Neutral currents

Neutral currents

Exchange currents which carry no electric charge and mediate certain types of electroweak interactions. The discovery of the neutral-current weak interactions and the agreement of their experimentally measured properties with the theoretical predictions were of great significance in establishing the validity of the Weinberg-Salam model of the electroweak forces.

The electroweak forces come in three subclasses: the electromagnetic interactions, the charged-current weak interactions, and the neutral-current weak interactions. The electromagnetic interaction is mediated by an exchanged photon γ. Since the photon carries no electric charge, there is no change in charge between the incoming and the outgoing particles. The charged-current weak interaction is mediated by the exchange of a charged intermediate boson, the W+, and thus, for example, an incoming neutral lepton such as the νμ is changed into a charged lepton, the μ-. In the neutral-current weak interactions, the exchanged intermediate boson, the Z0, carries no electric charge (hence the name neutral-current interaction), and thus, for example, an incident neutral lepton, such as the νμ, remains an outgoing neutral νμ. See Electron, Intermediate vector boson, Lepton, Neutrino, Photon

The neutral-current interactions were experimentally discovered in 1973, and have since been extensively studied, in neutrino scattering processes. Very important information about the properties of the neutral currents have been obtained by studying the interference effects between the electromagnetic and the neutral-current weak interactions in the scattering of polarized electrons on deuterium. Parity-violating effects in atomic physics processes due to the neutral weak currents have been observed, and predicted parity-violating nuclear effects have been searched for. See Elementary particle, Fundamental interactions, Symmetry laws (physics), Weak nuclear interactions

References in periodicals archive ?
The capacitor or resistor blocks DC and very low-frequency GIC while allowing normally small AC neutral currents to pass to ground.
Finding solutions / dimensioning of the supply cable for the reduction of neutral currents.
Selective Reduction of Neutral Currents in Electrical Installations by means of Shunt Active Compensators
A survey of neutral currents in three-phase computer power systems, IEEE Trans.
1973: Discovery of neutral currents at a bubble chamber
Back propagation algorithm is used to classify the neutral currents of the HVDC transformer generated after subjecting various faults such as section to section fault, winding to winding fault and winding to ground fault etc.
As an advanced study of the Standard Model of particle physics, Tenchini and Verzegnassi's textbook explains most of the properties of current reactions, including Flavour Changing Neutral Currents (FCNC) and Neutral Weak Currents.
The NN weak interaction is also the only practical way to study quark-quark neutral currents at low energy.
Parameters Affecting Neutral Currents in the Presence of Harmonics
There is a likelihood that these installations also suffer from other problems such as large neutral currents, appreciable heat generation, significant losses, etc.
1], were motivated by the unusually large sensitivity of the weak pion coupling to neutral currents, i.
pi]], since it is expected to arise primarily from weak neutral currents.