Alternative Perspective on Gauged Lepton Number and Implications for Collider Physics

Abstract

A new anomaly-free gauged $U(1{)}_{\ell }$ lepton-number model is studied. Two standard model lepton generations acquire the same but oppositive sign $U(1{)}_{\ell }$ charges, while four exotic chiral leptons cancel the anomalies of the remaining lepton family. We discuss a simplified case which has the universal Yukawa couplings. It agrees with all the experimental constraints and predicts $m_e,m_{\mu }\ll m_{\tau }$, and the latter is of the electroweak scale. Due to the interference between the SM and $U(1{)}_{\ell }$ gauge interactions, this model robustly predicts that $e,\mu ,\tau$ have distinctive forward-backward asymmetries at the $e^{+}{e}^{-}$ colliders. It can be searched for at the $e^{+}{e}^{-}$ machine with $\sim$ TeV center-of-mass energy and an integrated luminosity $\sim a{b}^{-1}$.

Comments: 13 pages, 1 figure. Matches published version