiment at the CERN LHC. The search utilizes the substructure of jets with large radius to identify quark pairs from Z boson decays. Backgrounds from standard model processes are suppressed by requirements on the jet mass and the missing transverse momentum. No significant excess in the event yield is observed beyond the number of background events expected from the standard model. For a simplified supersymmetric model in which the Z bosons arise from the decay of gluinos, an exclusion limit of 1920 GeV on the gluino mass is set at 95% confidence level. This is the first search for beyond-standard-model production of pairs of boosted Z bosons plus large missing transverse momentum.

Strong electroweak phase transition in $t$-channel simplified dark matter models

“…[39]). Supersymmetric particles have been intensively searched for at the LHC, and stringent bounds have been put on the mass of the QCD coloured states such as squarks and gluinos [41][42][43][44][45][46]. This pushes the masses of the new states beyond 1 TeV.…”

Status of searches for electroweak-scale supersymmetry after LHC Run 2

“…Likewise, longer gluino decay chains with hadronic vector boson decays may also give rise to final states with higher jet multiplicity [116,117,119,124] or hadronic resonances. A CMS anal-ysis [125], for example, targets full hadronic decays of the Z boson produced in gluino pair production followed by g → q q χ0 2, followed by χ0 2 → Z χ0 1: assuming a χ0 2 mass similar to that of the pair-produced gluino, and a small χ0 1, the Z boson has a large boost, and its decay products can be collected in large-R jets. The event selection is characterised by the requirement of large E miss T and large H T , followed by the requirement of two high-p T jets with R = 0.8, with mass compatible with that of the Z boson.…”

Experimental SUSY overview

“…2, left, middle). Another all hadronic CMS search [11] focuses on˜ decaying to Z bosons incorporating also the next-to-lightest SUSY particle (˜ 0 2 ) while the˜ 0 2 and the˜ 0 1 are mixed states of the neutral Higgs and the gauge bosons. This search has been motivated by scenarios that preserve naturalness (that is the need for a minimal fine tuning of the SM in order to solve the gauge hierarchy problem) by introducing large Δ between the neutralinos and the charginos (˜ ± 1 ), resulting in final states with vector bosons and miss T [12].…”

“…Exclusion limits at 95% CL and ±1 s.d. uncertainty bands from CMS˜ searches[10]-[11]. Left and middle: Interpretation in the T1tttt (left) and the T5tttt models.…”