1,492 research outputs found
Quarkonium production via recombination
The contrast between model predictions for the transverse momentum spectra of
J/Psi observed in Au-Au collisions at RHIC is extended to include effects of
nuclear absorption. We find that the difference between initial production and
recombination is enhanced in the most central collisions. Models utilizing a
combination of these sources may eventually be able to place constraints on
their relative magnitudes.Comment: Based on invited plenary talk at the 2nd International Conference on
Hard and Electromagnetic Probes of High-Energy Nuclear Collisions, Asilomar,
CA, June 9-16, 2006, to be published in Nucl. Phys.
Lambda polarization and single-spin left-right asymmetry in diffractive hadron-hadron collisions
We discuss Lambda polarization and single-spin left-right asymmetry in
diffractive hadron-hadron scattering at high energies. We show that the
physical picture proposed in a recent Letter is consistent with the
experimental observation that polarization in the diffractive
process, , is much higher than that in the inclusive
reaction, . We make predictions for the left-right asymmetry,
A_N, and for the spin transfer, , in the single-spin process
and suggest further experimental tests of the
proposed picture.Comment: 14 pages, 3 ps-figures. Phys. Rev. D (in press
Hyperon polarization in semi-inclusive deeply inelastic lepton-nucleon scattering at high energy
We calculate the polarizations for different octet hyperons produced in the
current fragmentation regions of the deeply inelastic lepton-nucleon
scatterings and at high energy
using different models for spin transfer in fragmentation processes. The
results show that measurements of those hyperon polarizations should provide
useful information to distinguish between different models in particular the
SU(6) and the DIS pictures used frequently in the literature. We found, in
particular, that measuring the polarization of produced in these
processes can give a better test to the validity of the different spin transfer
models.Comment: 30 pages, 13 figure
Calculation of Chirality Violating Proton Structure Function h(x) in QCD
The twist-two chirality violating proton structure function
measurable in the polarized Drell-Yan process is calculated by means of QCD sum
rules at intermediate , and .Comment: 12 pages + 6 figures , LaTeX, preprint LMU-01-94. a few additions to
the text; the figures have been added as uuencoded fil
Transverse momentum dependence in gluon distribution and fragmentation functions
We investigate the twist two gluon distribution functions for spin 1/2
hadrons, emphasizing intrinsic transverse momentum of the gluons. These
functions are relevant in leading order in the inverse hard scale in scattering
processes such as inclusive leptoproduction or Drell-Yan scattering, or more
general in hard processes in which at least two hadrons are involved. They show
up in azimuthal asymmetries. For future estimates of such observables, we
discuss specific bounds on these functions.Comment: 14 pages, revtex, 7 Postscript figure
Accessing Transversity in Double-Spin Asymmetries at the BNL-RHIC
We give upper bounds for transverse double-spin asymmetries in polarized
proton-proton collisions by saturating the positivity constraint for the
transversity densities at a low hadronic resolution scale. We consider prompt
photon, jet, pion, and heavy flavor production at the BNL Relativistic Heavy
Ion Collider (RHIC). Estimates of the expected statistical accuracy for such
measurements are presented, taking into account the acceptance of the RHIC
detectors.Comment: 15 pages, LaTeX, 2 figures as eps file
Habitat-dependent outdoor recreation and conservation organizations can enable recreational fishers to contribute to conservation of coastal marine ecosystems
Stakeholder engagement is essential to conserve ecosystems and associated biodiversity. Outdoor recreation specialists represent stakeholder groups that often rely on specific healthy ecosystems and have unique incentives to contribute to conservation and stewardship. We introduce the concept of habitat-dependent outdoor recreation conservation organizations (HDORCOs) and their potential to harness outdoor recreation enthusiasm to achieve ecosystem-scale conservation objectives. We identify potential roles for HDORCOs in nurturing pro-environmental attitudes and facilitating stewardship behavior among recreationists, focusing on examples from recreational fishing specialists and coastal marine ecosystems. While HDORCOs have achieved conservation outcomes in a range of settings, transferability across recreational specializations and ecological, cultural, socioeconomic, and governance contexts could remain challenging and potentially requires further development of the HDORCO concept. Communication with HDORCOs is one strategy to enhance engagement of recreationists, stakeholder groups not traditionally associated with pro-environmental behavior, in ecosystem-scale conservation efforts
Q^2-Evolution of Nucleon's Chiral-Odd Twist-3 Structure Function: h_L(x,Q^2)
We investigate the -evolution of the chiral-odd spin-dependent parton
distribution relevant for the polarized Drell-Yan processes.
The results are obtained in the leading logarithmic order in the framework of
the renormalization group and the standard QCD perturbation theory. We
calculate the anomalous dimension matrix for the twist-3 operators for
in the one-loop order. The operator mixing among the relevant twist-3 operators
including the operators proportional to the QCD equations of motion is treated
properly in a consistent scheme. Implications for future experiments are also
discussed.Comment: HUPD-9419, Latex file, 21 pages, 7 figures available on reques
Recent results on GaAs detectors - 137
The present understanding of the charge collection in GaAs detectors with
respect to the materials used and its processing are discussed. The radiation
induced degradation of the charge collection efficiency and the leakage current
of the detectors are summarised. The status of strip and pixel detectors for
the ATLAS experiment are reported along with the latest results from GaAs X-ray
detectors for non-high energy physics applications.Comment: 7 pages. 4 postscript figures + 1 postscript preprint logo + 1 LaTeX
file + 1 style file. Also available at
http://ppewww.ph.gla.ac.uk/preprints/97/05
The proton spin sum rule chiral bag prediction, an update
We reevaluate a quark model prediction using the new QCD evolution function
calculated to the 3 loop order and conclude that this model compares favorably
with the new experimental results.Comment: 10 pages, 2 figures available by request, give fax numbe
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