Measurement of the Tau Lepton Polarisation at LEP2

A first measurement of the average polarisation P_tau of tau leptons produced in e+e- annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value P_tau = -0.164 +/- 0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV.A first measurement of the average polarisation Pτ of tau leptons produced in e + e − annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value Pτ=−0.164±0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV.A first measurement of the average polarisation P_tau of tau leptons produced in e+e- annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value P_tau = -0.164 +/- 0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV

Contribution à l'étude des hypernoyaux lourds

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

D-meson production in 800-GeV/c pp Interactions

We report on a study of the inclusive production properties of DD? mesons in pp collisions at 800 GeV/c and compare our results to measurements made at lower energies and to the expectations of the QCD fusion model. © 1988 The American Physical Society.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Inclusive V0 Production in pp Interactions at 12 GeV/c

0info:eu-repo/semantics/nonPublishe

Inclusive charm cross sections in 800 GeV/c p-p interactions

We report a measurement of the inclusive D/D̄ production cross section in 800 GeV/c proton-proton interactions. The experiment used the high resolution bubble chamber LEBC exposed to an 800 GeV/c proton beam at the Fermilab MPS. We obtain σ(D/ D ̄)=59-15+22μb (statistical errors), having analysed 25% of the total data sample. Comparison with 400 GeV/c pp dat a obtained with LEBC at CERN shows a D/D̄ cross section increase by a factor of 1.7-0.5+0.7. This is in good agreement with fusion model calculations. © 1987.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Charm D-meson production in 360 GeV/c pp interactions; comparison with π-p at the same energy

Charm D-meson production in 360 GeV pp interactions has been studied using the high-resolution hydrogen bubble chamber LEBC and the European Hybrid Spectrometer. D-mesons are produced with a differential cross section of the form d2σ dx dpT2δ(1-x)n exp (-apT2), withn=1.8± 0.8 and a=1.1±0.03 GeV/c-2 for the Feynman x and Transverse momentum pT behaviour. The inclusive partle prticle crossssection for D and D̄;measured to be: σ(D/ D ̄) = (56-12 25μb (for all x). The Λc D ̄ cross section can be estimated to be ≈20μb. No strong correlation is observed between DD̄ pairs. The results are compared with results from a study of D-meaon production in 360 GeV/c π-p interactions also using LEBC-EHS. © 1983.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Observation of "elastic" hyperon production by antineutrinos

The production of Λ and Σ0 hyperons by antineutrinos has been observed. These events have been used to estimate the production cross-section on protons. The result is compared with the predictions of the Cabibbo theory for the process νp → μ+Λ. © 1972.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Multiplicity of charged particles in 800 GeV p-p interactions

Results are reported concerning the charged-particle multiplicity distribution obtained in an exposure of the high-resolution hydrogen bubble chamber LEBC to a beam of 800 GeV protons at the Fermilab MPS. This is the first time that such data have been available at this energy. The distribution of the number nch of charged particles produced in inelastic interactions obeys KNO-scaling. The average multiplicity is 〈nch〉 = 10.26±0.15. For nch≥8 the data can be well fitted to a negative binomial. The difference between the overall experimental multiplicity distribution and that resulting from the latter fit is in agreement with the contribution expected from diffractive processes. © 1986.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe