55 research outputs found
Experimental search for muonic photons
We report new limits on the production of muonic photons in the CERN neutrino beam. The results are based on the analysis of neutrino production of dimuons in the CHARM II detector. A CL limit on the coupling constant of muonic photons, is derived for a muon neutrino mass in the range eV. This improves the limit obtained from a precision measurement of the anomalous magnetic moment of the muon by a factor from 8 to 4
Leading-order QCD Analysis of Neutrino-Induced Dimuon Events
The results of a leading-order QCD analysis of neutrino-induced charm production are presented. They are based on a sample of 4111 \numu- and 871 \anumu-induced opposite-sign dimuon events with , , observed in the CHARM~II detector exposed to the CERN wideband neutrino and antineutrino beams. The analysis yields the value of \linebreak the charm quark mass and the Cabibbo--Kobayashi--Maskawa matrix element . The strange quark content of the nucleon is found to be suppressed with respect to non-strange sea quarks by a factor
Leading-order QCD Analysis of Neutrino-Induced Dimuon Events
The results of a leading-order QCD analysis of neutrino-induced charm production are presented. They are based on a sample of 4111 \numu- and 871 \anumu-induced opposite-sign dimuon events with , and , observed in the CHARM~II detector exposed to the CERN wideband neutrino and antineutrino beams. The analysis yields the value of \linebreak the charm quark mass and the Cabibbo--Kobayashi--Maskawa matrix element . The strange quark content of the nucleon is found to be suppressed with respect to non-strange sea quarks by a factor
Measurement of differential cross sections for muon-neutrino electron scattering
We report on a study of the differential cross section dÏ/dy for the processes of elastic ΜΌ- and ΜΌ-electron scattering. The data on which this analysis is based were recorded between 1987 and 1990 with the CHARM II detector in the wide band neutrino beam at the CERN-SPS. For the first time the shapes of these y-distributions have been determined in a model-independent way. A fit to the data yields for the squares of the neutral coupling constants the ratio gR2/gL2=0.60 +/- 0.19 (stat.) +/- 0.09 (syst.)
An electron-hadron separator for digital sampling calorimeters
A fast and effective algorithm for electromagnetic and hadronic shower separation has been developed for the digital sampling calorimeter of the CHARM II experiment. It is based on a generalization of the minimal spanning tree concept and can be easily applied to other existing calorimeters. In this particular application, which requires the highest efficiency for retaining electromagnetic showers, one gets, for 99% efficiency, a rejection factor of the order of 100 for hadronic showers. © 1989.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe
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