A first measurement of the interaction cross section of the tau neutrino

TL;DR

This paper reports the first measurement of the tau neutrino interaction cross section, based on data from the DONuT experiment, confirming consistency with the Standard Model predictions.

Contribution

It provides the first experimental determination of the tau neutrino cross section relative to electron and muon neutrinos, using data from Fermilab's 1997 experiment.

Findings

Measured tau neutrino cross section: 0.72 ± 0.24 ± 0.36 × 10^{-38} cm^2 GeV^{-1}

Tau neutrino cross section ratio to electron/muon neutrinos: 1.37 ± 0.35 ± 0.77

Results agree with Standard Model predictions.

Abstract

The DONuT experiment collected data in 1997 and published first results in 2000 based on four observed $\nu_\tau$ charged-current (CC) interactions. The final analysis of the data collected in the experiment is presented in this paper, based on $3.6 \times 10^{17}$ protons on target using the 800 GeV Tevatron beam at Fermilab. The number of observed $\nu_\tau$ CC interactions is 9, from a total of 578 observed neutrino interactions. We calculated the energy-independent part of the tau-neutrino CC cross section ($\nu + \bar \nu$), relative to the well-known $\nu_e$ and $\nu_\mu$ cross sections. The ratio $\sigma(\nu_\tau)$/$\sigma(\nu_{e,\mu})$ was found to be $1.37\pm0.35\pm0.77$. The $\nu_\tau$ CC cross section was found to be $0.72 \pm 0.24\pm0.36 \times 10^{-38}$ cm$^{2}\rm{GeV}^{-1}$. Both results are in agreement the Standard Model.