leptonselectrons

Leptonselectrons is an informal term used in some discussions of supersymmetry to refer to the charged slepton states, the scalar superpartners of the leptons. In conventional notation, the charged sleptons are the selectron (electron’s superpartner), smuon (muon’s superpartner), and stau (tau’s superpartner), collectively known as sleptons. The term leptonselectrons may denote the full set of these charged slepton states or, more specifically, the mass eigenstates that arise from mixing between left- and right-handed sleptons in each generation.

In most supersymmetric models, each lepton has a corresponding scalar partner. For each generation there are left-handed and right-handed sleptons, which mix to produce two mass eigenstates, commonly denoted ẽ1, ẽ2 for the electron sector, μ̃1, μ̃2 for the muon sector, and τ̃1, τ̃2 for the tau sector. The degree of mixing is influenced by the Yukawa couplings and by parameters of the supersymmetry-breaking sector, with the third generation often showing the largest mixing due to the tau’s relatively large mass. The sleptons interact via electroweak forces and, if R-parity is conserved, the lightest slepton is typically unstable, decaying to a lepton and the lightest supersymmetric particle (often a neutralino), producing characteristic missing energy signatures.

Experimental searches have not observed leptonselectrons or other sleptons. Mass limits depend on the assumed spectrum, but LEP excluded charged sleptons up to near 100 GeV in favorable scenarios, while LHC analyses push limits for first- and second-generation sleptons well into the several hundred GeV range in many model assumptions. Sleptons remain a central target in the experimental exploration of supersymmetry and the mechanism of SUSY breaking.