Cosmology and CPT violating neutrinos

TL;DR

This paper investigates CPT violation in neutrinos by analyzing cosmological data, providing the first bounds on neutrino-antineutrino mass differences and exploring future experimental sensitivities.

Contribution

It introduces the first cosmological bounds on CPT violation in neutrino mass differences and assesses future experiment capabilities.

Findings

Cosmology can constrain CPT violation in neutrino mass differences.

Current Planck and BAO data set bounds on CPT violation.

Future experiments like Euclid could improve these bounds significantly.

Abstract

The combination Charge Conjugation-Parity-Time Reversal(CPT) is a fundamental symmetry in our current understanding of nature. As such, testing CPT violation is a strongly motivated path to explore new physics. In this paper we study CPT violation in the neutrino sector, giving for the first time a bound, for a fundamental particle, in the CPT violating particle-antiparticle gravitational mass difference. We argue that cosmology is nowadays the only data sensitive to CPT violation for the neutrino-antineutrino mass splitting and we use the latest data release from Planck combined with the current Baryonic-Acoustic-Oscillation measurement to perform a full cosmological analysis. To show the potential of the future experiments we also show the results for Euclid, a next generation large scale structure experiment.