Related papers: Asymmetric Quarks in the Proton
Over the years, comprehensive experiments have shown a fact that the nucleons, such as the proton and neutron, are formed by not only the "valence" up and down quarks which were thought to comprise the nucleons in a simple constituent…
We study the production of $W^{\pm}$ and $Z$ gauge bosons in proton-proton and proton-neutron collisions up to a center-of-mass energy $\sqrt s=0.5\ TeV$, in connection with the realistic possibility of having proton-deuteron collisions at…
Parton distributions in impact parameter space, which are obtained by Fourier transforming GPDs, exhibit a significant deviation from axial symmetry when the target and/or quark is transversely polarized. In combination with the final state…
Microscopical approach to a deuteron breakup at high and intermediate energies is proposed. We show that the quark exchange effects, resulting from the full asymmetry of the $6q$-deuteron wave function with respect to the pair permutations…
There are strong theoretical indications that the minority valence quark distributions in the nucleon may break charge symmetry by as much as 3-5%. We show that a comparison of $e^{\pm} D$ deep inelastic scattering through the charged…
Polarized parton distribution functions are determined by using world data from the longitudinally polarized deep inelastic scattering experiments. A new parametrization of the parton distribution functions is adopted by taking into account…
We calculate the probability distributions of quarks in the ground state of the proton, and how they are affected in the presence of a constant background magnetic field. We focus on wave functions in the Landau and Coulomb gauges. We…
We perform a comprehensive analysis of the strange-antistrange parton distribution function (PDF) asymmetry in the proton in the framework of chiral effective theory, including the full set of lowest order kaon loop diagrams with off-shell…
A new handed interaction between quarks could be at the origin of some small parity violating effects in the inclusive production of one-jet in polarized $pp$ collisions. This interaction could originate from compositeness or from the…
The quark spin densities related to generalized parton distributions in impact-parameter space and to transverse-momentum dependent parton distributions are reviewed within a light-cone quark model, with focus on the role of the different…
While the form factors and parton distributions provide separately the shape of the proton in coordinate and momentum spaces, a more powerful imaging of the proton structure can be obtained through phase-space distributions. Here we…
We present the first simultaneous global QCD analysis of spin-dependent parton distribution functions alongside their spin-averaged counterparts and pion, kaon, and unidentified hadron fragmentation functions. This analysis includes all…
A brief review of the isospin symmetry breaking in hadrons and nuclei is given with emphasis on the $u-d$ quark mass difference. The off-shell $\rho^0-\omega$ mixing is studied as a typical example of the symmetry breaking, and its…
Hadron structure is considered in the frame of Strongly Correlated Quark Model (SCQM). It is shown that quark correlations result in fluctuations of hadronic matter distributions and single diffractive dissociation processes in hadronic…
The flavor-dependent valence, sea quark and antiquark spin distributions can be determined separately from theoretical assumptions and experimental data. We have determined the valence distributions using the Bjorken sum rule and have…
The difference between the strange and antistrange quark distributions, $\delta s(x)=s(x)-\sbar(x)$, and the combination of light quark sea and strange quark sea, $\Delta (x)=\dbar(x)+\ubar(x)-s(x)-\sbar(x)$, are originated from…
We provide a first quantitative indication that the wave function of the proton contains unequal distributions of charm quarks and antiquarks, i.e. a nonvanishing intrinsic valence charm distribution. A significant nonvanishing valence…
A comprehensive collection of results on longitudinal double-spin asymmetries is presented for charged pions and kaons produced in semi-inclusive deep-inelastic scattering of electrons and positrons on the proton and deuteron, based on the…
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…
Secondary charged hadrons multiplicity distributions in proton-proton and proton-antiproton collisions differ on principle. There are three types of inelastic processes in proton-antiproton scattering. The first type is production of…