Related papers: Featuring the structure functions geometry
The implications of the positivity constraint on the presently unknown polarized structure function of the photon, $g_1^{\gamma}(x,Q^2)$, are studied in detail. In particular the non-trivial consequences of this constraint,…
Several examples for the role of orbital angular momentum and spin-orbit correlations in hadron structure are discussed.
Quark mass effects are included in the calculation of polarized structure functions. In particular, the validity of fixed order perturbation theory and of massless evolution is studied in the framework of heavy quarks structure functions.…
Some nonperturbative aspects of spin studies at RHIC are discussed and the predictions for single- and two-spin asymmetries are given. Among them are those which emphasize the role of angular orbital momentum in the spin structure of the…
Nuclear parton distributions and structure functions are determined in an effective chiral quark theory. We also discuss an extension of our model to fragmentation functions.
There are polarized structure functions $b_{1-4}$ for the spin-1 deuteron. We calculated the leading-twist tensor structure function $b_1$ by using convolution description for the deuteron. We found large differences between our theoretical…
Recently it was proposed that the constituent quark is a topological soliton. I investigate this soliton, calculating its mass, radius, magnetic moment, color magnetic moment, and spin structure function. Within the approximations used, the…
We discuss a nonperturbative mechanism for one-spin asymmetries in inclusive hadron production. The main role in generation of this asymmetry belongs to the orbital angular momentum of quark-antiquark cloud in internal structure of…
It is shown that the momentum density of free electromagnetic field splits into two parts. One has no contribution to the net momentum due to the transversality condition. The other yields all the momentum. The angular momentum that…
A summary is given of how spin enters in collinearly factorizing processes. Next, theoretical aspects of polarization in processes beyond collinear factorization are discussed in more detail, with special focus on recent developments…
Some novel aspects of spin studies at RHIC are summarized along with the persistent problems. Among them are those which emphasize the role of angular orbital momentum in the spin structure of the constituent quarks.
We study the structure of constituent quarks by dressing bare quarks with the Goldstone bosons and its implications for quark distribution functions of hadrons $f_1(x)$, $g_1(x)$ and $h_1(x)$. In particular we discuss effects of the…
It is shown that in the special infinite momentum frame where photon has pure transverse components at $P\rightarrow\infty$ the spin-dependent deep inelastic structure function $ g_{2}(x)$ has a reasonable interpretation in terms of…
I begin with a general discussion about importance of constructing a picture of the nucleon in terms of QCD degrees of freedom, emphasizing the role of spin structure functions. I then give a short overview on the theoretical and…
I review the spin dependent structure functions which control dominant (twist-2) and sub-dominant (twist-3) phenomena in hard processes. Novel effects associated with chirally odd parton distributions and with transverse polarization are…
Hadron spin physics is now one of the most active fields of physics. Especially in the last ten years, great progress has been made both theoretically and experimentally that has considerably improved our knowledge of the spin structure of…
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…
Effect of the quark intrinsic motion on the proton spin structure functions is demonstrated. It is shown, that the covariant version of the quark-parton model taking into account the orbital motion gives the consistent picture of the proton…
We calculate the spin dependent structure functions g_{1}(x) and g_{2}(x) of the proton and neutron. Our calculation uses the meson cloud model of nucleon structure, which has previously given a good description of the HERMES data on…
We consider low-$x$ behaviour of the spin structure functions $g_1(x)$ and $h_1(x)$ in the unitarized chiral quark model which combines ideas on the constituent quark structure of hadrons with a geometrical scattering picture and unitarity.…