Probing the matter term at long baseline experiments

TL;DR

This paper analyzes how matter effects influence muon to electron neutrino oscillations in long baseline experiments, emphasizing the importance of multiple experiments with different baselines to detect these effects.

Contribution

It demonstrates the impact of Earth's matter on neutrino oscillations and highlights the necessity of multiple baseline experiments to unambiguously identify matter effects.

Findings

Matter effects enhance neutrino oscillations over anti-neutrinos.

Different baseline lengths are required to distinguish matter effects.

Non-zero  mixing angle is implied by oscillation observations.

Abstract

We consider (\nu_\mu --> \nu_e) oscillations in long baseline experiments within a three flavor framework. A non-zero measurement of this oscillation probability implies that the (13) mixing angle `phi' is non-zero. We consider the effect of neutrino propagation through the matter of earth's crust and show that, given the constraints from solar neutrino and CHOOZ data, matter effects enhance the mixing for neutrinos rather than for anti-neutrinos. We need data from two different experiments with different baseline lengths (such as K2K and MINOS) to distinguish matter effects unambiguously.