Characteristic size for the neutrino
Abstract
The possibility of attributing a characteristic size to the neutrino is discussed in the context of the GlashowSalamWeinberg model of the electroweak interactions. We define the electroweak radius by means of the ν_{l}l' scattering amplitude at the oneloop level. This amplitude can be written, in a certain kinematical domain, in terms of only two form factors, which multiply the electromagnetic current and the weak neutral current, respectively. Since the first one does not depend on the properties of the charged lepton l', its derivative gives a suitable measure of the neutrino size. By construction, the electroweak radius so defined is a finite and gaugeindependent quantity of the order 10^{33} cm^{2}, and it gets contributions from the proper neutrino electromagnetic vertex, from the γZ selfenergy, and from part of the box diagrams. We also show explicitly the gauge dependence of the first two contributions.
 Publication:

Physical Review D
 Pub Date:
 March 1985
 DOI:
 10.1103/PhysRevD.31.1091
 Bibcode:
 1985PhRvD..31.1091L
 Keywords:

 14.60.Gh;
 12.10.Ck;
 13.10.+q