antitau

The antitau is the antiparticle of the tau lepton in the Standard Model. It is denoted tau+ and carries electric charge +1e, opposite to the tau−. The antitau has the same mass and lifetime as the tau lepton, with a mass of about 1.776 GeV/c^2 and a mean lifetime of roughly 2.9 × 10−13 seconds. Like the tau, it has spin 1/2 and participates in weak interactions.

As with other antiparticles, the antitau mirrors the decay channels of the tau lepton, with antiparticles appearing in the final state. Typical decays include tau+ → e+ + νe + anti-ντ, tau+ → μ+ + νμ + anti-ντ, or hadronic decays such as tau+ → hadrons + anti-ντ. The branching fractions match those of the tau lepton, with particle content replaced by antiparticles.

Production and detection: antitau leptons are produced in high-energy collisions, most often in tau+ tau− pairs created in electron–positron annihilation or in hadron colliders via Drell–Yan processes and W boson decays. Experimental identification relies on tracking charged decay products, determining their charge, and observing missing energy carried away by neutrinos.

In physics, the antitau serves as a testbed for lepton universality and CPT symmetry, and it is an essential part of tau-lepton phenomenology in collider experiments. The term “antitau” is commonly used interchangeably with “tau-plus.”