Tau signals of R-parity breaking at LEP 200

• Published in: Nuclear physics. B 1993-07, Vol.401 (1), p.67-92
• Main Authors: Godbole, Rohini M., Roy, Probir, Tata, Xerxes
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Physics; Specific theories and interaction models; particle systematics; The physics of elementary particles and fields; Unified field theories and models
• ISSN: 0550-3213; 1873-1562
• DOI: 10.1016/0550-3213(93)90298-4

The detectability at LEP 200 of explicit R-parity breaking by tau-number ( L τ ) violating operators is considered. The assumption of L τ -violation is motivated by the relative lack of constraints on such coupling but similar considerations apply to explicit L e or L μ -violation. The LSP, now unstable, and not necessarily neutral, decays via L τ -violating modes. Only signals from the production and decays of LSP pairs are considered, thereby avoiding any dependence on the sparticle mass spectrum. Rather spectacular signals are predicted: spherical events with m leptons (usually containing at least one τ) and n jets ( m, n ⩽ 4), the most characteristic of which are like-sign ττ events. These signals are enumerated for each LSP candidate and quantitative estimates are provided for the favoured case when the LSP is a neutralino. Other new physics signals, which can mimic these signatures, are also briefly discussed.