Probing CPT violation in neutrino oscillation: A three flavor analysis

TL;DR

This paper introduces a new method to analyze CPT violation in three-flavor neutrino oscillations with matter effects, providing bounds on CPT-violating parameters using atmospheric neutrino data from a magnetized iron calorimeter detector.

Contribution

A novel approach to incorporate CPT violating terms into neutrino oscillation probability calculations without approximation, and an analysis of CPT violation bounds using atmospheric neutrino data.

Findings

Potential bound of δb_{32} < 6×10^{-24} GeV at 99% CL with 1 Mton.year exposure

No fake CPT violation can be generated by matter effects in atmospheric neutrino experiments

Atmospheric neutrinos can effectively discriminate CPT violation from CP violation and nonstandard interactions

Abstract

We have studied $CPT$ violation in neutrino oscillation considering three flavor framework with matter effect. We have constructed a new way to find the oscillation probability incorporating $CPT$ violating terms without any approximation. Then $CPT$ violation with atmospheric neutrinos for a magnetized iron calorimeter detector considering the muons (directly measurable with high resolution) of the charge current events has been studied for zero and nonzero $\theta_{13}$ values. It is found that a potential bound of $\delta b_{32} \lapp 6\times 10^{-24}$ GeV at 99% CL can be obtained with 1 Mton.year exposure of this detector; and unlike neutrino beam experiments, there is no possibility to generate `fake' $CPT$ violation due to matter effect with atmospheric neutrinos. The advantages of atmospheric neutrinos to discriminate $CPT$ violation from CP violation and nonstandard interactions are also discussed.