相关论文: Mass effects in the polarized virtual photon struc…

We extract polarized parton distribution functions (PPDFs), referred to as "KTA17," together with the highly correlated strong coupling $\alpha_s$ from recent and up-to-date $g_1$ and $g_2$ polarized structure functions world data at…

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…

Photoproduction of a pair of particles with large invariant mass is a natural extension of collinear QCD factorization theorems which have been much studied for deeply virtual Compton scattering and deeply virtual meson production. We…

For the magnetic field in order of the Schwinger critical value or much larger it, the effective mass of a real photon with a preset polarization is investigated in the energy region including two lower creation thresholds of electron and…

Theoretical modeling of surface emission from magnetized neutron stars (NSs) requires proper treatment of QED effects, in particular the effect of photon mode conversion due to the ``vacuum resonance'' between plasma and vacuum…

We estimate kinematical higher-twist (up to twist 4) corrections to the $\gamma^*(q_1) \gamma(q_2) \to M(p_1) \bar{M}(p_2)$ amplitudes at large $Q^2=-q_1^2$ and small $s=(q_1+q_2)^2$, where $M$ is a scalar or pseudoscalar meson. This…

The polarization operator is investigated at arbitrary photon energy in a constant and homogeneous magnetic field for the strength H less than the Schwinger critical value. The effective mass of a real photon with a preset polarization is…

The photon structure function F2-gamma(x,Q**2) has been measured using data taken by the OPAL detector at centre-of-mass energies of 91Gev, 183Gev and 189Gev, in Q**2 ranges of 1.5 to 30.0 GeV**2 (LEP1), and 7.0 to 30.0 GeV**2 (LEP2),…

The QCD higher order effects to the polarized structure function $g_2(x, Q^2 )$ are reanalyzed for massive quarks in the context of the operator product expansion. We confirm that the lowest moment of $g_2 (x, Q^2 )$ which corresponds to…

We evolve virtual photon parton densities up to the SUSY threshold and higher using coupled inhomogeneous DGLAP differential equations. Reliable input parameterizations were available from the c-quark threshold. Limited $P^2$ ( target…

The polarization operator of a photon in a constant and uniform magnetic field is studied taking into account the radiation width and shift of the Landau levels in both weak and strong fields compared with the critical field…

In this paper we present the result of a direct QCD sum rule calculation of the transition form factor \gamma\gamma* -> pi^o in the region of moderately large invariant momentum Q^2 > 1GeV^2 of the virtual photon. In contrast to pQCD, we…

For the special case of compact QED in (2+1) dimensions, we calculate the non-Gaussian vacuum wave-functional to second order in the monopole fugacity and obtain the effective photon mass. Our method presents some hope for understanding the…

We compute the structure function $g_2$ for a gluon target in perturbative QCD at order $\as$. We show that its first moment vanishes, as predicted by the Burkhardt-Cottingham sum rule.

The memory effect of test particles interacting with pp-wave Gaussian pulses is investigated for polarization modes beyond the standard quadrupolar $+$ and $\times$ states. Massive geodesic equations are solved numerically for several…

We derive the Wigner functions of polarized photons in the Coulomb gauge with the $\hbar$ expansion applied to quantum field theory, and identify side-jump effects for massless photons. We also discuss the photonic chiral vortical effect…

We calculate the polarized massive two--loop pure singlet Wilson coefficient contributing to the structure functions $g_1(x,Q^2)$ analytically in the whole kinematic region. The Wilson coefficient contains Kummer--elliptic integrals. We…

The impact of the recent very precise CLAS and COMPASS g_1/F_1 data on polarized parton densities and higher twist effects is discussed. We demonstrate that the low Q^2 CLAS data improve essentially our knowledge of higher twist corrections…

We consider a hybrid of nonlinear sigma models in which two complex projective spaces are coupled with each other under a duality. We study the large N effective action in 1+1 dimensions. We find that some of the dynamically generated gauge…

We examine the implications of several parameterizations of so-called target mass corrections (TMCs) for the physics of parity-violating deeply inelastic scattering (DIS), especially at high values of the momentum fraction x. We consider…