Tau (particle) Tau (particle) The tau (τ), also called the tau lepton, tau particle, or tauon, is an elementary particle similar to the electron, with negative electric charge and a spin of. Together with the electron, the muon, and the three neutrinos, it is a lepton. Like all elementary particles with half-integer spin, the tau has a corresponding antiparticle of opposite charge but equal mass and spin, which in the tau's case is the antitau (also called the "positive tau"). Tau particles are denoted by and the antitau by . Tau leptons have a lifetime of and a mass of (compared to
Ida (given name) may refer to: Ida (given name) Ida is a given name occurring independently in several cultures. In Germany, Ida is a female name derived from a Germanic word "id", meaning "labor, work". Alternately, it may be related to the name of the Old Norse goddess "Iðunn". Ida also occurs as an anglicisation of the Irish girl's given name Íde. Ida is a currently popular name in the Nordic countries and is among the top 10 names given to girls born in 2013 in Denmark. It was among the top 20 names for newborn girls in Norway in 2013 and among