Atmospheric neutrinos as a probe of CPT violation

We show that atmospheric neutrinos can provide a sensitive and robust probe of CPT violation (CPTV). We perform realistic event-rate calculations and study the variations of the ratio of total muon to antimuon survival rates with LIE and L (L drop baseline length, E drop neutrino energy) in a detector capable of identifying the muon charge. We demonstrate that measurements of these ratios when coupled with the significant L and E range which characterizes the atmospheric neutrino spectrum provides a method of both detecting the presence of such violations and putting bounds on them which compare very favorably with those possible from a future neutrino factory. (C) 2004 Elsevier B.V. All rights reserved.