Heavy neutral leptons in effective field theory and the high-luminosity LHC

Abstract

Heavy neutral leptons (HNLs) with masses around the electroweak scale are expected to be rather long-lived particles, as a result of the observed smallness of the active neutrino masses. In this work, we study long-lived HNLs in $N_R$SMEFT, a Standard Model (SM) extension with singlet fermions to which we add non-renormalizable operators up to dimension-6. Operators which contain two HNLs can lead to a sizable enhancement of the production cross sections, compared to the minimal case where HNLs are produced only via their mixing with the SM neutrinos. We calculate the expected sensitivities for the ATLAS detector and the future far-detector experiments: AL3X, ANUBIS, CODEX-b, FASER, MATHUSLA, and MoEDAL-MAPP in this setup. The sensitive ranges of the HNL mass and of the active-heavy mixing angle are much larger than those in the minimal case. We study both, Dirac and Majorana, HNLs and discuss how the two cases actually differ phenomenologically, for HNL masses above roughly 100 GeV.

v1, 36 pages, 9 figures, 2 tables, and 2 appendices; v2, minor changes, accepted for publication in JHEP

References in corpus (24)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• An Introduction to PYTHIA 8.2
• FeynRules - Feynman rules made easy
• Automatic spin-entangled decays of heavy resonances in Monte Carlo simulations
• SARAH 3.2: Dirac Gauginos, UFO output, and more
• How bright is the proton? A precise determination of the photon parton distribution function
• A facility to Search for Hidden Particles (SHiP) at the CERN SPS
• Heavy Majorana Neutrinos in the Effective Lagrangian Description: Application to Hadron Colliders
• Right-handed neutrino magnetic moments
• Heavy Majorana Neutrinos from $W\gamma$ Fusion at Hadron Colliders
• Quasi-Dirac neutrinos at the LHC
• Operator Bases in Effective Field Theories with Sterile Neutrinos: $d\le 9$
• Revisiting cosmological bounds on sterile neutrinos
• Broadening the Higgs Boson with Right-Handed Neutrinos and a Higher Dimension Operator at the Electroweak Scale
• General neutrino interactions with sterile neutrinos in light of coherent neutrino-nucleus scattering and meson invisible decays
• Heavy Neutrinos and the Kinematics of Tau Decays
• Majorana neutrinos production at LHeC in an effective approach
• One-loop running of dimension-six Higgs-neutrino operators and implications of a large neutrino dipole moment
• Master Majorana neutrino mass parametrization
• The see-saw portal at future Higgs Factories
• Leptonic anomalous magnetic moments in $\nu$SMEFT
• Experimental Constraints on Higgs Boson Decays to TeV-scale Right-Handed Neutrinos
• Anomalous dimensions from Yukawa couplings in SMNEFT: four-fermion operators
• Displaced Neutrino Jets at the LHeC

Cited by in corpus (15)

• The Forward Physics Facility: Sites, Experiments, and Physics Potential
• The Present and Future Status of Heavy Neutral Leptons
• Long-lived Sterile Neutrinos at Belle II in Effective Field Theory
• Probing right-handed neutrinos dipole operators
• Long-lived heavy neutral leptons at the LHC: four-fermion single-$N_R$ operators
• Assessment of the Dimension-5 Seesaw Portal and Impact of Exotic Higgs Decays on Non-Pointing Photon Searches
• Leptonic anomalous magnetic moments in $\nu$SMEFT
• Long-lived heavy neutral leptons from mesons in effective field theory
• The see-saw portal at future Higgs factories: the role of dimension six operators
• Re-examining $N_R$-EFT Upto Dimension Six
• Lepton collider probes for Majorana neutrino effective interactions
• Enhanced long-lived dark photon signals at lifetime frontier detectors
• Displaced Neutrino Jets at the LHeC
• LHC experiments for long-lived particles of the dark sector
• The Forward Physics Facility at the High-Luminosity LHC