Lepton Number Conservation, Long-lived Quarks and Superweak Bileptonic Decays

Abstract

In the upcoming LHC Run 2, at $\sqrt{s}\sim 13$ TeV, it is suggested to seek unusually charged ($Q=-4/3$ and $+5/3$) quarks with mass $M_Q\sim 3$ TeV which carry lepton number ($L=+2$ and $-2$ respectively) and decay superweakly to a bilepton $Y$ with mass $M_Y\sim 2.5$ TeV and a usual quark. These long-lived decays will have displaced decay vertices and produce a striking final state in $pp$ which contains two separated jets together with two pairs of correlated like-sign charged leptons. Such a process was inaccessible energetically in LHC Run 1 with $\sqrt{s}\sim 8$ TeV. The simplest theoretical explanation is the 331-model which has new physics necessarily below $4$ TeV and which explains the existence of three families by anomaly cancellation.

Comments: 7 pages LaTeX