Search for nearly mass-degenerate higgsinos using low-momentum mildly-displaced tracks in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector

The ATLAS collaboration
Phys.Rev.Lett. 132 (2024) 221801, 2024.

Abstract (data abstract)
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 $\mathcal{O}$(1 GeV). 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 140 fb$^{-1}$ of proton-proton collision data at $\sqrt{s}$ = 13 TeV 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 GeV to 0.9 GeV is excluded at 95% confidence level, with a maximum reach of approximately 170 GeV in the higgsino mass.

SerializedLikelihoods.tar.gz

License: CC0

Tarball containing the full likelihoods in the HistFactory JSON format. The background information is stored in the 'bkg_only.json' file, while a set of patches for various signal models is provided in the 'patchset.json' file. A README is included in the archive for further instructions.

Download via DOI: curl -OJLH "Accept: application/x-tar" https://doi.org/10.17182/hepdata.146944.v2/r2

Download