Cross sections for lepton- and baryon-number-violating processes from supersymmetry at<i>p</i>-<i>p</i>¯ colliders

Abstract

In the standard minimal low-energy supersymmetric model, superpartners are produced only in pairs and the lightest superpartner is stable. At hadron colliders missing transverse energy is the most important signature for this model. There are two other minimal supersymmetric models: one has lepton-number violation, the other baryon-number violation. In both models superpartners can be singly produced and the lightest superpartner is unstable. At hadron colliders missing transverse energy is a poor signature for these models. However, there are several important signatures. The most spectacular signatures have two charged leptons without jets. There are also events with two or more isolated charged leptons and jets. Superpartner masses may be reconstructed from combinations of lepton-lepton or lepton-jet invariant masses and from jet spectroscopy. Cross sections are presented for the most important single and pair superparticle production mechanisms in p-p\ifmmode\bar\else\textasciimacron\fi{} collisions. Present limits from CERN collider data are given and a variety of signatures, events, and backgrounds at \ensuremath{\surd}s =2 TeV are discussed. For example, Drell-Yan fusion of a single superpartner gives a bump in the cross section for ${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$ pairs or jet pairs with invariant mass at the superpartner mass. Squark pair production could yield events with two jets and two isolated charged leptons. If the lightest superpartner is long lived, it can give rise to secondary vertices or to signatures in stable-particle searches. A run of 10 ${\mathrm{pb}}^{\mathrm{\ensuremath{-}}1}$ at \ensuremath{\surd}s =2 TeV will enable a large region of the parameter space to be explored.