Neutral current refers to a weak interaction in which the particle involved does not change its charge during the interaction. Charged current, on the other hand, refers to a weak interaction in which the particle involved changes its charge during the interaction.
Neutral current weak interactions involve the exchange of a neutral particle, such as a Z boson, between two particles. Charged current weak interactions involve the exchange of a charged particle, such as a W boson, between two particles.
Neutral current weak interactions contribute to the weak force by allowing particles to interact without changing their charge, thus maintaining the overall electric charge of the system. Charged current weak interactions contribute to the weak force by allowing particles to change their charge, causing the weak force to act on them.
An example of a neutral current weak interaction is the scattering of neutrinos off of matter particles. An example of a charged current weak interaction is beta decay, where a neutron decays into a proton, electron, and neutrino.
Neutral current and charged current weak interactions are both fundamental components of the Standard Model of particle physics. They are described by the electroweak theory, which unifies the electromagnetic and weak forces into a single theory. The discovery of neutral current and charged current weak interactions helped to confirm the validity of the Standard Model.