Some properties of charmed particles produced in π--nucleus interactions

The azimuthal correlation distribution of 102 charmed-particle pairs observed in the hybrid emulsion experiment WA75 is compared with theoretical predictions. The various pairs - (D-D0), (D-D+), (D0D0) and (D+D0)-all s how, within statistical error, the same azimuthal correlation distribution, demonstrating its independence from the specific nature of the production channel. Among the decays of 150 charged charmed particles and 138 neutral ones seen, higher multiplicities are favoured for hadronic as opposed to semileptonic decays. The data are consistent with the muonic decays of charged D mesons proceeding through the channels (μ±, v, K0) and [μ±, v, K*0(892)], the fraction through K0 being 0.76±0.06. © 1988.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Interpretation of the Nucleon Structure Functions Measured in the Gargamelle SPS Neutrino/Antineutrino Experiment

The non-singlet part of the nucleon structure functions measured in the Q2 range 0.5 to 50 (GeV/c)2 is compared to leading and next-to-leading order QCD predictions. The possible contributions of higher twist and target mass effects are also evaluated. © 1981.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Experimental search for associated gluino production and decay in 350 GeV/cπ- emulsion interactions

A search for direct evidence of the production and subsequent decay of gluinos has been performed in nuclear emulsions. The emulsion stacks were exposed, as part of a large hybrid apparatus, to a beam of 350GeV/cπt- mesons, and events were selected on the basis of a "missing-energy" trigger. The missing-energy signature is expected to be a characteristic feature of events in which gluinos are produced and subsequently decay into hadrons and almost non-interacting photinos. The negative result of this search sets an upper limit to the production cross section of light gluinos. © 1987.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The double associated production of charmed particles by the interaction of 350 GeV/ cπ- mesons with emulsion nuclei

Evidence is reported for the simultaneous production of four charmed particles in interactions induced by 350 GeV/c π- mesons in stacks of nuclear emulsions. The events were found during a search for beauty particles among a sample of about 200 interactions with candidates for charmed particles. The events selected required the presence of at least one muon with a high component of momentum transverse to the beam direction. © 1987.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Observation of muon-neutrino reactions producing a positron and a strange particle

In addition to one previously reported event, a second event, in which a positron is observed together with a strange particle and a negative muon, has been seen in the bubble chamber Gargamelle exposed to the CERN neutrino beam. The level of the background for this type of event is found to be very low. The data strongly indicate the existence of a new type of interaction leading to a charged lepton pair correlated with a strange particle in the final state. The interpretation of these two events in terms of production of a charmed hadron is presented. © 1976.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Neutral pion production by weak neutral currents in neutrino and antineutrino reactions

A study is presented of single πo production in neutrino and antineutrino interactions in Gargamelle filled with freon CF3Br. Limits on the neutral to charged current cross-section ratios Rv=σ(vN→vN′πo)/2 σ(vN→ μ -N′πo) and Rν = σ(νN → νN′πo)/2 σ(νN → ω+N′πo) are found to be 0.10 < Rν < 0.20 and 0.26 < Rν < 0.44 at 68% confidence level. © 1975.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe

High energy electronic neutrino (ve) and antineutrino (ve) interactions

The total cross-sections for ve (ve)-nucleon scattering have been measured. A test has been made of the muon number conservation law. A limit of 2.4 GeV is found the mass of the "Georgi-Glashow type" heavy lepton. © 1973.0SCOPUS: 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

Dilepton and strange particles production by neutrinos in gargamelle

New results are presented of an analysis of pictures taken during an exposure of Gargamelle to the CERN ν beam in 1975. In addition to three νμ+N→μ-+e++V0+ hadrons events previously reported, an excess is found of events of the type νμ+N→μ-+e++ hadrons without V0. An analysis of strange particle production in charged current events suggests a possible violation of the ΔS=ΔQ rule. Interpreted in terms of charm production, the data permit an estimate of branching ratios and production rate of charmed particles. A limit is also placed on charmed particle production by neutral currents. © 1977.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Observation of an e+ p → µ+X Event with High Transverse Momenta at HERA

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