Antinumu

Antinumu, short for anti-numu, is the antiparticle of the muon neutrino, denoted ν̄μ. It is a neutral lepton and a member of the lepton family associated with muons. In the Standard Model, it carries muon lepton number Lμ = −1 and interacts only via the weak nuclear force; it does not participate in electromagnetic or strong interactions.

Antinumu is produced in weak decays such as π− → μ− + ν̄μ and in certain muon decays, for example μ+ → e+ + νe + ν̄μ. It is detected primarily through charged-current interactions that produce a positively charged muon, such as ν̄μ + p → μ+ + n, or by observing its neutral-current interactions in suitable detectors. The cross section for ν̄μ interactions is energy dependent and generally smaller than that for its neutrino counterpart, νμ, due to helicity considerations.

In neutrino physics, antinumu participates in flavor oscillations just like νμ, though CP-violation effects can cause differences between neutrino and antineutrino behavior. Measurements involving ν̄μ appearance and disappearance in long-baseline and atmospheric experiments contribute to our understanding of the neutrino mass hierarchy, mixing parameters, and potential signs of new physics. The standard notation for this particle is ν̄μ, while antinumu is a commonly used shorthand in informal contexts.

See also: muon neutrino, neutrino, weak interaction, neutrino oscillation, CP violation.