antimuons

An antimuon is the antiparticle of the muon, symbolized as μ+. It has the same rest mass as the muon, about 105.66 MeV/c^2, and the same spin 1/2, but carries a positive electric charge (+1e) as opposed to the muon's negative charge. In lepton-number terms, it carries muon-number L_μ = -1, since it is the antiparticle of the muon, which has L_μ = +1. Antimuons participate in electromagnetic and weak interactions and gravity, but not the strong interaction.

Antimuons are unstable and decay via the weak interaction with a mean lifetime of about 2.2 microseconds in vacuum. The dominant decay mode is μ+ → e+ + ν_e + anti-ν_μ, with similar charged-current channels for the muon antiparticle as for the muon (the corresponding decay for μ− is μ− → e− + anti-ν_e + ν_μ). Energy distributions of the decay products are continuous due to the three-body final state.

Antimuons are produced in various processes, including decay of positively charged pions (π+ → μ+ ν_μ) and in high-energy particle collisions. In detectors they are identified by their positive charge and track curvature in magnetic fields, as well as by timing and calorimetric signatures consistent with a minimum-ionizing, penetrating particle.

Applications and significance: In particle physics, muon and antimuon beams are used to study weak interactions and neutrino production, and their decays contribute to atmospheric and accelerator-based neutrino fluxes.