Search

Elastic electron deuteron scattering was measured at the Bonn 2.5 GeV Electron-Synchrotron using a two spectrometer coincidence technique. Data were taken at values of the four momentum transfer squared Q=0.50, 0.60, 0.78, 1.00, and 1.3 (GeV/c) at electron scattering angles θ=77.5° to 139.0° in order to separate the magnetic dipole formfactor F( Q) from the electric formfactor F( Q). Experimental cross sections are compared to theoretical predictions and to measurements of other laboratories. The results indicate that contributions from meson exchange currents are not negligible in this Q region. [ABSTRACT FROM AUTHOR]

We have used the energy-energy angular pattern of hadrons in inelastic muon-deuteron scattering to study perturbative QCD effects and to extract the gluon distribution function ηG( η) of the nucleon, where η is the fractional momentum carried by the gluon. The data were taken with the E665 spectrometer using the Fermilab Tevatron muon beam with a mean beam energy of 490 GeV. We present ηG( η) for 0.005< η<0.05 and at an average Q of 8 GeV using this new technique. We find that ηG( η) in this region can be described by ηG( η) α η with λ=−0.87±0.09( stat.)±( sys.). We compare our results to expectations from various parametrizations of the parton distribution function and also to results from HERA. [ABSTRACT FROM AUTHOR]

The production of charged hadrons is studied in μXe and μD interactions at 490 GeV beam energy. The data were taken at the Tevatron at Fermilab with the E665 spectrometer, equipped with a streamer chamber as vertex detector. Differences between the μXe and μD data are explained by cascading of hadrons in the Xe nucleus. The average multiplicity of charged hadrons in μXe scattering is compared to previously published pXe scattering data and is found to be strongly reduced. This is traced back to the low number of 'projectile' collisions in μXe interactions. From a study of the x dependence of hadron production in μXe scattering, and by considering events with a large rapidity gap, evidence is found for a significant contribution of diffractive scattering, which is enhanced in the kinematic region where shadowing of the cross section is observed. This result supports recent models in which diffractive scattering and nuclear shadowing are closely related. [ABSTRACT FROM AUTHOR]

The production of K, Λ and $$\bar \Lambda $$ particles is studied in the E665 muon-nucleon experiment at Fermilab. The average multiplicities and squared transverse momenta are measured as a function of x and W. Most features of the data can be well described by the Lund model. Within this model, the data on the K/π ratios and on the average K multiplicity in the forward region favor a strangeness suppression factor s/u in the fragmentation process near 0.20. Clear evidence for QCD effects is seen in the average squared transverse momentum of K and Λ particles. [ABSTRACT FROM AUTHOR]

Results on the production of charged hadrons in muon-deuteron and muon-xenon interactions are presented. The data were taken with the E665 spectrometer, which was exposed to the 490 GeV muon beam of the Tevatron at Fermilab. The use of a streamer chamber as vertex detector provides nearly 4π acceptance for charged particles. The μD data are compared with the μXe data in terms of multiplicity distributions, average multiplicities, forward-backward multiplicity correlations, rapidity and transverse momentum distributions and of two-particle rapidity correlations of charged hadrons. The data cover a range of invariant hadronic masses W from 8 to 30 GeV. [ABSTRACT FROM AUTHOR]