Neutrino dipole moments and charge radii in noncommutative space-time

Abstract

In this paper we obtain a bound $\Lambda_{\rm NC} < 150$ TeV on the scale of space-time noncommutativity considering photon-neutrino interactions. We compute "star-dipole moments" and "star-charge radii" originating from space-time noncommutativity and compare them with the dipole moments calculated in the neutrino-mass extended standard model (SM). The computation depends on the nature of the neutrinos, Dirac versus Majorana, their mass and the energy scale. We focus on Majorana neutrinos. The "star-charge radius" is found to be $r^* = \sqrt{|< r^2_{\nu}>_{\rm NC}|} =|3\sum_{i=1}^3 ({\theta}^{0i})^2|^{1/4} < 1.6 \times 10^{-19}$ cm at $\Lambda_{\rm NC} = 150$ TeV.