Long-lived sterile neutrinos at the LHC in effective field theory

• Published in: The journal of high energy physics Vol. 2021; no. 3; pp. 1 - 55
• Main Authors: de Vries, Jordy, Dreiner, Herbert K., Günther, Julian Y., Wang, Zeren Simon, Zhou, Guanghui
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.03.2021; Springer Nature B.V; SpringerOpen
• Subjects: Apexes; Charm (particle physics); Classical and Quantum Gravitation; Decay; Elementary Particles; Experiments; Field theory; High energy physics; Large Hadron Collider; Luminosity; Mesons; Neutrinos; Operators; Phenomenological Models; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Theoretical Physics; Relativity Theory; Solenoids; String Theory; Phenomenological Models
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP03(2021)148

A bstract We study the prospects of a displaced-vertex search of sterile neutrinos at the Large Hadron Collider (LHC) in the framework of the neutrino-extended Standard Model Effective Field Theory ( ν SMEFT). The production and decay of sterile neutrinos can proceed via the standard active-sterile neutrino mixing in the weak current, as well as through higher-dimensional operators arising from decoupled new physics. If sterile neutrinos are long-lived, their decay can lead to displaced vertices which can be reconstructed. We investigate the search sensitivities for the ATLAS/CMS detector, the future far-detector experiments: AL3X, ANUBIS, CODEX-b, FASER, MATHUSLA, and MoEDAL-MAPP, and at the proposed fixed-target experiment SHiP. We study scenarios where sterile neutrinos are predominantly produced via rare charm and bottom mesons decays through minimal mixing and/or dimension-six operators in the ν SMEFT Lagrangian. We perform simulations to determine the potential reach of high-luminosity LHC experiments in probing the EFT operators, finding that these experiments are very competitive with other searches.