Multilepton SUSY signals from R - parity violation at the Tevatron

The expected trilepton signals from p¯ p → χ ± 1 χ 0 2 → (χ 0 1 ℓ ± ν)(χ 0 1 ℓ ′+ ℓ ′−) will be converted into hadronically quiet multilepton signals, if the two final χ 0 1 have leptonic R-parity-violating (RPV) decays χ 0 1 → ℓℓ ′ ν. We make illustrative calculations of the acceptance for these spectacular RPV signals, and point out that distinctive multilepton signals are possible even when the R-conserving trilepton signals are blocked by the " spoiler mode " χ 0 2 → h 0 χ 0 1. Other channels such as p¯ p → χ ± 1 χ 0 2 → (χ 0 1 ℓ ± ν)(χ 0 1 νν), p¯ p → χ ± 1 χ 0 1 → (χ 0 1 ℓν)χ 0 1 and p¯ p → χ + 1 χ − 1 → (χ 0 1 ℓ + ν)(χ 0 1 ℓ ′− ν) can also give quiet multileptons from RPV. We investigate these signals in the context of supersymmetric models with radiative electroweak symmetry breaking, using examples in the low-tan β λ t fixed-point region. There is intense interest in searching for signatures of Supersymmetry (SUSY) at the Fer-milab Tevatron p¯ p collider, where the highest present CM energy √ s = 1.8–2 TeV is accessed. An important possibility is the pair production of charginos and neutralinos [1], whose lep-tonic decay modes lead to many promising signatures [2–6]. Recently, much theoretical [3,6] and experimental [7,8] attention has centered on trileptons from the production/decay sequence p¯ p → χ ± 1 χ 0 2 → (χ 0 1 ℓ ± ν)(χ 0 1 ℓ ′+ ℓ ′−). (1) Here χ ± i and χ 0 j are charginos and neutralinos (i, j denote mass ordering) and χ 0 1 is the lightest SUSY particle (LSP); see Figs. 1(a) and 1(b). These trilepton events are distinctively " quiet " (little accompanying hadronic excitation); measurable rates are predicted for interesting ranges of SUSY parameters, but are lost in certain parameter regions e.g. where the " spoiler mode " χ 0 2 → χ 0 1 h is kinematically accessible and suppresses all other χ 0 2 decays (h being the lightest Higgs scalar), or where one of the leptons is constrained to be soft and becomes undetectable [3,6]. The popular scenario above assumes the LSP is stable …