Probing Nonstandard Standard Model Backgrounds with LHC Monojets

TL;DR

This paper investigates how monojet events at the LHC can be used to probe nonstandard neutrino interactions, deriving bounds and exploring mediator mass effects, with implications for dark matter and beyond Standard Model physics.

Contribution

It introduces a novel approach to constrain nonstandard neutrino interactions using collider monojet data, including scenarios with light mediators and distinguishing features from dark matter signals.

Findings

Stringent bounds on nonstandard neutrino interactions approaching solar data levels.

Mediator masses in the 100-1000 GeV range yield the strongest collider constraints.

Monojet bounds are weaker for mediators below 30 GeV compared to the contact interaction limit.

Abstract

Monojet events at colliders have been used to probe models of dark matter and extra dimensions. We point out that these events also probe extensions of the Standard Model modifying neutrino-quark interactions. Such nonstandard interactions (NSI) have been discussed in connection with neutrino oscillation experiments. Assuming first that NSI remain contact at LHC energies, we derive stringent bounds that approach the levels suggested by the Boron-8 solar data. We next explore the possibility that the mediators of the NSI can be produced at colliders. The constraints are found to be strongest for mediator masses in the 10^2-10^3 GeV range, with the best bounds above ~ 200 GeV coming from ATLAS and below from CDF. For mediators with masses below 30 GeV the monojet bounds are weaker than in the contact limit. These results also directly apply to light dark matter searches. Lastly, we discuss how neutrino NSI can be distinguished from dark matter or Kaluza-Klein states with charged lepton searches.