928 research outputs found
Structure functions in polarized proton-deuteron Drell-Yan processes
Polarized proton-deuteron (pd) Drell-Yan processes are investigated for
studying new spin structure of a spin-1 hadron. Our formalism indicates that
there exist many structure functions: 108 in general and 22 in the \vec
Q_T-integrated case. A naive parton model suggests that at least one of them
should be related to the tensor polarized distributions, which have not been
measured at all. There are some experimental possibilities at FNAL, HERA, and
RHIC to study the polarized pd reactions.Comment: 1+3 pages, LaTeX, espcrc2.sty. Talk at the 7th international workshop
on Deep Inelastic Scattering and QCD, Zeuthen, Germany, April 19-23, 1999. To
be published in Nucl. Phys. B. Complete postscript file is available at
http://www2.cc.saga-u.ac.jp/saga-u/riko/physics/quantum1/structure.html
Email: [email protected]
Studies of parton distributions at a neutrino factory
The determination of parton distribution functions in the nucleon and nuclei
is important for obtaining precise hadron-reaction cross sections, from which
any new exotic signature could be found. We show that a future neutrino factory
could provide important information on the parton distributions. First, a
recent effort concerning the parametrization of nuclear parton distributions is
explained. It suggests that the factory should be important for determining
unknown behavior of valence-quark distributions in nuclei at small . Second,
the facility could be used for understanding nucleon spin structure and isospin
violation in the parton distributions.Comment: 1+3 pages, LaTeX2e, elsart.cls, wrapfig.sty, 1 eps figure. Talk given
at the Third International Workshop on Neutrino Factories based on Muon
Storage Rings (NuFACT'01), May 24 - 30, 2001, Tsukuba, Japan. To be published
in proceedings. Email: [email protected], WWW:
http://hs.phys.saga-u.ac.j
Shadowing Aspects of Nuclear Parton Distributions
Various shadowing aspects of nuclear parton distributions are discussed in a
parton-model framework. We explain existing dependent data of
, then the model is applied to a flavor asymmetry
in a nucleus, to shadowing in valence-quark distributions, and to nuclear
dependence of evolution. First, we find that a finite nuclear distribution could be possible due to nuclear interactions even in
the flavor symmetric case in the nucleon (=0). Second, it is
indicated that valence-quark shadowing could be used for discriminating among
various shadowing models. Third, we find that nuclear dependence of
evolution , which was found by
NMC, is essentially understood by modification of parton distributions in
nuclei. However, higher-twist effects in nuclear interactions could be tested
by studying the details of the nuclear evolution.Comment: 10 pages, LATEX, 5 eps figures. Talk given at the Joint
Japan-Australia Workshop on "Quarks, Hadrons, and Nuclei", Adelaide,
Australia, Nov. 15 - 24, 1995. Complete postscript file including the figures
is available at
ftp://ftp.cc.saga-u.ac.jp/pub/paper/riko/quantum1/saga-he-95.ps.gz or at
http://www.cc.saga-u.ac.jp/saga-u/riko/physics/quantum1/kumano.html Email:
[email protected]
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