Short-range mechanisms of neutrinoless double beta decay at the LHC

TL;DR

This paper investigates short-range mechanisms of neutrinoless double beta decay and their signatures at the LHC, comparing current and future experimental sensitivities and proposing methods to distinguish different mechanisms.

Contribution

It provides the first detailed comparison of LHC and neutrinoless double beta decay sensitivities for short-range LNV mechanisms and suggests new strategies for mechanism discrimination at the LHC.

Findings

LHC will be more sensitive than neutrinoless double beta decay for most mechanisms.

Charge asymmetry in leptons can help identify the underlying LNV mechanism.

Different invariant mass peaks can discriminate among various LNV processes.

Abstract

Lepton number violation (LNV) mediated by short range operators can manifest itself in both neutrinoless double beta decay and in processes with same sign dilepton final states at the LHC. We derive limits from existing LHC data at $\sqrt{s}=8$ TeV and compare the discovery potential of the forthcoming $\sqrt{s}=14$ TeV phase of the LHC with the sensitivity of current and future neutrinoless double beta decay experiments, assuming the short-range part of the decay amplitude dominates. We focus on the first of two possible topologies triggered by one fermion and two bosons in the intermediate state. In all cases, except for the pure leptoquark mechanism, the LHC will be more sensitive than neutrinoless double beta decay in the future. In addition, we propose to search for a charge asymmetry in the final state leptons and to use different invariant mass peaks as a possibility to discriminate the various possible mechanisms for LNV signals at the LHC.