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

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.Comment: 37 pages, 15 figure

A New Upper Limit for the Tau-Neutrino Magnetic Moment

Using a prompt neutrino beam in which a nu_tau component was identified for the first time, the nu_tau magnetic moment was measured based on a search for an anomalous increase in the number of neutrino-electron interactions. One such event was observed when 2.3 were expected from background processes, giving an upper 90% confidence limit of 3.9x10^-7 Bohr magnetons.Comment: 9 pages; 1 figur

Observation of Tau Neutrino Interactions

The DONUT experiment has analyzed 203 neutrino interactions recorded in nuclear emulsion targets. A decay search has found evidence of four tau neutrino interactions with an estimated background of 0.34 events. This number is consistent with the Standard Model expectation.Comment: 12 pages, 3 figures, PD

Final tau-neutrino results from the DONuT experiment

The DONuT experiment collected data in 1997 and published first results in 2000 based on four observed ντ charged-current (CC) interactions. The final analysis of the data collected in the experiment is presented in this paper, based on 3.6×1017 protons on target using the 800 GeV Tevatron beam at Fermilab. The number of observed ντ CC events is 9 with an estimated background of 1.5 events, from a total of 578 observed neutrino interactions. We calculate the ντ CC cross section as a function of one parameter. Assuming Ds mesons are the sole source for ντ, the energy-independent part of the total CC cross section can be parametrized as σconst(ντ )=2.51n1.52×10-40cm2GeV-1 for n 4, where n is the parameter controlling the longitudinal part of the Ds differential cross section of the form dσ/dxF (1-|xF|)n. The analysis could not distinguish between ντ and ν̄τ. The value of n obtained from Pythia simulations, n=6.1, gives an estimated value of σconst(ντ)=(0.39±0.13±0.13) ×10-38cm2GeV-1. © 2008 The American Physical Society