5,265 research outputs found
Flavor-Spin Symmetry Estimate of the Nucleon Tensor Charge
The axial vector and tensor charge, defined as the first moments of the
forward nucleon matrix elements of corresponding quark currents, are essential
for characterizing the spin structure of the nucleon. However, the transversity
distribution and thus the tensor charge decouple at leading twist in deep
inelastic scattering, making them hard to measure. Additionally, the
non-conservation of the tensor charge makes it difficult to predict. There are
no definitive theoretical predictions for the tensor charge, aside from several
model dependent calculations. We present a new approach that exploits the
approximate mass degeneracy of the light axial vector mesons ((1260),
(1235) and (1170)) and uses pole dominance to calculate the tensor
charge. The result is simple in form. It depends on the decay constants of the
axial vector mesons and their couplings to the nucleons, along with the average
transverse momentum of the quarks in the nucleon.Comment: 4 pages, RevTe
The Chiral Odd Nucleon Tensor Charge
Exploiting the phenomenological symmetry of the light axial
vector mesons and using pole dominance, we calculate the flavor contributions
to the nucleon tensor charge.Comment: 6 pages LaTeX with ws-p8-50x6-00.cls (included). To appear in the
proceedings of the 6th workshop on non-perturbative QCD, Paris, June 200
Transversity Properties of Quarks and Hadrons in SIDIS and Drell-Yan
We consider the leading twist -odd contributions as the dominant source of
the azimuthal and transverse single spin asymmetries in SIDIS and dilepton
production in Drell-Yan Scattering. These asymmetries contain information on
the distribution of quark transverse spin in (un)polarized protons. In the
spectator framework we estimate these asymmetries at HERMES kinematics and at
for the proposed experiments at GSI, where an anti-proton beam
is ideal for studying the transversity properties of quarks due to the
dominance of {\em valence} quark effects.Comment: 4 pages, 8 figures. To appear in the proceedings of the XIII
International Workshop on Deep Inelastic Scattering (DIS 2005, Madison
Flavor-Spin Symmetry and the Tensor Charge
Exploiting an approximate phenomenological symmetry of the
light axial vector mesons and using pole dominance, we calculate the flavor
contributions to the nucleon tensor charge. The result depends on the decay
constants of the axial vector mesons and their couplings to the nucleons.Comment: Talk given at 3rd Circum-Pan-Pacific Symposium on High Energy Spin
Physics (SPIN 2001), Beijing, China, 8-13 Oct 200
Novel Transversity Properties in SIDIS
We consider a rescattering mechanism to calculate a leading twist -odd
pion fragmentation function, a candidate for filtering the transversity
properties of the nucleon. We evaluate the single spin azimuthal asymmetry for
a transversely polarized target in semi-inclusive deep inelastic scattering
(for HERMES kinematics) and the double -odd asymmetry in this
framework.Comment: To appear in the proceedings of 8th Conference on the Intersections
of Particle and Nuclear Physics (CIPANP 2003), New York, New York, 19-24 May
200
Novel Azimuthal Asymmetries in Drell Yan and Semi-inclusive Deep Inelastic Scattering
We consider the leading and sub-leading twist -odd and even contributions
to the azimuthal asymmetry in unpolarized dilepton production in
Drell-Yan Scattering. We estimate the contributions' effects at , , and energies in the framework of the
parton model using a quark diquark-spectator model of the nucleon to
approximate the soft contributions.Comment: 6 pages, 4 figure
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