相关论文: NLO photon parton parametrization using ee and ep …
We employ the exact factorization of a multi-component wavefunction to analyze the dynamics of interacting photons, electrons and nuclei. We consider physical situations emerging in the regime of strong coupling between light excitations…
A recent global analysis of direct photon production at hadron collider and fixed target experiments has noted a disturbing trend of disagreement between next-to-leading-order (NLO) calculations and data. The conjecture has been made that…
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…
NLO QCD fits using the DGLAP formalism have been made to the high precision ZEUS $e^+p$ reduced cross-section data and to fixed target structure function data, in order to detrmine parton distribution functions and the value of…
The electromagnetic nucleon form-factors data are studied with artificial feed forward neural networks. As a result the unbiased model-independent form-factor parametrizations are evaluated together with uncertainties. The Bayesian approach…
A numerical program to calculate the photoproduction of prompt photons is presented. The code includes full next-to-leading order corrections to all subprocesses. The results are compared to recent ZEUS data.
We derive an expression for the electron to nucleon mass ratio from a reinterpreted lattice gauge theory Hamiltonian to describe interior baryon dynamics. We use the classical electron radius as our fundamental length scale. Based on…
We report on several methodologically different NNLO determinations of the strong coupling constant from event shapes and related observables in e+e- annihilation. The event shape distributions are analyzed within a combined framework of…
Using the NMC and E665 nuclear structure function ratios $F_2^A/F_2^D$ and $F_2^A/F_2^{C}$ from deep inelastic lepton-nucleus collisions, and the E772 Drell--Yan dilepton cross sections from proton-nucleus collisions, and incorporating…
Nonlinear optical properties (NLOPs) play a major role in photonics, electro-optics and optoelectronics, and other fields of modern optics. The design of new NLO molecules and materials has benefited from the development of computational…
We extract the ratio of the down (d) and up (u) parton distribution functions (PDF's) from the ratio of NMC deuteron and proton structure function F_2(d)/F_2(p), using corrections for nuclear binding effects in the deuteron, which are…
We present the first calculation of inclusive jet photoproduction with next-to-next-to-leading order (NNLO) contributions, obtained from a unified threshold resummation formalism. The leading coefficients for direct photoproduction are…
The process $e^+e^- \rightarrow N\bar N$ is studied nearby a threshold with account for polarizations of all initial and final particles. The nucleon polarization $\bm \zeta^N$ reveals a strong energy dependence due to that of the nucleon…
We propose a modification of the equivalent photon approximation (EPA) for processes which involve the parton content of the photon, to take into account the suppression of the photonic parton fluxes due to the virtuality of the photon. We…
Collider data can play an important role in determining the parton distribution functions of the nucleon. I outline a formalism which makes it possible to use next-to-leading order calculations in such an extraction, while minimizing the…
In this work, we present a next-to-leading-order (NLO) study of $J/\psi + \gamma$ production via photon-photon fusion in proton-proton ultraperipheral collisions (UPCs) at $\sqrt{s_{NN}} = 14$ TeV. The calculation is performed within the…
We report on the calculation of NNLO corrections to the 3-jet cross section and related event shape distributions in electron-positron annihilation. The corrections are sizable for all variables, however the magnitude of the corrections is…
We recall our recent description of quark parton densities of the proton at $Q^2=4 GeV^2$ in terms of Fermi-Dirac distributions parametrized with very few free parameters. We have also proposed some simple assumptions to relate unpolarized…
Recent progresses of the proton structure measurements and determination of parton distribution functions by $ep$ collisions at HERA are introduced.
We shown the general approach for Q2 evolution of parton densities and fragmentation functions at low x based on the diagonalization. The diagonalization leads to the two components in the Q2 evolution, each of which contains a…