B. McLeod

Cross-sections for Neutrino Production of Charmed Particles

Abstract We have found 122 charmed-particle decays among 3855 neutrino interactions located in the fiducial volume of a hybrid emulsion spectrometer installed in the Fermilab wide-band neutrino beam. We obtain an average relative charmed-particle production cross section of σ(ν μ → c μ − ) σ(ν μ →μ − ) =4.9 −0.6 +0.7 % , at an average neutrino energy of 22 GeV. We also obtain a production rate of σ(ν μ → c c ν μ ) σ(ν μ →ν μ ) =0.13 −0.11 +0.31 % , if we assume that there was an undetected muon, a limit of σ(ν μ → c c μ − ) σ(ν μ → c μ − ) CL ) can be obtained. Other cross section ratios and limits are also presented.

Measurement of the D+, F+, and Lambda(c)+ Charmed Particle Lifetimes

From the analysis of 685 neutrino and antineutrino interactions in an emulsion target, fifteen candidates for the multiprong decay of charged charmed particles are found. This Letter presents liketimes for the D/sup + -/, F/sup + -/, and ..lambda../sub c//sup +/ states based on the fitted events of the sample.

Charmed hadron production by neutrinos

Abstract Charmed hadron production has been studied using a hybrid emulsion spectrometer in the Fermilab wide-band neutrino beam. The relative rates of D0, D+, F+, and Λ+c production have been measured - the fraction of D mesons is 69 ± 8 10 % . Momentum, transverse momentum, Feynman X, and fragmentation (Z) distributions are presented. The mean Z for charmed hadrons is 0.59 ± 0.03 (±0.03). Charmed target fragments have been observed.

Production characteristics of charmed particles in neutrino interactions

Abstract Using a hybrid emulsion spectrometer installed in the Fermilab wide-band neutrino beam, we located a total of 3855 neutrino interactions in the fiducial volume of our target. For 122 charmed-particle decays found in these interactions, we present distributions of x , y , charm-muon angular projection, Feynman- X , and the fragmentation Z . We find that the number of strange quarks in the nucleon sea is 4.2±2.1±2.6% of the number of down quarks.

Cross sections for charm production by neutrinos

The production of charmed particles has been measured using a hybrid emulsion spectrometer in the Fermilab wide-band neutrino beam. The relative cross section for charged current charmed particle production is σ(v → μ−c)/σ(v → μ−) = 6.5 ±1.91.8%, and the energy dependence of the cross section is presented. One event with charm pair production was observed. A limit of σ(v → μcc)/σ(v → μc) < 6% (90% CL) is found for the ratio of charged current pair and single charm production.

Measurement of D+, F+, and c+ charmed-particle lifetimes

From the analysis of 685 neutrino and antineutrino interactions in an emulsion target, fifteen candidates for the multiprong decay of charged charmed particles are found. This Letter presents liketimes for the D/sup + -/, F/sup + -/, and ..lambda../sub c//sup +/ states based on the fitted events of the sample.

Measurement ofD+,F+, andΛc+Charmed-Particle Lifetimes

From the analysis of 685 neutrino and antineutrino interactions in an emulsion target, fifteen candidates for the multiprong decay of charged charmed particles are found. This Letter presents liketimes for the D/sup + -/, F/sup + -/, and ..lambda../sub c//sup +/ states based on the fitted events of the sample.