Fitting Neutrino Physics with a U(1)_R Lepton Number

TL;DR

This paper explores a supersymmetric model where a continuous R-symmetry identified with Lepton Number allows neutrino masses and mixing to be explained through radiative effects, accommodating recent experimental observations.

Contribution

It demonstrates that R-breaking effects via Anomaly Mediation can generate neutrino masses and mixing without extra particles, unlike gravitational effects which require additional fields.

Findings

Radiative contributions can reproduce observed neutrino masses and mixing.

Large reactor angle consistent with Daya Bay results.

Different R-breaking mechanisms lead to different model requirements.

Abstract

We study neutrino physics in the context of a supersymmetric model where a continuous R-symmetry is identified with the total Lepton Number and one sneutrino can thus play the role of the down type Higgs. We show that R-breaking effects communicated to the visible sector by Anomaly Mediation can reproduce neutrino masses and mixing solely via radiative contributions, without requiring any additional degree of freedom. In particular, a relatively large reactor angle (as recently observed by the Daya Bay collaboration) can be accommodated in ample regions of the parameter space. On the contrary, if the R-breaking is communicated to the visible sector by gravitational effects at the Planck scale, additional particles are necessary to accommodate neutrino data.