Zbosonit

The Z boson is a neutral, massive gauge boson that mediates the weak nuclear force in the Standard Model of particle physics. It is one of the carriers of the electroweak interaction, together with the W bosons, and is responsible for neutral current processes that do not change electric charge. The name Z arises from its role as the neutral carrier, distinguishing it from the charged W bosons.

Key properties of the Z boson include its spin-1 nature and its mass of about 91.1876 GeV, with a total width of roughly 2.495 GeV. As a neutral particle, it couples to fermions through vector and axial-vector components, with coupling strengths determined by the weak mixing angle. These couplings differ between left-handed and right-handed fermions, reflecting the chiral structure of the electroweak interaction.

Production and decay occur in high-energy collisions, especially in proton-proton or proton-antiproton environments. In colliders, Z bosons are primarily produced via quark-antiquark annihilation and can be observed through their decay into fermion-antifermion pairs. About 3.3% of decays go to each charged lepton pair (electron, muon, tau), while decays to quark-antiquark pairs account for the majority of hadronic decays. Neutrino pairs provide invisible decay channels, contributing to the Z width.

Historically, the Z boson was discovered in 1983 at CERN by the UA1 and UA2 experiments. Its precise measurements have played a crucial role in testing the electroweak sector of the Standard Model, including determinations of the weak mixing angle and constraints on possible new physics beyond the Standard Model.