Related papers: Singularities in Twist-3 Quark Distributions
The definitions of the quark and gluon transversity generalized parton distributions (GPDs) in spin-3/2 particles are obtained in the light-cone gauge. It is found that they contain 16 independent components for each parton. Their even or…
It is anticipated that hard double parton scatterings will occur frequently in the collisions of the LHC, producing interesting signals and significant backgrounds to certain single scattering processes. For double scattering processes in…
We present the main results of our recent papers, where we derived an analytical solution of the QCD evolution equations for parton distribution functions. The valence and non-singlet quark components satisfy the Gross-Llewellyn-Smith and…
Phenomenological studies of transverse momentum dependent (TMD) parton distributions rely on the expansion in small values of the transverse separation of fields, where TMD parton distributions match onto collinear parton distribution…
In hard collisions at a hadron collider the most appropriate description of the initial state depends on what is measured in the final state. Parton distribution functions (PDFs) evolved to the hard collision scale Q are appropriate for…
This study investigates the sub-leading twist generalized transverse momentum dependent distributions (GTMDs) of a proton within the light-front quark-diquark model (LFQDM) framework. We solve the parametrization equations for the Dirac…
We present a calculation of the twist-3 T-odd chiral-even fragmentation functions $G^{\perp}$ and $\tilde{G}^{\perp}$ using a spectator model. We consider the effect gluon exchange to calculate all necessary one-loop diagrams for the…
We report on the first calculation of the structure function g_1 in polarised deep-inelastic scattering to the third order in massless perturbative QCD. The calculation follows the dispersive approach already used for the corresponding…
We discuss the link between the chiral symmetry of QCD and the numerical results of the light-front quark model, analyzing both the twist-2 and twist-3 distribution amplitudes of a pion. In particular, we exhibit that the pion twist-3…
According to recent studies, Parton Distribution Functions (PDFs) and Generalized Parton Distributions (GPDs) can be evaluated in a Constituent Quark Model (CQM) scenario, considering the constituent quarks as composite objects. In here, a…
The one loop matching kernels between parton distribution functions (PDFs) for parton $i=u,d,s,g$ and their corresponding quasi-PDFs are computed at one loop in the hybrid-ratio scheme. We found that, in addition to the conservation of the…
The spin structure of nucleon at twist 2 and 3 levels is analyzed. The contribution of quark and gluon spins to nucleon spin are Lorentz invariant, while it is not sure for orbital angular momentum. The conserved fractional moments of…
The transverse momentum dependent distributions (TMD) are an essential part of the factorization theorems in vector boson production. They are non-perturbative, double scale dependent functions that asymptotically match onto collinear…
We report the first calculation of the simplest but most fundamental transverse momentum dependent (TMD) distribution of quarks in the nucleon, i.e. the time-reversal-even unpolarized TMD quark and antiquark distribution with isoscalar…
We compute non-perturbatively the evolution of the twist-2 operators corresponding to the average momentum of non-singlet quark densities. The calculation is based on a finite-size technique, using the Schr\"odinger Functional, in quenched…
We present three new sets of next-to-leading order parton distribution functions (PDFs) determined by global fits to a wide variety of data for hard scattering processes. The analysis includes target mass and higher twist corrections needed…
We study the Wigner functions of the nucleon which provide multidimensional images of the quark distributions in phase space and combine in a single picture all the information contained in the generalized parton distributions (GPDs) and…
We discuss the single-spin asymmetry in semi-inclusive DIS, $e p^\uparrow \to e \pi X$, based on the twist-3 mechanism in the collinear factorization relevant for the pion production with the large transverse-momentum. This updates our…
The statistical approach is used to calculate the parton distribution functions (PDFs) of the nucleon. At first it is assumed that the partons are free particles and the light-front kinematic variables are employed to extract the Bjorken…
It is shown that the azimuthal dependence of the distribution of hadrons in a quark jet is a probe of the transverse spin of the quark initiating the jet. This results in a new spin-dependent fragmentation function that acts at the twist-2…