Related papers: Proton Spin in Deep Inelastic Scattering
We provide an interpretation of the structure functions of a thermal medium such as the quark-gluon plasma in terms of the scattering of an incoming electron on the medium via the exchange of a spacelike photon. We then focus on the…
The neutron spin structure function, $g_{1n}$, has been of considerable interest recently in connection with the Bjorken sum rule and the proton spin crisis. Work on this problem has concentrated on measurements at low-$x$. We recall the…
We review the theory of polarized structure functions measured in deep-inelastic lepton-nucleon scattering, focusing on the most recent developments. We concentrate on the structure function $g_1$, emphasizing the phenomenological problems…
Within the framework of the so-called "valon" model, we argue that a substantial part of the nucleon spin, about 40%, is carried by the polarized valence quarks. The remaining is the result of cancellations between gluon polarization and…
We discuss bounds on the distribution and fragmentation functions that appear at leading order in deep inelastic 1-particle inclusive leptoproduction or in Drell-Yan processes. These bounds simply follow from positivity of the quark-hadron…
By using the quark-exchange formalism, realistic Faddeev wave functions and Fermi motion effect, we investigate deep inelastic electron scattering from A=3 mirror nuclei in the deep-valence region. The initial valence quarks in put are…
We present the results of our final analysis of the full data set of g_1^p(Q^2), the spin structure function of the proton, collected using CLAS at Jefferson Lab in 2000-2001. Polarized electrons with energies of 1.6, 2.5, 4.2 and 5.7 GeV…
When the new data on polarised lepton nucleon scattering are compared at the same value of $Q^2$ and with a common set of assumptions, a consistent picture of the spin content of the nucleon begins to emerge. Higher order effects in…
A brief overview of various problems related to the description of a polarized proton in quark models is presented. Structure functions are discussed both for longitudinal and transverse polarization. A recently introduced quantity,…
Model independent expressions for all polarization observables in $\mu+p\to \mu+p$ elastic scattering are obtained, taking into account the lepton mass and including the two-photon exchange contribution. The spin structure of the matrix…
The problem of electron-proton scattering is handed over both the elastic and inelastic scattering. Two models are presented in this sense. The first, depends on the multi photon exchange ladder diagram, where the transition matrix is…
We report on a new measurement of the parity-violating asymmetry in quasielastic electron scattering from the deuteron at backward angles at Q2= 0.038 (GeV/c)2. This quantity provides a determination of the neutral weak axial vector form…
Different approaches to describe Compton scattering and the polarizability of the nucleon have been discussed up to now. We show that the most appropriate ones are provided by non-subtracted dispersion theories of the fixed-$t$ and…
In order to obtain polarised parton densities we have made next to leading order QCD fit using experimental data on deep inelastic structure functions on nucleons. This fit is compared with the updated fit to coresponding spin asymmetries.…
A new structure function analysis of CCFR deep inelastic nu-N and nubar-N scattering data is presented for previously unexplored kinematic regions down to Bjorken x=0.0045 and Q^2=0.3 GeV^2. Comparisons to charged lepton scattering data…
Using a simple picture of the constituent quark as a composite system of point-like partons, we construct the polarized parton distributions by a convolution between constituent quark momentum distributions and constituent quark structure…
Of all nuclear physics experiments none are more fundamental than ``elastic'' $p,p$ and, secondarily, $p,d$ or $d,d$ scattering. Recognizing that these particles are themselves composite, ``elastic'' scattering may be accompanied by…
We have made next to leading order QCD fit to the deep inelastic spin asymmetries on nucleons and we determined polarised quark and gluon densities. The functional form for such distributions was inspired by the Martin, Roberts and Stirling…
We determine polarized parton distribution functions (PPDFs) and structure functions from recent experimental data of polarized deep inelastic scattering (DIS) on nuleons at next-to-next-to-leading order (NNLO) approximation in perturbative…
Spin-dependent quark densities, matrix elements of specific density operators in proton states of definite spin-polarization, indicate that the nucleon may harbor an infinite variety of non-spherical shapes. We show that these matrix…