D. P. Ciampa

Observation of tau neutrino interactions

Abstract 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.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.

A new upper limit for the tau-neutrino magnetic moment

Abstract Using a neutrino beam in which a ντ component was identified for the first time, the ντ 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 on μντ of 3.9×10−7μB.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.

Ξ− and Ω− polarization from a neutral hyperon beam

Results from Fermilab experiment E‐800 on the polarization of the Θ‐ and Ω‐ produced from polarized and unpolarized neutral hyperon beams. Two methods were used to produce the Θ‐ and Ω‐ particles. One method used polarized neutral hyperon beam produced from 800 GeV protons incident on a Beryllium target which was then spin transfer polarized. The second method used unpolarized neutral hyperon beams, neutral production mode. These methods are described and the polarizations determined are presented. (AIP)

A precise measurement of the non‐leptonic weak decay parameters α and φ in the spin 3/2 decay ω−→Λ0+K−

Experiment E800 at Fermilab using the E800 spectrometer has made a precise measurement of the non‐leptonic weak decay parameters for the spin 3/2 decay, Ω−→Δ°+K−. The paratmeters determined are αδαΩ=0.0126±0.0042, αΩ=0.0196±0.0066, and φπ=−3.4°±10.3°. This measurement of αΩ is nearly four times more precise than the previous world average value of −0.026±0.026 and shows this parameter to be inconsistent with zero. Also, E800 has made the first measurement of φΩ. (AIP)