相关论文: Polarized Gluon Distribution Delta g(x) in the Pro…
The number of events suitable for a determination of the gluon distribution function g(x,Q^2) in a proton at the LHC for various intervals of x and Q^2 are estimated. The contributions of main background sources to ``direct photon+jet''…
We propose to access the gluon polarization $\Delta G$ by measuring the cross section spin-asymmetry in semi-inclusive polarized lepton -- nucleon scattering. The photon-gluon fusion sub-process will be tagged by detecting high-$p_T$…
Based on a solution of DGLAP evolution equations at small values of Bjorken variable x, a simple analytic approximation for so-called linearly polarized gluon density \tilde{h}_1^{\perp g}(x,k_t^2, Q^2) is obtained at LO of perturbation…
We present the polarized parton distribution functions from a QCD analysis of the worldwide polarized deep inelastic scattering data, based on the dynamical parton distribution model. All the sea quarks and gluons are dynamically generated…
The sensititivity of various future polarization experiments to the first moment Delta g of the polarized gluon density is elucidated in detail. It is shown to what extent the first moment can be extracted from the future data as compared…
The quasi-probabilistic Wigner distributions are the quantum mechanical analog of the classical phase-space distributions. We investigate quark Wigner distributions for a quark state dressed with a gluon, which can be thought of as a simple…
The gluon polarization $\Delta{G}/G$ is the key to a further clarification of the spin structure of the nucleon. The COMPASS collaboration at CERN has set out to undertake the direct determination of this quantity. It accesses the gluon…
Linearly polarized gluons inside an unpolarized proton contribute to the transverse momentum distributions of (pseudo)scalar particles produced in hadronic collisions, such as Higgs bosons and quarkonia with even charge conjugation…
We have utilized the concept of valon model to calculate the spin structure functions of proton, neutron and deuteron. The valon structure itself is universal and arises from the perturbative dressing of the valence quark in QCD. Our…
The contribution to proton helicity from the spins of quarks and gluons at small Bjorken $x$ can be conveniently studied through the small-$x$ helicity evolution. Recently, it has been employed in a global analysis that includes polarized…
We compute the full x - dependence of the proton and neutron spin structure functions in the MIT bag model, including the effect of gluon exchange and the meson cloud. Impressive agreement is found for x larger than 0.1, where polarised…
A new preliminary result of a gluon polarisation \Delta G/G obtained selecting high transverse momentum hadron pairs in DIS events with Q^2>1 (GeV/c)^2 is presented. Data has been collected by COMPASS at CERN during the 2002-2004 years. In…
The gluon distribution is dominated by the hard pomeron at small $x$ and all $Q^2$, with no soft-pomeron contribution. This describes well not only the DGLAP evolution of the hard-pomeron part of $F_2(x,Q^2)$, but also charm photoproduction…
A small-$x$ helicity evolution has been derived in 2016-18 and received an important modification in 2022. This article discusses its general framework and summarizes the recent theoretical developments, including the asymptotic behaviors…
We show that the production of a Higgs boson in association with a jet in proton-proton collisions is sensitive to the linear polarization of gluons inside unpolarized protons. We present the analytical expressions, at leading order in…
Generalized parton distributions with helicity flip are studied in the quark sector, within a simple version of the MIT bag model, assuming an SU(6) wave function for the proton target. In the framework under scrutiny it turns out that only…
We present a new next-to-leading order QCD analysis of the world data on inclusive polarized deep inelastic lepton-nucleon scattering adding to the old set of data the final SMC results, the HERMES proton and very recent SLAC/E155 deuteron…
The proton spin structure is not understood yet and there has remained large uncertainty on Delta g, the gluon spin contribution to the proton. Double helicity asymmetry (A_LL) of pi0 production in polarized pp collisions is used to…
We investigate the possibility to identify photon-gluon fusion (PGF) events in polarised deep inelastic ep scattering, assuming the kinematics of the HERA collider, by a pair of charged high p_t particles. In a Monte Carlo study we find…
In this talk results from a new QCD analysis in leading (LO) and next--to--leading (NLO) order are presented. New parametrizations of the polarized quark and gluon densities are derived together with parametrizations of their fully…