Search for Supersymmetry with a Compressed Mass Spectrum in Events with a Soft Lepton, a Highly Energetic Jet, and Large Missing Transverse Momentum in Proton-Proton Collisions at sqrt[s]=13TeV. Academic Article uri icon


  • The first search for supersymmetry in events with an experimental signature of one soft, hadronically decaying 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 leptons ([over ]) in supersymmetric models that exhibit coannihilation between the [over ] and the lightest neutralino ([over ]_{1}^{0}), and that could generate the observed relic density of dark matter. The data correspond to an integrated luminosity of 77.2fb^{-1} of proton-proton collisions at sqrt[s]=13TeV 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 (m) between the chargino ([over ]_{1}^{}) or next-to-lightest neutralino ([over ]_{2}^{0}), and the [over ]_{1}^{0}. The mass of the [over ] is assumed to be the average of the [over ]_{1}^{} and [over ]_{1}^{0} masses. The data are consistent with standard model background predictions. Upper limits at 95%confidence level are set on the sum of the [over ]_{1}^{}, [over ]_{2}^{0}, and [over ] production cross sections for m([over ]_{1}^{},[over ]_{1}^{0})=50GeV, resulting in a lower limit of 290GeV on the mass of the [over ]_{1}^{}, which is the most stringent to date and surpasses the bounds from the LEP experiments.

published proceedings

  • Phys Rev Lett

author list (cited authors)

  • Sirunyan, A. M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Brandstetter, J., ... CMS Collaboration.

publication date

  • January 1, 2020 11:11 AM