Radiative corrections to the leptonic Dirac CP-violating phase

TL;DR

This paper investigates how radiative corrections affect the leptonic Dirac CP-violating phase delta in neutrino oscillations within certain theoretical models, finding that delta remains stable except under specific conditions.

Contribution

It provides a systematic analysis of the stability of delta against radiative corrections in the MSSM and extra-dimensional models, considering both Majorana and Dirac neutrinos.

Findings

Delta is stable against radiative corrections in most scenarios.

Large tan beta in MSSM can significantly alter delta.

Radiative corrections have minimal impact in the minimal models studied.

Abstract

Since the smallest leptonic mixing angle theta_{13} has been measured to be relatively large, it is quite promising to constrain or determine the leptonic Dirac CP-violating phase delta in future neutrino oscillation experiments. Given some typical values of delta = pi/2, pi, and 3pi/2 at the low-energy scale, as well as current experimental results of the other neutrino parameters, we perform a systematic study of the radiative corrections to delta by using the one-loop renormalization group equations in the minimal supersymmetric standard model and the universal extra-dimensional model. It turns out that delta is rather stable against radiative corrections in both models, except for the minimal supersymmetric standard model with a very large value of tan beta. Both cases of Majorana and Dirac neutrinos are discussed. In addition, we use the preliminary indication of delta = (1.08^{+0.28}_{-0.31}) pi or delta = (1.67^{+0.37}_{-0.77}) pi from the latest global-fit analyses of data from neutrino oscillation experiments to illustrate how it will be modified by radiative corrections.