Related papers: Separation of Quark Flavors using DVCS Data
The charge, magnetic and quadrupole form factors of vector mesons and the charge form factor of pseudo-scalar mesons are calculated in quenched lattice QCD. The charge radii and magnetic moments are derived. The quark sector contributions…
Virtual Compton Scattering (VCS) at low transferred momenta to the proton ($t$) and sufficiently high c.m. energies ($s$) may be used to a) study $Q^2$--dependence of leading $t$--channel exchanges and b) look for onset of scaling behavior…
Recent calculations of charge symmetry violation(CSV) in the valence quark distributions of the nucleon have revealed that the dominant symmetry breaking contribution comes from the mass associated with the spectator quark system.Assuming…
Within the framework of the Color Glass Condensate model, we evaluate quark and gluon Generalized Parton Distributions (GPDs) and the cross section of Deeply Virtual Compton Scattering (DVCS) in the small-$x_{B}$ region. We demonstrate that…
Information about double parton distributions (DPDs) can be obtained by calculating four-point functions on the lattice. We continue our study on the first DPD Mellin moment of the unpolarized proton by considering interference effects…
We present an application of the unitarity-based dispersion matrix (DM) approach to the extraction of the CKM matrix element $|V_{cb}|$ from the experimental data on the exclusive semileptonic $B_{(s)} \to D_{(s)}^{(*)} \ell \nu_\ell$…
The framework of the expansion by subgraphs is used to compute asymptotic expansions for the vector and the tensor currents in the limit of large quark masses. We use the results to obtain an estimate for the influence of heavy quarks on…
We calculate the nucleon resonance contributions to nucleon Compton scattering, including all states with J^P = 1/2^{+-} and J^P = 3/2^{+-} where experimental data for their electromagnetic transition form factors exist. To this end, we…
We discuss methods for the calculation of disconnected diagrams and their application to various form factors of the nucleon. In particular, we present preliminary results for the strange contribution to the scalar and axial form factors,…
We compute the cross section for leptoproduction of the real photon off the nucleon, which is sensitive to the deeply virtual Compton scattering amplitude with power accuracy. Our considerations go beyond the leading twist and involve the…
We compute the amplitude of deeply virtual Compton scattering (DVCS) using the calculus of QCD string operators in coordinate representation. To restore the electromagnetic gauge invariance (transversality) of the twist-2 amplitude we…
Beginning with precise data on the ratio of structure functions in deep inelastic scattering (DIS) from $^3$He and $^3$H, collected on the domain $0.19 \leq x_B \leq 0.83$, where $x_B$ is the Bjorken scaling variable, we employ a robust…
The u- and d-quark contributions to the elastic nucleon electromagnetic form factors have been determined using experimental data on GEn, GMn, GpE, and GpM. Such a flavor separation of the form factors became possible up to 3.4 GeV2 with…
I review the various methods for taking account of finite quark masses in DIS and related processes. I pay particular attention to the so-called variable flavour number schemes (VFNS) which are designed to extrapolate smoothly from the…
We develop a framework to establish benchmarks for machine learning and deep neural networks analyses of exclusive scattering cross sections (FemtoNet). Within this framework we present an extraction of Compton form factors for deeply…
We investigate the mechanics of the proton by examining the flavor-decomposed proton cosmological constants and generalized vector form factors. The interplay of up, down, and strange quarks within the proton is explored, shedding light on…
We obtain the gravitational form factors (GFFs) and investigate their applications for the description of the mechanical properties, i.e., the distributions of pressures, shear forces inside proton, and the mechanical radius, in a…
New results on the Deeply Virtual Compton Scattering process $\gamma^* p \to \gamma p$ (DVCS) from H1 experiment at the $e p$ collider HERA are presented, using data collected during the year 2004 and corresponding to an integrated…
We address quarkonium formation at moderate to large transverse momenta, where the single-parton collinear fragmentation prevails over the short-distance emission, directly from the hard sub-scattering, of the constituent heavy-quark pair.…
We analyze the hard scattering amplitude of the gravitational form factors (GFFs) of hadrons at one-loop, in relation to their conformal field theory (CFT) description, within the framework of QCD factorization for hard exclusive processes…