Related papers: The Virtual Photon Structure Functions and AdS/QCD…
In this article aspects of photon-photon physics related to the structure of real and virtual photons are reviewed. A re-calculation of the virtual photon-photon box is performed and some discrepancies in the literature are clarified. A…
We discuss the perturbatively calculable virtual photon structure functions. First we present the framework for analyzing the structure functions of the virtual photon and derive a first moment of $g_1^\gamma$ of the virtual photon. We then…
We calculate the impact factor coupling a virtual photon to a gluon via a massive quark-antiquark pair at LL order, but with the imposition of the correct gluon kinematics. Exact analytical results are presented in triple Mellin space with…
The structure functions F_2 and F_1 of real photon at low virtualities are calculated in the framework of chiral perturbation theory (ChPT) in the zero and first order of ChPT. It is assumed that the virtuality of hard projectile photon Q^2…
We study the three positivity constraints among the eight virtual photon structure functions, derived from the Cauchy-Schwarz inequality and which are hence model-independent. The photon structure functions obtained from the simple parton…
The analysis on nucleon structure functions at small Bjorken $x$ in the framework of holographic QCD is presented. In the model setup, the complicated nonperturbative interaction between the virtual photon and the target nucleon is…
The status of measurements and interpretation of the proton structure function F2 is summarized. The measurements are subjected to DGLAP fits, from which the gluon density is extracted and a comparison to measurements of F2c is performed.…
Deep inelastic structure functions can be calculated from supergravity when the Bjorken parameter $x$ satisfies $ x > 1/\sqrt{gN} $. We consider a gauge theory with very large 't Hooft coupling $gN$ in order to investigate the region $x <<…
Development of concepts related to the photon and its high energy hadronic interaction is briefly reviewed. A photon considered as an ideal probe of hadron structure, paradoxically is also considered as an ideal target to test the…
We investigate the virtual photon structure function in the supersymmetric QCD (SQCD), where we have squarks and gluinos in addition to the quarks and gluons. Taking into account the heavy particle mass effects to the leading order in QCD…
Measurements sensitive to the structure of both real and virtual photons are presented and compared to theoretical models with various photon parton distribution functions (PDFs). Measurements for real photons show a tendency for the…
A proof of Bloom-Gilman duality which relates an integral over the low-mass resonances in deep inelastic structure functions to an integral over the scaling region near x = 1 is given. It is based on general analytic properties of the…
The virtual photon structure function $g_1^{\gamma}(x,Q^2,P^2)$, which can be obtained in polarized $e^{+}e^{-}$ colliding-beam experiments, is investigated for $\Lambda^2 \ll P^2 \ll Q^2$, where $-Q^2$ ($-P^2$) is the mass squared of the…
We investigate the photon structure functions at small Bjorken variable $x$ in the framework of the holographic QCD, assuming dominance of the Pomeron exchange. The quasi-real photon structure functions are expressed as convolution of the…
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 flux of papers from electron positron colliders containing data on the photon structure function ended naturally around 2005. It is thus timely to review the theoretical basis and confront the predictions with a summary of the…
Working within the AdS/CFT correspondence we calculate the three-point function of two giant gravitons and one pointlike graviton using methods of semiclassical string theory and considering both the case where the giant gravitons wrap an…
We study the dipole picture of high-energy virtual-photon-proton scattering. It is shown that different choices for the energy variable in the dipole cross section used in the literature are not related to each other by simple arguments…
Symmetric and antisymmetric structure functions from electromagnetic deep inelastic scattering of charged leptons off spin-1/2 hadrons are investigated in the framework of a top-down holographic dual description. We consider the BPST…
Photon structure functions in supersymmetric QCD are investigated in terms of the parton model where squark contributions are evaluated. We calculate the eight virtual photon structure functions by taking the discontinuity of the squark…