Quest for new physics using astrophysical neutrino flavor in IceCube

TL;DR

This paper uses IceCube's astrophysical neutrino data to search for signs of new physics beyond the Standard Model by examining neutrino flavor ratios, setting limits on anomalous effects at ultra high energies.

Contribution

It introduces a novel approach to probe Planck scale physics through neutrino flavor analysis, surpassing previous techniques in sensitivity.

Findings

No evidence of flavor anomalies was found.

The method sets new limits on non-standard neutrino interactions.

The approach can probe physics at the Planck scale.

Abstract

We have detected astrophysical neutrinos in IceCube that can be used to probe astrophysical sources at ultra high scales. Here we report a search for anomalous space time effects using astrophysical neutrino flavor data in IceCube. New effective operators are introduced to drive non-standard neutrino flavor mixing which modify the flavor ratios compared to standard cases. Using the High Energy Starting Events sample (HESE) 7.5-year data for this analysis, we found no evidence of such flavor anomalies. However, we are expecting to set limits from this new approach which goes far beyond any known techniques. Importantly, we achieve the necessary precision to probe new physics using neutrino flavor expected by Planck scale theories.