Exploring NSI degeneracies in long-baseline experiments

L J Flores,O G Miranda,E A Garcés

doi:10.1103/physrevd.98.035030

Abstract

One of the main purposes of long-baseline neutrino experiments is to unambiguously measure the CP violating phase in the neutrino sector within the three neutrino oscillation picture. In the presence of physics beyond the Standard Model, the determination of the CP phase will be more difficult, due to the already known degeneracy problem. Working in the framework of non-standard interactions (NSI), we compute the appearance probabilities in an exact analytical formulation and analyze the region of parameters where the confusion problem is present. We also discuss some cases where the falsification of the NSI parameters can be done in long-baseline experiments.

Highlights

Most of the Standard Model parameters in the leptonic sector have been measured with high precision, including most of the mixing angles of the Pontecorvo-MakiNakagawa-Sakata matrix [1,2,3,4] and the charged lepton masses [5]
The presence of new physics leads naturally to a degeneracy on the neutrino CP phases; for instance, nonunitarity of the leptonic mixing matrix [18,19,20,21] will lead to an ambiguity in the measurement of the standard CP violating phase, δ, as has been already pointed out in [22]
We introduce an analysis of the exact analytical formulas and will obtain useful information to search for the regions leading to a degeneracy of the standard CP violating phase, δ, with the nonstandard interactions (NSI) parameters

Summary

INTRODUCTION

Most of the Standard Model parameters in the leptonic sector have been measured with high precision, including most of the mixing angles of the Pontecorvo-MakiNakagawa-Sakata matrix [1,2,3,4] and the charged lepton masses [5]. Coherent elastic neutrino nucleus scattering [32] has been helpful in obtaining these restrictions [33,34,35,36], as had been foreseen in [37] In this context, the sensitivity to NSI in the future DUNE experiment [6] has been extensively studied [38,39,40,41,42] in order to know the expectative constraints in the future. We introduce an analysis of the exact analytical formulas and will obtain useful information to search for the regions leading to a degeneracy of the standard CP violating phase, δ, with the NSI parameters. It will be evinced that biprobability plots can be used to search for these regions, in this case expectations are more limited

NONSTANDARD INTERACTIONS IN MATTER

U Ãμi i exp

NSI EFFECTS IN LONG-BASELINE EXPERIMENTS

CONCLUSIONS