Related papers: Light-Cone Wavefunction Representation of Deeply V…
In this work, real photon production scattering kernels from jet-medium interactions in the QCD medium are perturbatively calculated using the higher-twist (HT) formalism. Focus is given towards real photon production from a highly virtual…
We investigate the Compton scattering vertex of charged scalars and photons in scalar quantum electrodynamics (SQED). We carry out its non perturbative construction consistent with Ward-Fradkin-Green-Takahashi identity (WFGTI) which relates…
The distribution of the parton content of nuclei, as encoded via the generalized parton distributions (GPDs), can be accessed via the deeply virtual Compton scattering (DVCS) process contributing to the cross section for leptoproduction of…
We calculate the one-loop corrections to a general off-forward deeply-virtual Compton process at leading twist for both parton helicity-dependent and independent cases. We show that the infrared divergences can be factorized entirely into…
We present the results of calculations analyzing nucleon Compton scattering to lowest order using perturbative QCD (pQCD) methods. Two scenarios are considered: (1) the incoming photon is real; and (2) the incoming photon is virtual. The…
The Weisberger relation, an exact statement of the parton model, elegantly relates a high-energy physics observable, the 1/x moment of parton distribution functions, to a nonperturbative low-energy observable: the dependence of the nucleon…
After about 10 years of growing interest for Generalized Parton Distributions come the first results from dedicated experiments, using the golden Deeply Virtual Compton Scattering process. After a short introduction, we will explain the…
Exclusive photoproduction of dileptons, gamma N->e+e-N, is and will be measured in ultraperipheral collisions at hadron colliders, such as the Tevatron, RHIC and the LHC . We demonstrate that the timelike deeply virtual Compton scattering…
At moderate and large momentum transfer, high energy vector meson photoproduction and Compton scattering can be consistently explained by mechanisms based on interactions and exchanges of constituent quarks and gluons. This opens an…
We report a Virtual Compton Scattering study of the proton at low CM energies. We have determined the structure functions $P_{LL}-P_{TT}/\epsilon$ and $P_{LT}$, and the electric and magnetic Generalized Polarizabilities (GPs) $\alpha_E(Q2)$…
Light-cone Fock-state wavefunctions encode the properties of a hadron in terms of its fundamental quark and gluon degrees of freedom. A recent experiment at Fermilab, E791, demonstrates that the color coherence and shape of light-cone…
I outline a perturbative QCD approach to the analysis of the deeply virtual Compton scattering process $\gamma^* p \to \gamma p'$ in the limit of vanishing momentum transfer $t= (p' - p)^2$. The DVCS amplitude in this limit exhibits a…
We evaluate within a microscopic calculation the contributions of both coherent and incoherent deeply virtual Compton scattering from a spin-0 nucleus. The coherent contribution is obtained when the target nucleus recoils as a whole,…
The local coupling of two photons to the fundamental quark currents of a hadron gives an energy-independent contribution to the Compton amplitude proportional to the charge squared of the struck quark, a contribution which has no analog in…
We report on the first measurement of exclusive single-photon muoproduction on the proton by COMPASS using 160 GeV/$c$ polarized $\mu^+$ and $\mu^-$ beams of the CERN SPS impinging on a liquid hydrogen target. We determine the dependence of…
Interactions of virtual photons are analyzed in terms of photon structure. It is argued that the concept of parton distribution functions is phenomenologically very useful even for highly virtual photons involved in hard collisions. This…
We propose detailed tests of the handbag approximation in exclusive deeply virtual Compton scattering. Those tests make no use of any prejudice about parton correlations in the proton which are basically unknown objects and beyond the scope…
We study the timelike virtual Compton scattering process with a linearly polarized photon beam, in the generalized Bjorken scaling region and in the medium energy range which will be studied intensely at JLab12 experiments. We define new…
Applications of perturbative QCD to deeply virtual Compton scattering and hard exclusive electroproduction processes require a generalization of usual parton distributions for the case when long-distance information is accumulated in…
Applications of perturbative QCD to deeply virtual Compton scattering and hard exclusive electroproduction processes require a generalization of the usual parton distributions for the case when long-distance information is accumulated in…