The first search for supersymmetry in events with an experimental signature of one soft, hadronically decaying τ lepton, one energetic jet from initial-state radiation, and large transverse momentum imbalance is presented. These event signatures are consistent with direct or indirect production of scalar τ leptons (τ) in supersymmetric models that exhibit coannihilation between the τ and the lightest neutralino (χ10), and that could generate the observed relic density of dark matter. The data correspond to an integrated luminosity of 77.2 fb-1 of proton-proton collisions at √s =13 TeV collected with the CMS detector at the LHC in 2016 and 2017. The results are interpreted in a supersymmetric scenario with a small mass difference (Δm) between the chargino (χ1±) or next-to-lightest neutralino (χ20), and the χ10. The mass of the τ is assumed to be the average of the χ1± and χ10 masses. The data are consistent with standard model background predictions. Upper limits at 95% confidence level are set on the sum of the χ1±, χ20, and τ production cross sections for Δm(χ1±,χ10)=50 GeV, resulting in a lower limit of 290 GeV on the mass of the χ1±, which is the most stringent to date and surpasses the bounds from the LEP experiments.

Search for Supersymmetry with a Compressed Mass Spectrum in Events with a Soft τ Lepton, a Highly Energetic Jet, and Large Missing Transverse Momentum in Proton-Proton Collisions at √s =13 TeV

Meridiani P.;Amapane N.;Argiro S.;Bellan R.;Bellora A.;Cappati A.;Costa M.;Covarelli R.;Kiani B.;Migliore E.;Monaco V.;Monteil E.;Obertino M. M.;Pacher L.;Pinna Angioni G. L.;Romero A.;Salvatico R.;Sola V.;Solano A.;Soldi D.;Shchelina K.;Rumerio P.;Ravera F.;
2020-01-01

Abstract

The first search for supersymmetry in events with an experimental signature of one soft, hadronically decaying τ lepton, one energetic jet from initial-state radiation, and large transverse momentum imbalance is presented. These event signatures are consistent with direct or indirect production of scalar τ leptons (τ) in supersymmetric models that exhibit coannihilation between the τ and the lightest neutralino (χ10), and that could generate the observed relic density of dark matter. The data correspond to an integrated luminosity of 77.2 fb-1 of proton-proton collisions at √s =13 TeV collected with the CMS detector at the LHC in 2016 and 2017. The results are interpreted in a supersymmetric scenario with a small mass difference (Δm) between the chargino (χ1±) or next-to-lightest neutralino (χ20), and the χ10. The mass of the τ is assumed to be the average of the χ1± and χ10 masses. The data are consistent with standard model background predictions. Upper limits at 95% confidence level are set on the sum of the χ1±, χ20, and τ production cross sections for Δm(χ1±,χ10)=50 GeV, resulting in a lower limit of 290 GeV on the mass of the χ1±, which is the most stringent to date and surpasses the bounds from the LEP experiments.
2020
124
041803
1
19
Sirunyan A.M.; Tumasyan A.; Adam W.; Ambrogi F.; Bergauer T.; Brandstetter J.; Dragicevic M.; Ero J.; Escalante Del Valle A.; Flechl M.; Fruhwirth R.;...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/1762242
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