Statistical criteria for possible indications of new physics in tritium $\beta$-decay spectrum

TL;DR

This paper develops statistical criteria based on the quasi-optimal weights method to detect potential new physics signals in tritium beta-decay spectra, aiding the analysis of experimental data for anomalies.

Contribution

It introduces quasi-optimal criteria tailored for identifying anomalous contributions in beta-decay spectra, enhancing detection sensitivity for new physics beyond the Standard Model.

Findings

Criteria effectively detect anomalies in simulated spectra.

Application to real experiments demonstrates practical utility.

Criteria outperform traditional methods in sensitivity.

Abstract

The method of quasi-optimal weights is applied to constructing (quasi-)optimal criteria for various anomalous contributions in experimental spectra. Anomalies in the spectra could indicate physics beyond the Standard Model (additional interactions and neutrino flavours, Lorenz violation etc.). In particular the cumulative tritium $\beta$-decay spectrum (for instance, in Troitsk-$\nu$-mass, Mainz Neutrino Mass and KATRIN experiments) is analysed using the derived special criteria. Using the power functions we show that the derived quasi-optimal criteria are efficient statistical instruments for detecting the anomalous contributions in the spectra.