D. Kuhn

Multiplicity of charged particles in 800 GeV p-p interactions

Abstract 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 n ch of charged particles produced in inelastic interactions obeys KNO-scaling. The average multiplicity is 〈 n ch 〉 = 10.26±0.15. For n ch ⩾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.

Inclusive Charm Cross-Sections in 800-GeV/c p p Interactions

Abstract We report a measurement of the inclusive D/D 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 +22 μ b (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/D cross section increase by a factor of 1.7 −0.5 +0.7 . This is in good agreement with fusion model calculations.

Observation of a fully reconstructed D0D0 pair with long proper lifetimes in a high resolution hydrogen bubble chamber and the European hybrid spectrometer

Abstract In an experiment with 360 GeV/ c π − beam at the CERN SPS using the high resolution hydrogen bubble chamber LEBC and the European Hybrid Spectrometer, an event has been observed of the type π − p → D 0 D 0 + 8 prongs. The fully reconstructed decay modes are D 0 → K − π + π 0 π 0 and D 0 → K + π + π − π − , with all six charged tracks being detected in the spectrometer and all four photons from the π 0 decays detected in the lead glass gamma detection system. The D 0 has momentum 119.0 ± 0.6 GeV/ c , x F = 0.31, length 4.1 ± 0.1 mm and proper lifetime (2.1 ± 0.1) × 10 −13 s. The D 0 has momentum 78.5 ± 0.3 GeV/ c , x F = 0.19, length 7.5 ± 0.1 mm and proper lifetime (5.9 ± 0.1) × 10 −13 s.

Diffractive proteon fragmentation in 16, 32, and 110 GeV/cK−p interactions and the diffractive production of heavy quarks\((s\bar s,c\bar c)\)

AbstractThe inclusive proton diffraction dissociation cross sections in 16, 32, and 110 GeV/cK−p interactions are determined from the spike nearx=1 in the inclusive negative particle spectra and are compared to those obtained inK−p interactions using other selection methods at various energies. The same procedure is applied to events containing aV0 in order to obtain the cross section for diffractive

Polarization ofΛ0 hyperons inK−p interactions

s\bar s

Triple Regge Analysis and Kbar {K} Off-Shell Interactions from p {->} limits K-Lambda at 110 GeV/c

production. While the total cross section for proton diffraction is found to be approximately constant in the energy range studied here, proton diffraction yielding an

Polarization of Lambda 0 hyperons in K - p interactions

s\bar s - pair