Neutrinoless double beta decay and lepton number violation at the LHC
Abstract
We compare the discovery potential of the LHC for lepton number violating (LNV) signals with the sensitivity of current and future double beta decay experiments, assuming 0ββ decay is dominated by heavy particle exchange. We consider charged scalar, leptoquark and diquark mechanisms of 0ββ-decay, covering the 0ββ-decay operators with both, the smallest and largest, possible rates. We demonstrate, if 0ββ-decay were found with a half-life below 1026-1027 ys a positive signal should show up at the LHC, except for some particular cases of the leptoquark mechanism, and vice versa, if the LHC does not find any hints for LNV, a "short-range" explanation for a finite 0ββ-decay half-life will be ruled out in most cases. We argue, if a positive LNV signal were found at the LHC, it is possible to identify the dominant contribution to 0ββ. Two different kinds of observables which could provide such "model discriminating" power are discussed: Different invariant mass peaks and the charge asymmetry.