ABSTRACT
We report a measurement of the angular distributions of Drell-Yan dimuons produced using an 800 GeV/c proton beam on a hydrogen target. The polar and azimuthal angular distribution parameters have been extracted over the kinematic range 4.5
ABSTRACT
We report a high statistics measurement of Upsilon production with an 800 GeV/c proton beam on hydrogen and deuterium targets. The dominance of the gluon-gluon fusion process for Upsilon production at this energy implies that the cross section ratio, sigma(p+d-->Upsilon)/2sigma(p+p-->Upsilon), is sensitive to the gluon content in the neutron relative to that in the proton. Over the kinematic region 0
ABSTRACT
We report a measurement of the angular distributions of Drell-Yan dimuons produced using an 800 GeV/c proton beam on a deuterium target. The muon angular distributions in the dilepton rest frame have been measured over the kinematic range 4.5Subject(s)
Mesons
, Protons
, Deuterium
, Elementary Particle Interactions
, Models, Theoretical
, Motion
, Nuclear Physics
ABSTRACT
We present measurements of the polarization of the J/psi produced in 800-GeV proton interactions with a copper target. Polarization of the J/psi is sensitive to the ccmacr; production and hadronization processes. A longitudinal polarization is observed at large x(F), while at small x(F) the state is produced essentially unpolarized or slightly transversely polarized. No significant variation of the polarization is observed versus p(T).
ABSTRACT
Authors examine the influence of metal implants on the distribution of ionizing radiation in tissue. In vivo measurements in a patient are seldom possible. The risk can be assessed with sufficient accuracy on the basis of various experimental dosimetric methods, histological changes in the irradiated volume and the tolerance to the physical stress, published in the available literature. The analysis shows that the risk of significant dose inhomogeneity or the treatment toxicity is minimal if mentioned principles are adhered to. Radiotherapy indications and dosage should not be markedly changed on the basis of the presence of metal in the irradiated volume.
Subject(s)
Metals , Orthopedic Fixation Devices , Prostheses and Implants , Radiotherapy/adverse effects , Humans , Osteoradionecrosis/etiology , Radiation Dosage , Radiometry , Risk FactorsABSTRACT
We present a measurement of the polarization observed for bottomonium states produced in p-Cu collisions at square root of s = 38.8 GeV. The angular distribution of the decay dimuons of the Upsilon(1S) state shows no polarization at small values of the fractional longitudinal momentum x(F) and transverse momentum p(T) but significant positive transverse production polarization for either p(T)>1.8 GeV/c or for x(F)>0.35. The Upsilon(2S+3S) (unresolved) states show a large transverse production polarization at all values of x(F) and p(T) measured. These observations challenge NRQCD calculations of the polarization expected in the hadronic production of bottomonium states.
