Abstract

Massive spin-1/2 fields are studied in the framework of loop quantum gravity by considering a state approximating, at a length scale L much greater than Planck length ep, a spin-1/2 field in flat spacetime. The discrete structure of spacetime at ep yields corrections to the field propagation at scale L. Neutrino bursts ((p) over bar approximate to 10(5) GeV) accompanying gamma ray bursts that have traveled cosmological distances L are considered. The dominant correction is helicity independent and leads to a time delay of order ((p) over bar lp)L/c approximate to 10(4) s. To next order in (p) over bar lp, the correction has the form of the Gambini and Pullin effect for photons. A dependence L-os(-1) proportional to (p) over bar(2)lp is found for a two-flavor neutrino oscillation length.