Eur. Phys. J. C (2023) 83: 493
https://doi.org/10.1140/epjc/s10052-023-11574-z

Regular Article - Theoretical Physics

Collider constraints on electroweakinos in the presence of a light gravitino

¹ Department of Physics, University of Oslo, 0316, Oslo, Norway
² School of Physics and Astronomy, Monash University, 3800, Melbourne, VIC, Australia
³ Department of Physics, Theoretical Particle Physics and Cosmology (TPPC), King’s College London, Strand, WC2R 2LS, London, UK
⁴ SUPA, School of Physics and Astronomy, University of Glasgow, G12 8QQ, Glasgow, UK
⁵ Department of Physics and Astronomy, University College London, Gower St., WC1E 6BT, London, UK
⁶ School of Mathematics and Physics, The University of Queensland, St. Lucia, 4072, Brisbane, QLD, Australia
⁷ Department of Physics, Simon Fraser University, V5A 1S6, Burnaby, BC, Canada
⁸ Department of Physics, School of Mathematics and Physics, Xi’an Jiaotong-Liverpool University, 111 Ren’ai Road, Suzhou Dushu Lake, Science and Education Innovation District, Suzhou Industrial Park, 215123, Suzhou, People’s Republic of China
⁹ Institute for Theoretical Particle Physics (TTP), Karlsruhe Institute of Technology (KIT), 76128, Karlsruhe, Germany
¹⁰ Institut de Physique des 2 Infinis de Lyon, Univ Lyon, Univ Lyon 1, CNRS/IN2P3, UMR 5822, 69622, Villeurbanne, France
¹¹ Theoretical Physics Department, CERN, 1211, Geneva 23, Switzerland
¹² Physics and Astronomy Department, University of California, 90095, Los Angeles, CA, USA
¹³ Physikalisches Institut der Rheinischen Friedrich-Wilhelms-Universität Bonn, 53115, Bonn, Germany
¹⁴ Quantum Brilliance Pty Ltd, The Australian National University, Daley Road, 2601, Acton, ACT, Australia
¹⁵ Institute for Theoretical Particle Physics and Cosmology (TTK), RWTH Aachen University, 52056, Aachen, Germany
¹⁶ Department of Physics, ARC Centre of Excellence for Dark Matter Particle Physics & CSSM, University of Adelaide, 5005, Adelaide, SA, Australia
¹⁷ School of Physics, Zhengzhou University, 450000, Zhengzhou, China
¹⁸ Telenor Research, 1360, Fornebu, Norway
¹⁹ CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, 100190, Beijing, China

^m anders.kvellestad@fys.uio.no

Received: 30 March 2023
Accepted: 1 May 2023
Published online: 10 June 2023

Abstract

Using the GAMBIT global fitting framework, we constrain the MSSM with an eV-scale gravitino as the lightest supersymmetric particle, and the six electroweakinos (neutralinos and charginos) as the only other light new states. We combine 15 ATLAS and 12 CMS searches at 13 TeV, along with a large collection of ATLAS and CMS measurements of Standard Model signatures. This model, which we refer to as the $\tilde{G}$-EWMSSM, exhibits quite varied collider phenomenology due to its many permitted electroweakino production processes and decay modes. Characteristic $\tilde{G}$-EWMSSM signal events have two or more Standard Model bosons and missing energy due to the escaping gravitinos. While much of the $\tilde{G}$-EWMSSM parameter space is excluded, we find several viable parameter regions that predict phenomenologically rich scenarios with multiple neutralinos and charginos within the kinematic reach of the LHC during Run 3, or the High Luminosity LHC. In particular, we identify scenarios with Higgsino-dominated electroweakinos as light as 140 GeV that are consistent with our combined set of collider searches and measurements. The full set of $\tilde{G}$-EWMSSM parameter samples and GAMBIT input files generated for this work is available via Zenodo.