V. J. Stenger

Observation of short-lived particles produced in high energy neutrino interactions

Abstract Examination of a sample of 89 high-energy, neutrino-induced dilepton events produced in the Fermilab 15 ft bubble chamber has resulted in the direct observation of the production and visible semi-leptonic decay of short-lived particles. One charged decay, two neutral decays, and one decay candidate of undetermined charge are found. Assuming these events and the remaining dilepton signal result from D meson decays, we obtain τ D + = 2.5 −1.5 +3.5 × 10 −13 s and τ D 0 = 3.5 −1.7 +3.5 × 10 −13 s, using a maximum likelihood analysis.

Anti‐neutrino‐nucleon Charged Current Interaction Cross Sections Measured by the Fermilab 15′ Ne‐H2 Bubble Chamber in a Dichromatic Beam

Fermilab experiment E388 measurements of antineutrino‐nucleon total charged‐current interaction cross sections are reported for 20 < Eν¯ < 200 GeV. E388 used the Fermilab 15′ Neon (56.5% atomic)‐hydrogen bubble chamber (plus external muon identifier), exposed to the N30 dichromatic beam. E388 ran downstream of the CCFRR experiment E616 in this beam and used the same flux monitoring information. No evidence is seen for any variation of σν¯/Eν¯ in this Eν¯ range. The preliminary average σν¯/Eν¯= [0.30 ± 0.02(stat.)±0.02(sys.)±0.02(flux)] × 10−38 cm2GeV/nucleon, is in good agreement with most other measurements, but 20% below the E616 result presented at this conference.