Search for Nearly Mass-Degenerate Higgsinos Using Low-Momentum Mildly Displaced Tracks in Collisions at with the ATLAS Detector
G. Aad (CPPM, Aix-Marseille Université, CNRS/IN2P3, Marseille, France); E. Aakvaag (Department for Physics and Technology, University of Bergen, Bergen, Norway); B. Abbott (Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma, USA); K. Abeling (II. Physikalisches Institut, Georg-August-Universität Göttingen, Göttingen, Germany); N. J. Abicht (Fakultät Physik, Technische Universität Dortmund, Dortmund, Germany); et al - Show all 2908 authors
Higgsinos with masses near the electroweak scale can solve the hierarchy problem and provide a dark matter candidate, while detecting them at the LHC remains challenging if their mass splitting is . This Letter presents a novel search for nearly mass-degenerate Higgsinos in events with an energetic jet, missing transverse momentum, and a low-momentum track with a significant transverse impact parameter using of proton-proton collision data at collected by the ATLAS experiment. For the first time since LEP, a range of mass splittings between the lightest charged and neutral Higgsinos from 0.3 to 0.9 GeV is excluded at 95% confidence level, with a maximum reach of approximately 170 GeV in the Higgsino mass.
