1,222 research outputs found
Cooperative Marketing of Animal Health Products
This report uses eight case studies to identify elements of successful cooperative programs for retailing over-the-counter animal health products (AHP). It provides practical information on AHP marketing strategies and methods for cooperative retailers, planners, and researchers. All participating cooperatives except one provided information for fiscal years ending during calendar year 1986. The exception was for 1987. Information. about five AHP suppliers and their marketing programs is included to enhance understanding of retailer programs.Cooperative, advertising, animal health products, centralized, federated, local, margin, marketing, over-the-counter, Agribusiness, Livestock Production/Industries,
Threshold Resummation for W-Boson Production at RHIC
We study the resummation of large logarithmic perturbative corrections to the
partonic cross sections relevant for the process pp -> W^+- X at the BNL
Relativistic Heavy Ion Collider (RHIC). At RHIC, polarized protons are
available, and spin asymmetries for this process will be used for precise
measurements of the up and down quark and anti-quark distributions in the
proton. The corrections arise near the threshold for the partonic reaction and
are associated with soft-gluon emission. We perform the resummation to
next-to-leading logarithmic accuracy, for the rapidity-differential cross
section. We find that resummation leads to relatively moderate effects on the
cross sections and spin asymmetries.Comment: 25 pages, 15 figures as eps files. One reference added and typo
correcte
Soffer's inequality and the transversely polarized Drell-Yan process at next-to-leading order
We check numerically if Soffer's inequality for quark distributions is
preserved by next-to-leading order QCD evolution. Assuming that the inequality
is saturated at a low hadronic scale we estimate the maximal transverse double
spin asymmetry for Drell-Yan muon pair production to next-to-leading order
accuracy.Comment: 20 Pages, LaTeX, 7 figures as eps file
Transverse Double-Spin Asymmetries for Muon Pair Production in pp-Collisions
We calculate the rapidity dependence of the transverse double-spin asymmetry
for the Drell-Yan process to next-to-leading order in the strong coupling.
Input transversity distributions are obtained by saturating the Soffer
inequality at a low hadronic mass scale. Results for the polarized BNL-RHIC
proton-proton collider and the proposed HERA-N fixed-target experiment are
presented, and the influence of the limited muon acceptance of the detectors on
measurements of the asymmetry is studied in detail.Comment: 7 pages including 5 figures; significantly shortened, to be published
in Phys. Rev.
Low-mass lepton pair production at large transverse momentum
We study the transverse momentum distribution of low-mass lepton pairs
produced in hadronic scattering, using the perturbative QCD factorization
approach. We argue that the distribution at large transverse momentum, , with the pair's invariant mass as low as , can be systematically factorized into universal
parton-to-lepton pair fragmentation functions, parton distributions, and
perturbatively calculable partonic hard parts evaluated at a short distance
scale . We introduce a model for the input lepton pair
fragmentation functions at a scale GeV, which are then evolved
perturbatively to scales relevant at RHIC. Using the evolved fragmentation
functions, we calculate the transverse momentum distributions in hadron-hadron,
hadron-nucleus, and nucleus-nucleus collisions at RHIC. We also discuss the
sensitivity of the transverse momentum distribution of low-mass lepton pairs to
the gluon distribution.Comment: 16 pages, 11 figures, revised version to appear in Phys. Rev.
Polarized semi-inclusive electroweak structure functions at next-to-leading-order
We present a next-to-leading order (NLO) computation of the full set of
polarized and unpolarized electroweak semi-inclusive DIS (SIDIS) structure
functions, whose knowledge is crucial for a precise extraction of polarized
parton distributions. We focus on the phenomenology of the polarized structure
functions for the kinematical conditions that could be reached in an
Electron-Ion-Collider.
We show that the NLO corrections are sizeable, particularly in the small-
range. We test the sensitivity of these structure functions on certain quark
distributions and compare it to the situation of inclusive DIS and
electromagnetic SIDIS.Comment: 17 pages, 5 figure
Direct Photons at RHIC
The PHENIX experiment has measured direct photons in
GeV Au+Au collisions and p+p collisions. The fraction of photons due to direct
production in Au+Au collisions is shown as a function of and centrality.
This measurement is compared with expectation from pQCD calculations. Other
possible sources of direct photons are discussed.Comment: 7 pages, 5 figures, presented at Hot Quarks 2004, Taos, N
Next-to-leading Order Evolution of Transversity Distributions and Soffer's Inequality
We present a calculation of the two-loop splitting functions for the
evolution of the twist-2 `transversity' parton densities of transversely
polarized nucleons. We study the implications of our results for Soffer's
inequality for the case of valence quark densities.Comment: 23 Pages, LaTeX, 2 figures as eps files, final, slightly modified
version, to appear in Phys. Rev.
Drell-Yan forward-backward and spin asymmetries for arbitrary vector boson production at next-to-leading order
Longitudinally polarized, unpolarized and forward-backward mass differential
cross sections for Drell-Yan lepton-pair production by arbitrary vector bosons
are calculated in next-to-leading order (NLO) QCD. Analytical results are
presented in a form valid for all consistent -dimensional regularization
schemes, with the mass factorization scheme kept general. NLO predictions for
all Drell-Yan type processes (, and ) at BNL's
relativistic heavy ion collider (RHIC) are made using polarized parton
distributions which fit the recent deep-inelastic scattering data. These are
examined as tools in the determination of the polarized parton distributions
and the unpolarized ratio. NLO predictions for the
forward-backward lepton asymmetry at Fermilab are made and the precision
determination of from future runs is studied. In all the
above, the QCD corrections are found to be significant. An introductory
discussion is given of various theoretical issues, such as allowable
factorization and regularization schemes, and scale dependences.Comment: 34 pages, figures included, revtex. Some discussions and references
added/modified. In more compact form. To appear in Phys. Rev.
- …
