Breaking Local Baryon and Lepton Number at the TeV Scale

TL;DR

This paper proposes models where baryon and lepton numbers are gauged and broken at the TeV scale, using a vector-like fourth generation to cancel anomalies, allowing potential collider signals without rapid proton decay.

Contribution

It introduces simple non-supersymmetric and supersymmetric models with gauged B and L that avoid Landau poles and proton decay, and predicts observable baryon/lepton violation at the LHC.

Findings

Models cancel anomalies with a vector-like fourth generation.

Proton decay is forbidden despite B and L breaking.

Baryon/lepton violation could be observed at the LHC.

Abstract

Simple models are proposed where the baryon and lepton number are gauged and spontaneously broken near the weak scale. The models use a fourth generation that is vector-like with respect to the strong, weak and electromagnetic interactions to cancel anomalies. One does not need large Yukawa couplings to be consistent with the experimental limits on fourth generation quark masses and hence the models are free of Landau poles near the weak scale. We discuss the main features of simple non-supersymmetric and supersymmetric models. In these models the light neutrino masses are generated through the seesaw mechanism and proton decay is forbidden even though B and L are broken near the weak scale. For some values of the parameters in these models baryon and/or lepton number violation can be observed at the Large Hadron Collider.