2,315 research outputs found
A Selected Bibliography of Topics on Employment Practices
Cornell University is currently funded by the U.S. Department of Education National Institute on Disability and Rehabilitation Research for a four-year Research and Demonstration entitled Improving Employment Practices Covered by Title I of the ADA (Grant # H133A70005). As a part of these efforts, we have done an extensive literature review on topics related to employer practices and the employment provisions of the Americans with Disabilities Act (ADA). This bibliography is the result of these eighteen months of efforts. This publication is available as a print product, and is accessible online at http://www.ilr.cornell.edu. We hope that these resources will be of assistance in helping human resource professionals, employers, providers of vocational rehabilitation services, advocacy organizations, and persons with disabilities and their family members to better employ the ADA in effectively implementing the accommodation process
On the Determination of the Polarized Sea Distributions of the Nucleon
The possibilities to determine the flavor structure of the polarized sea
(antiquark) distributions of the nucleon via vector boson production at high energy polarized hadron--hadron colliders, such as the
Relativistic Heavy--Ion Collider (RHIC), are studied in detail. In particular
the perturbative stability of the expected asymmetries in two representative
models for the (un)broken flavor structure are investigated by confronting
perturbative QCD leading order predictions of the expected asymmetries with
their next--to--leading order counterparts.Comment: 28 pages, LaTe
Spin-Dependent Structure Functions of Real and Virtual Photons
The implications of the positivity constraint, , on the presently unknown spin--dependent
structure function of real and virtual photons are
studied at scales where longitudinally polarized photons dominate
physically relevant cross sections. In particular it is shown how to implement
the physical constraints of positivity and continuity at in NLO
calculations which afford a nontrivial choice of suitable (DIS) factorization
schemes related to and and appropriate boundary
conditions for the polarized parton distributions of real and virtual photons.
The predictions of two extreme `maximal' and `minimal' saturation scenarios are
presented and compared with results obtained within the framework of a simple
quark `box' calculation expected to yield reasonable estimates in the not too
small regions of and .Comment: 33 pages, LaTeX, 12 figure
The jet quenching in high energy nuclear collisions and quark-gluon plasma
e investigate the energy loss of quark and gluon jets in quark-gluon plasma
produced in central Au+Au collisions at RHIC energy. We use the physical
characteristic of initial and mixed phases, which were found in effective
quasiparticle model for SPS and RHIC energy. At investigation of energy loss we
take into account also the production of hot glue at first stage. The energy
loss in expanding plasma is calculated in dominant first order of radiation
intensity with accounting of finite kinematic bounds. We calculate the
suppression of - spectra with moderate high , which is
caused by energy loss of quark and gluon jets. The comparison with suppression
of reported by PHENIX show, that correct quantitative description of
suppression we have only in model of phase transition with decrease of thermal
gluon mass and effective coupling in region of phase transition plasma
into hadrons (at ). However quasiparticle model with increase of
these values at in accordance with perturbative QCD lead to too
great energy loss of gluon and quark jets, which disagrees with data on
suppression of . Thus it is possible with help of hard processes to
investigate the structure of phase transition. We show also, that energy losses
at SPS energy are too small in order to be observable. This is caused in fact
by sufficiently short plasma phase at this energy.Comment: 17 pages, 3 figures, 2 table
Semi-Contained Neutrino Events in MACRO
Updated results are presented of low-energy ()
neutrino interactions observed by the MACRO detector. Two analyses (of
different topologies) are presented; individually, and especially in their
ratio, they are inconsistent with no oscillations and consistent with maximal
mixing at of a few times .Comment: Paper presented at DPF2000, the American Physical Society's Division
of Particles and Fields conferenc
The Kinetic Interpretation of the DGLAP Equation, its Kramers-Moyal Expansion and Positivity of Helicity Distributions
According to a rederivation - due to Collins and Qiu - the DGLAP equation can
be reinterpreted (in leading order) in a probabilistic way. This form of the
equation has been used indirectly to prove the bound
between polarized and unpolarized distributions, or positivity of the helicity
distributions, for any . We reanalize this issue by performing a detailed
numerical study of the positivity bounds of the helicity distributions. To
obtain the numerical solution we implement an x-space based algorithm for
polarized and unpolarized distributions to next-to-leading order in ,
which we illustrate. We also elaborate on some of the formal properties of the
Collins-Qiu form and comment on the underlying regularization, introduce a
Kramers-Moyal expansion of the equation and briefly analize its Fokker-Planck
approximation. These follow quite naturally once the master version is given.
We illustrate this expansion both for the valence quark distribution and
for the transverse spin distribution .Comment: 38 pages, 27 figures, Dedicated to Prof. Pierre Ramond for his 60th
birthda
Uncertainties of the CJK 5 Flavour LO Parton Distributions in the Real Photon
Radiatively generated, LO quark (u,d,s,c,b) and gluon densities in the real,
unpolarized photon, calculated in the CJK model being an improved realization
of the CJKL approach, have been recently presented. The results were obtained
through a global fit to the experimental F2^gamma data. In this paper we
present, obtained for the very first time in the photon case, an estimate of
the uncertainties of the CJK parton distributions due to the experimental
errors. The analysis is based on the Hessian method which was recently applied
in the proton parton structure analysis. Sets of test parametrizations are
given for the CJK model. They allow for calculation of its best fit parton
distributions along with F2^gamma and for computation of uncertainties of any
physical value depending on the real photon parton densities. We test the
applicability of the approach by comparing uncertainties of example
cross-sections calculated in the Hessian and Lagrange methods. Moreover, we
present a detailed analysis of the chi^2 of the CJK fit and its relation to the
data. We show that large chi^2/DOF of the fit is due to only a few of the
experimental measurements. By excluding them chi^2/DOF approx 1 can be
obtained.Comment: 28 pages, 8 eps figures, 2 Latex figures; FORTRAN programs available
at http://www.fuw.edu.pl/~pjank/param.html; table 10, figure 10 and section 6
correcte
Full Carbon Account for Russia.
The Forestry Project (FOR) at IIASA has produced a full carbon account (FCA) for Russia for 1990, together with scenarios for 2010. Currently, there are rather big question marks regarding the existing carbon accounts for Russia, and Russia is critical to the global carbon balance due to its size. IIASA is in a position to perform solid analysis of Russia because of the databases that the Institute has built over the years. FOR based this work on a comprehensive geographic information system comprising georeferenced descriptions of the environment and land of Russia, which in turn are based on a number of thematic, digitized maps and databases. For the Russian energy sector and other industrial sectors (except the forest industry), the project used emissions estimates from the recent IIASA study "Global Energy Perspectives" (1998). The project carried out a separate substudy for the Russian forest industry sector. According to FOR's estimate, the total fluxes (including energy and industry sectors) in Russia were a net source of 527 teragrams of carbon (Tg C) in 1990. To illustrate the possible development of the carbon pools and fluxes over the next 10 years, FOR developed three different scenarios for the period 1990-2010, reflecting different assumptions regarding Russia's GDP growth. According to these scenarios, Russia will continue to be a net source of carbon to the atmosphere with 156-385 Tg C in 2010, including the emissions from energy and other industrial sectors. However, analysis of the FCA also shows considerable uncertainties involved in the carbon accounting. These uncertainties exceed the calculated changes in the full flux balance for the period 1990-2010. At present, this raises grave questions regarding the reliability of any accounting system used to measure terrestrial ecosystems for compliance with the Kyoto Protocol.
- …