Related papers: Large $p_{\perp}$ Exclusive Processes:RECENT Devel…
We analyze effects due to transverse degrees of freedom in QCD calculations of the fundamental hard exclusive amplitude of $\gamma^*\gamma \to \pi^0$ transition. A detailed discussion is given of the relation between the modified…
In this talk various spin effects in hard exclusive electroproduction of mesons are briefly reviewed and the data discussed in the light of recent theoretical calculations within the frame work of the handbag approach. For electroproduction…
We calculate the photon production cross section arising from the hard scattering of partons in nucleon-nucleon collisions by taking into account the intrinsic parton transverse momentum distribution and the next-to-leading-order…
A number of hard exclusive scattering processes can be described in terms of generalized parton distributions (GPDs) and perturbative hard-scattering kernels. Both the physical amplitude and the hard-scattering kernels fulfill dispersion…
The relevance of intrinsic (or primordial) transverse momentum of partons in the inclusive production of particles at high energy and moderately large p_T has been known for a long time, beginning with Drell-Yan and diphoton processes, and…
We report on a calculation of the `mixed' strong and (purely) weak corrections through the order $\alpha_{\mathrm{S}}^2\alpha_{\mathrm{W}}$ to parton-parton processes in all possible channels at hadron colliders entering the single jet…
An effective description of hadronic matter in terms of "effective free particles" is presented. Repulsive interactions among the hadrons have been modelled by Excluded volume correction by considering the hadrons as liquid drops, whose…
The electromagnetic form factors of hadrons at large momentum transfer have been the subject of intense theoretical and experimental scrutiny over the past two decades, yet there is still not a universally-accepted framework for their…
Recent progress in the perturbative analysis of hadronic jets, especially in the context of hadron colliders, is discussed. The characteristic feature of this work is the emergence of a level of precision in the study of the strong…
We compute pseudorapidity and transverse momentum distributions for charm and bottom production at HERA. We examine the effect of next-to-leading order QCD corrections, the effect of possible intrinsic transverse momenta of the incoming…
We discuss the process $p+p\to h_1+h_2+X$, where the identified hadrons $h_1$ and $h_2$ have large transverse momenta and are produced in high-energy proton-proton collisions with a large rapidity gap between them. In this case the…
To match the precision of present and future measurements of Z-boson production at hadron colliders, electroweak radiative corrections must be included in the theory predictions. In this paper we consider their effect on the transverse…
Virtual photons have proven to be very efficient probes of the hadronic structure, mostly through deep inelastic scattering and related processes. The advent of high luminosity lepton beams has allowed to enlarge the studied processes to…
The relativistic Faddeev equation for three-nucleon scattering is formulated in momentum space and directly solved in terms of momentum vectors without employing a partial wave decomposition. Relativistic invariance is achieved by…
Using the renormalon technique, we estimate higher-twist contributions in deeply virtual Compton scattering and in hard exclusive $\pi^0$ leptoproduction.
We study pion production in proton-proton collisions within a pQCD-improved parton model in next-to-leading order augmented by intrinsic transverse momentum ($k_\perp$) of the partons. We find the introduction of $k_\perp$ necessary to…
We analyze the electromagnetic pion and kaon form factor by including radiative and higher-twist effects within the framework of resummed pQCD in the space-like region. We focus on the transition from the perturbative to non-perturbative…
We discuss a constraint of conformal symmetry in the analysis of the pion form factor. The usual power-law behavior of the form factor obtained in the perturbative QCD analysis can also be attained by taking negligible quark masses in the…
We considered the power corrections to the amplitude describing hard exclusive pion pair production in gamma gamma collisions at large energy and momentum transfer. In order to derive a factorization formula for the subleading power…
It is shown that the dependence of ratio $f_s/f_d$ could be understood within the fragmentation approach. However, the validity of fragmentation model is questionable at low $p_T$, and contributions of nonfragmentation mechanisms are…