Model-independent search for T violation with T2HK and DUNE

TL;DR

This paper proposes a model-independent method to test T violation in neutrino oscillations by comparing transition probabilities at DUNE and T2HK, requiring precise measurements and good energy resolution.

Contribution

It introduces a novel, model-independent approach to detect T violation in neutrino oscillations using dual-baseline measurements at DUNE and T2HK.

Findings

T violation can be identified if $P_{ u_ o u_e}$ at DUNE is smaller than at T2HK.

Necessary experimental conditions include high statistics, energy resolution better than 10%, and 1% precision in near-detector measurements.

The method is feasible with current or near-future neutrino experiments.

Abstract

We consider the time reversal (T) transformation in neutrino oscillations in a model-independent way by comparing the observed transition probabilities at two different baselines at the same neutrino energy. We show that, under modest model assumptions, if the transition probability $P_{\nu_\mu\to\nu_e}$ around $E_\nu \simeq 0.86$ GeV measured at DUNE is smaller than the one at T2HK the T symmetry has to be violated. Experimental requirements needed to achieve good sensitivity to this test for T violation are to obtain enough statistics at DUNE for $E_\nu \lesssim 1$ GeV (around the 2nd oscillation maximum), good energy resolution (better than 10%), and near-detector measurements with a precision of order 1% or better.