Photon-neutrino interaction in theta-exact covariant noncommutative   model: Phenomenology and Quantum properties*
  We construct the theta-exact covariant noncommutative (NC) model and obtain various closed constraints on the NC scale (Lambda_NC) from inelastic neutrino-nucleon scatterings (nu N -> nu+X), from plasmon decay into neutrino pair (gamma_pl -> bar nu + nu), from the BBN nucleosynthesis and from the reheating phase after inflation, respectively. We have have found neutrino two-point function in a closed form. It shows decoupling of the UV divergent term from softened UV/IR mixing term and from the finite terms as well. We show that problematic UV divergent and UV/IR mixing terms vanish for a certain choice of the noncommutative parameter theta which preserves unitarity. We find non-perturbative modifications of the neutrino dispersion relations which are assymptotically independent of the scale of noncommutativity in both the low and high energy limits and may allow superluminal propagation. 
Josip Trampetic
hep-ph