Search for the footprints of new physics with laboratory and cosmic neutrinos

Abstract

Observations of high energy neutrinos, both in the laboratory and from cosmic sources, can be a useful probe in searching for new physics. Such observations can provide sensitive tests of Lorentz invariance violation (LIV), which may be a the result of quantum gravity physics (QG). We review some observationally testable consequences of LIV using effective field theory (EFT) formalism. To do this, one can postulate the existence of additional small LIV terms in free particle Lagrangians, suppressed by powers of the Planck mass. The observational consequences of such terms are then examined. In particular, one can place limits on a class of nonrenormalizable, mass dimension five and six Lorentz invariance violating operators that may be the result of QG.

Testing Lorentz Symmetry Using High Energy Astrophysics Observations

“…We will here consider only one of these consequences, viz., the effect of resulting changes in the kinematics of particle interactions. (A discussion of the effect of LIV on modifying neutrino oscillations may be found in [7].) These changes can modify the threshold energies for particle interactions, allowing or forbidding such interactions [5,6].…”

“…In particular, the effect of LIV can change the kinematics of particle interactions and decays and also the threshold energies for these processes [5,6]. LIV can also modify neutrino oscillations [5,7].…”