Related papers: Longitudinal Structure Function at Intermediate x …
The present knowledge of the structure of the photon is presented based on results obtained by measurements of photon structure functions at e+e- collider. Results are presented both for the QED structure of the photon as well as for the…
To resolve various outstanding issues associated with the twist four longitudinal structure function ${F_L^{\tau=4}(x)}$ we perform an analysis based on the BJL expansion for the forward virtual photon-hadron Compton scattering amplitude…
This is a talk given at Ringberg Workshop:"New Trends in HERA Physics", 30 May - 4 June, 1999.In this talk we discuss how deeply the region of high parton densities has been studied experimentally at HERA. We show that the measurements of…
Self-similarity based model of proton structure function at small \textit{x} was reported in the literature sometime back. The phenomenological validity of the model is in the kinematical region $ 6.2\, \times \, 10^{-7} \leq x \leq…
In this paper, the proton structure function $F_2 ^p (x,Q^2)$ at small-$x$ is investigated using an analytical solution of the Balitsky-Kovchegov (BK) equation. In the context of the color dipole description of deep inelastic scattering…
The QCD structure of the electron is defined and calculated. The leading order splitting functions are extracted, showing an important contribution from $\gamma$-$Z$ interference. Leading logarithmic QCD evolution equations are constructed…
A slight incompatibility in recent low-energy and high-energy \alpha_s measurements can be interpreted as evidence for new light colour degrees of freedom. Assuming that these are the gluinos of a supersymmetric extension of the Standard…
Recent diffractive structure function measurements by the H1 and ZEUS experiments at HERA are reviewed. Various data sets, obtained using systematically different selection and reconstruction methods, are compared. NLO DGLAP QCD fits are…
Power-suppressed corrections to parton evolution may affect the theoretical accuracy of current determinations of parton distributions. We study the role of multigluon-exchange terms in the extraction of the gluon distribution for the Large…
We perform a global fit to the structure function F_2 measured in lepton-proton experiments at small values of Bjorken-x, x\le 0.01, for all experimentally available values of Q^2, 0.045 GeV^2\le Q^2 \le 800 GeV^2. We show that the recent…
Using short distance QCD methods based on the operator product expansion, we calculate the $J/\psi$ photoproduction cross section in terms of the gluon distribution function of the nucleon. Comparing the result with data, we show that…
I use a direct method to extract the longitudinal structure function in the next-to-leading order approximation with respect to the number of active flavor from the parametrization of parton distributions. The contribution of charm and…
Calculations of deep inelastic processes (DIS) to next-to-next to leading order are discussed. Fitting $ep$ experiment in the range $2.5\leq Q^2\leq 230 GeV^2$, we find the coupling $\alpha_s(M_Z^2)=0.1163\pm0.0023$. We also get the gluon…
We obtain an approximate analytical form of the gluon distribution using the GLAP equation with a factorization ansatz,and test its validity by comparing it with that of Gluck,Reya and Vogt at low $x$ regime. We also present calculations of…
A constituent gluon model that is informed by recent lattice field theory is developed. The model is then used to compute hybrid strong decay widths, that can be useful for the GlueX collaboration at Jefferson Lab and the PANDA…
The cross section of inclusive diffractive process ep -> eXp was measured within a wide kinematic range in the H1 and ZEUS experiments at HERA. Results obtained by different experiments and methods are compatible within measurement…
In this talk I review the low x QCD experimental results from HERA and their theoretical underpinnings. In particular, I discuss the structure function $F_2$, large rapidity gap events, pomeron structure functions and $J/\psi$ production.
Results of our next-to-leading order analytic calculation for longitudinally polarized photoproduction of heavy quarks are presented. Certain differential cross sections and the corresponding asymmetries are computed for energy ranges…
Using Laplace transform techniques, we describe the determination of the longitudinal structure function $F_{L}(x,Q^2)$, at the leading-order approximation in momentum space, from the structure function $F_{2}(x,Q^2)$ and its derivative…
Muon pair production in the process e+e- -> e+e-mu+mu- is studied using the data taken at LEP1 (sqrt(s) \simeq m_Z) with the DELPHI detector during the years 1992-1995. The corresponding integrated luminosity is 138.5 pb^{-1}. The QED…