Related papers: Spin-Dependent Structure Functions of the Photon

Double-polarization asymmetries for inclusive $ep$ scattering were measured at Jefferson Lab using 2.6 and 4.3 GeV longitudinally polarized electrons incident on a longitudinally polarized NH$_3$ target in the CLAS detector. The polarized…

The spin-dependent structure functions $g_1(x)$, $g_2(x)$, ${g}_2^{WW}(x)$ and ${\bar g}_2(x)$ and their moments are studied in the CM bag model. The results show that (i) $\int_0^1g_2(x)dx=0$, i.e. the Burkhardt-Cottingham sum rule holds,…

The hadronic structure of the photon F2gamma is measured as a function of Bjorken x and of the photon virtuality Q2 using deep-inelastic scattering data taken by the OPAL detector at LEP at e+e- centre-of-mass energies from 183 to 209 GeV.…

We propose the new approach for taking into account the Q2 dependence of measured asymmetry A_1. This approach is based on the similarity of the Q2 behaviour and the shape of the spin-dependent structure function g_1(x,Q^2) and spin…

Graphene quantum dots (GQDs) are nanoscale structures of graphene with quantum properties and edge effects that give photoluminescence properties. The effect of quantum confinement and differences in the nature of GQD structure makes its…

The potential of polarized, high-luminosity, moderate-energy e+e- colliders for performing unique measurements in fundamental QCD is described, with particular reference to the proposed Super-B facility. An extensive programme of 2-photon…

When a photon with well-defined polarization and momentum passes through a focusing device, these properties are no longer well defined. Their loss is captured by describing polarization by a 3x3 effective density matrix. Here we show that…

We discuss perturbative evolution of the polarized structure function g_1 in the (x,Q^2) plane, with special regard to the small-x region. We determine g_1 in terms of polarized quark and gluon distributions using coefficient functions to…

We use the covariant current formalism to derive the general form of the 2-photon correlation function for fully chaotic sources. Motivated by the recent discussion in the literature we concentrate on the effects from the photon spin on the…

In this paper, we investigate the effects of the quantity $\sigma_{TS}$ on the spin-structure functions of nucleons in the resonance region. The Schwinger sum rule for the spin structure function $g_2(x,Q^2)$ at the real photon limit is…

The strong interaction is not well understood at low energy, or for interactions with low momentum transfer $Q^2$, but one of the clearest insights we have comes from Chiral Perturbation Theory ($\chi$PT). This effective treatment gives…

We present a Next-to-Leading order perturbative QCD analysis of world data on the spin dependent structure functions $g_1^p, g_1^n$, and $g_1^d$, including the new experimental information on the $Q^2$ dependence of $g_1^n$. Careful…

We analyse the proton and deutron data on spin dependent asymmetry $A_1(x,Q^2)$ supposing the DIS structure functions $g_1(x,Q^2)$ and $F_3(x,Q^2)$ have the similar $Q^2$-dependence.

We prove that regulating infrared divergencies generates power (~1/(Q^2)^k) corrections to the spin structure function g_1 at small x and large Q^2. At the same time it leads to the corrections ~(Q^2)^k at small Q^2. We present the explicit…

Spin polarizabilities provide information on the internal structure of hadrons in the presence of weak external electromagnetic fields, and are actively studied by Compton scattering experiments. They provide finer detail than the regular…

As the size of an optical vortex knot, imprinted in a coherent light beam, is decreased, nonparaxial effects alter the structure of the knotted optical singularity. For knot structures approaching the scale of wavelength, longitudinal…

The distribution of the spin of the nucleon among its constituents can be parametrized in the form of polarized parton distribution functions for quarks and gluons. Using all available data on the polarized structure function $g_1(x,Q^2)$,…

We investigate the heavy quark mass effects in the virtual photon structure functions $F_{2}^{\gamma}(x, Q^2, P^2)$ and $F_{L}^{\gamma}(x, Q^2, P^2)$ in the framework of the mass-independent renormalization group equation (RGE). We study a…

The recent high precision SMC data on polarized $\mu p$ scatterings have again confirmed that very little of the proton spin is carried by quarks. To unravel the mystery of the proton spin structure, it is quite important to know the…

The pion structure function is investigated in a simple model, where pion and constituent quark fields are coupled through the simplest pseudoscalar coupling. The imaginary part of the forward gamma* pi-> gamma* pi scattering amplitude is…