A neutrino window to scalar leptoquarks: from low energy to colliders

TL;DR

This paper investigates how scalar leptoquarks, which couple to neutrinos, can be constrained by various experiments from low energy to collider scales, highlighting the importance of coherent elastic neutrino-nucleus scattering in probing MeV-GeV mass ranges.

Contribution

It provides new constraints on scalar leptoquark masses and couplings using recent COHERENT data and compares these with other experimental bounds, emphasizing the complementarity of different methods.

Findings

COHERENT data sets competitive bounds on scalar leptoquarks.

Coherent elastic neutrino-nucleus scattering is effective for probing MeV-GeV leptoquark masses.

Future detector upgrades can significantly improve these bounds.

Abstract

Leptoquarks are theorized particles of either scalar or vector nature that couple simultaneously to quarks and leptons. Motivated by recent measurements of coherent elastic neutrino-nucleus scattering, we consider the impact of scalar leptoquarks coupling to neutrinos on a few complementary processes, from low energy to colliders. In particular, we set competitive constraints on the typical mass and coupling of scalar leptoquarks by analyzing recent COHERENT data. We compare these constraints with bounds from atomic parity violation experiments, deep inelastic neutrino-nucleon scattering and LHC data. Our results highlight a strong complementarity between different facilities and demonstrate the compelling power of coherent elastic neutrino-nucleus scattering experiments to probe leptoquark masses in the MeV-GeV range. Finally, we also present prospects for improving current bounds with future upgrades of the COHERENT detectors and the planned European Spallation Source.