Related papers: Distributed Spin in a String Picture of Hadrons
We investigate classical Heisenberg spins on a conical surface. The energy and configuration of non-trivial spin distributions are obtained using a non-conventional method based on Einstein theory of gravity in lower dimensions.
Exploiting the strict analogy between the motion of strings and extended-like spinning particles, we propose an original kinematical formulation of the spin of bosonic strings and give, for the first time, an analytical derivation of an…
This article is an introduction to parton distribution functions and their generalizations which describe the quark and gluon structure of hadrons, and can be measured in various high-energy scattering processes. We provide the theoretical…
The commutator of string fields is considered in the context of light cone string field theory. It is shown that the commutator is in general non--vanishing outside the string light cone. This could have profound implications for our…
Generalized parton distributions provide a unified parameterization of hadron structure and allow one to combine information from many different observables. Lattice QCD calculations already provide important input to determine these…
The strong force which binds hadrons is described by the theory of quantum chromodynamics (QCD). Determining the character and manifestations of QCD is one of the most important and challenging outstanding issues necessary for a…
The spin structure of the nucleon is analyzed in the framework of a Lorentz-invariant formulation of baryon chiral perturbation theory. The structure functions of doubly virtual Compton scattering are calculated to one-loop accuracy (fourth…
We formulate a new geometrical string on the euclidean lattice. It is possible to find such spin systems with local interaction which reproduce the same surface dynamics.In the three-dimensional case this spin system is a usual Ising…
The present understanding of the spin structure of the nucleon is briefly reviewed. The main focus is on parton helicity distributions, orbital angular momentum of partons as defined through generalized parton distributions, as well as…
We study meson spectrum obtained from massive open string modes in a holographic dual of QCD constructed on the basis of a D4/D8-brane configuration in type IIA string theory. The spectrum includes mesons with spin higher than one. Taking…
We continue the study of non-Abelian vortex string in 4D $\mathcal{N}=2$ supersymmetric QCD as critical superstring, and extend this analysis to $U(N)$ gauge theory with arbitrary even $N$ and $N_f=2N$ number of quarks. We introduce a…
We address the issue of hadron deformation within the framework of lattice QCD. For hadrons with spin greater than 1/2 the deformation can be determined by evaluating the charge and matter distributions. Deviation of the nucleon shape from…
After a brief recapitulation of the general interest of parton densities, we discuss multiple hard interactions and multiparton distributions. We report on recent theoretical progress in their QCD description, on outstanding conceptual…
The recent progress in the investigations on the quark structure of the $\Lambda$ and $\Sigma$ baryons are reviewed. It is shown that the quark structure of $\Lambda$ and $\Sigma$ hyperons can provide a new domain to test various theories…
Spin effects in exclusive and inclusive reactions provide an essential new dimension for testing QCD and unraveling hadron structure. Remarkable new experiments from SLAC, HERMES (DESY), and the Jefferson Laboratory present many challenges…
The relation between parton and hadron multiplicity distributions is discussed. To obtain parton multiplicity distribution we propose decomposition of the multiplicity distributions of final state hadrons. Such procedure offers hope for…
An overview is given of the way in which the unification program of particle physics has evolved into the proposal of superstring theory as a prime candidate for unifying quantum gravity with the other forces and particles of nature. A key…
We review some recent results on phenomenological approaches to strong interactions inspired in gauge/string duality. In particular, we discuss how such models lead to very good estimates for hadronic masses.
We review the current status and future perspectives of theory and experiments of transverse spin phenomena in high-energy scattering processes off nucleon targets and related issues in nucleon structure and QCD. Systematic exploration of…
In this study, we assume the hadrons as an ensemble of quark-gluon Fock states and apply statistical effects to explain the spin distribution of quarks for lambda hyperon. We extend the principle of detailed balance given by Zhang et al.…