Search for a Lorentz invariance violation contribution in atmospheric   neutrino oscillations using MACRO data
  Neutrino-induced upward-going muons in MACRO have been analysed in terms of relativity principles violating effects, keeping standard mass-induced atmospheric neutrino oscillations as the dominant source of nu_mu -> nu_tau transitions. The data disfavor these exotic possibilities even at a sub-dominant level, and stringent 90% C.L. limits are placed on the Lorentz invariance violation parameter |Delta v| < 6 * 10^(-24) at sin2theta_v = 0 and |Delta v| < 2.5--5 * 10^(-26) at sin2theta_v = +/-1. These limits can also be re-interpreted as upper bounds on the parameters describing violation of the Equivalence Principle. 
G. Battistoni, Y. Becherini, S. Cecchini, M. Cozzi, H. Dekhissi, L. S.   Esposito, G. Giacomelli, M. Giorgini, G. Mandrioli,...