PS09 Neutrino Properties and Oscillations
The effective neutrino charge radius
Departamento de Física Teórica and IFIC, Universidad de Valencia-CSIC, E-46100, Burjassot, Valencia, Spain
Accepted: 22 October 2003
Published online: 28 October 2003
It is shown that at one-loop order a neutrino charge radius (NCR) may be defined, which is ultraviolet finite, does not depend on the gauge-fixing parameter, nor on properties of the target other than its electric charge. This is accomplished through the systematic decomposition of physical amplitudes into effective self-energies, vertices, and boxes, which separately respect electroweak gauge invariance. In this way the NCR stems solely from an effective proper photon-neutrino one-loop vertex, which satisfies a naive, QED-like Ward identity. The NCR so defined may be extracted from experiment, at least in principle, by expressing a set of experimental electron-neutrino cross-sections in terms of the finite NCR and two additional gauge- and renormalization-group-invariant quantities, corresponding to the electroweak effective charge and mixing angle.
PACS: 13.15.+g Neutrino interactions – 13.40.Gp Electromagnetic form factors
© Società Italiana di Fisica, Springer-Verlag, 2004