Searches for R-parity-violating supersymmetry at colliders

Abstract

The search for R-parity-violating supersymmetry at existing colliders is reviewed with emphasis on the sensitivity to the new Yukawa couplings λ, λ′ (inducing lepton-number-violating interactions) and λ″ (inducing baryon-number-violating interactions). One dramatic consequence of the existence any such nonvanishing coupling is the instability of supersymmetric matter. The extent to which this affects the sensitivity to other free parameters of minimal supersymmetric models has been extensively studied at LEP and is briefly reviewed. Given that supersymmetric matter has not been observed yet, and since its existence still cannot be ruled out, we concentrate here on the important question of a possible “discovery” of supersymmetry (if it exists) through the R-parity-violating couplings. The case of resonant production of sleptons viaλ′ and squarks via λ″ at the Tevatron, as well as the case of resonant production of sneutrinos at LEP involving λ, is briefly discussed. A particular emphasis is then put on the case of resonant production of squarks through electron-quark fusion at HERA which involves λ′.