85 research outputs found
Accessing the nucleon transverse structure in inclusive deep inelastic scattering
We revisit the standard analysis of inclusive Deep Inelastic Scattering off
nucleons taking into account the fact that on-shell quarks cannot be present in
the final state, but they rather decay into hadrons - a process that can be
described in terms of suitable "jet" correlators. As a consequence, a spin-flip
term associated with the invariant mass of the produced hadrons is generated
non perturbatively and couples to the target's transversity distribution
function. In inclusive cross sections, this provides an hitherto neglected and
large contribution to the twist-3 part of the g2 structure function, that can
explain the discrepancy between recent calculations and fits of this quantity.
It also provides an extension of the Burkhardt-Cottingham sum rule, putting
constraints on the small-x behavior of the transversity function, as well as an
extension of the Efremov-Teryaev-Leader sum rule, suggesting a novel way to
measure the tensor charge of the proton.Comment: 10 pages, 3 figures. Extended discussion on small-x transversity
asymptotics. References adde
Hadronization in cold nuclear matter
I review a recently proposed scaling analysis of hadron suppression in Deeply
Inelastic Scattering on nuclear targets measured at the HERMES experiment. The
analysis can distinguish 2 competing explanations for the observed suppression,
namely, quark radiative energy loss with long hadron formation times, and
prehadron nuclear absorption with hadronization starting inside the nucleus.
Experimental data are shown to favor short formation times and prehadron
absorption.Comment: 4 pages, 3 figures, uses elsart.cls. Talk given at "Hard Probes
2006", Asilomar Conference Grounds, Pacific Grove, CA (USA), June 9-16, 200
Nuclear modifications of fragmentation functions and rescaling models
We discuss nuclear modification of fragmentation functions in the context of
the so-called ``rescaling models''. These models implement partial
deconfinement inside nuclei by modifying the fragmentation functions
perturbatively. We apply these models to the analysis of nuclear hadron
production in deep inelastic scattering processes at the HERMES and EMC
experiments.Comment: 6 pages, 3 figures, uses espcrc1.sty. Talk presented at "QCD-N'02",
Ferrara (ITA), April 3rd-6th, 200
Collinear factorization for deep inelastic scattering structure functions at large Bjorken xB
We examine the uncertainty of perturbative QCD factorization for hadron
structure functions in deep inelastic scattering at a large value of the
Bjorken variable xB. We analyze the target mass correction to the structure
functions by using the collinear factorization approach in the momentum space.
We express the long distance physics of structure functions and the leading
target mass corrections in terms of parton distribution functions with the
standard operator definition. We compare our result with existing work on the
target mass correction. We also discuss the impact of a final-state jet
function on the extraction of parton distributions at large fractional momentum
x.Comment: 18 pages, 10 figures; discussion on baryon number conservation
clarifie
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