67 research outputs found
WA92: a fixed target experiment to trigger on and identify beauty particle decays
We describe the detectors and trigger system used in the CERN WA92 experiment. The experiment was designed to study the production and decay of beauty particles from 350 GeV/ interactions in copper and tungsten targets. Charged particle tracking is performed using the Omega spectrometer. Silicon microstrip detectors are used to provide precise tracking information in the region of the production and the decay of heavy-flavoured particles and to trigger on the resulting high impact parameter tracks. The precision of vertex reconstruction corresponds to of the mean B-decay proper lifetime. Lepton and high transverse momentum hadron signals are also used in the trigger, which accepts 29\% of B-decays and rejects 98\% of non-beauty interactions
Observation of vertex factorisation breaking in central pp interactions
Central \pipi events produced in pp interactions are studied in terms of correlations between the outgoing protons. It is observed there is more (770) and \fmeson production in reactions where the outgoing protons %fastest and slowest particles in the laboratory frame are on opposite sides of the beam. This effect is not attributable to the trigger or the experimental acceptance, and suggests that the vertices do not factorise
Measurement of the beauty production cross-section in 350 GeV/c -Cu interactions
Using a sample of triggered events, produced in --Cu interactions at 350~GeV, we have identified 26 beauty events. The estimated background in this sample is events. From these data, assuming a linear A-dependence, we measure a beauty production cross-section integrated over all of nb/N
A kinematical selection of glueball candidates in central production
A study of central meson production as a function of the difference in transverse momentum () of the exchanged particles shows that undisputed mesons are suppressed at small whereas the glueball candidates are enhanced
Untersuchungen zur harten Streuung in Photon-Protonreaktionen im Energiebereich von 65 bis 175 GeV am CERN OMEGA-Spektrometer
Inklusive Photoerzeugung von rho0-, omega- und rho+- Mesonen im Photonenergiebereich von 20 bis 70 GeV
Measurement of the branching fraction and of the decay constant
Using interactions of $350\,\hbox{GeV}/
A study of kinematical correlations between charmed particles produced in -Cu interactions at
A sample of 475 events, in which two charmed-particle decays are observed, is analyzed to determine distributions of two-particle kinematic variables. One charmed particle with is fully reconstructed and the other is at least partially recontructed. The distributions of and are compared with a next-to-leading order QCD calculation
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