相关论文: Does the hard pomeron obey Regge factorisation?
Recent improvements of the hard scattering picture for the large $p_{\perp}$ behaviour of electromagnetic form factors, namely the inclusion of both Sudakov corrections and intrinsic transverse momentum dependence of the hadronic wave…
The use of the differential gluon structure function of the proton ${\cal F}(x,Q^{2})$ introduced by Fadin, Kuraev and Lipatov in 1975 is called upon in many applications of small-x QCD. We report here the first determination of ${\cal…
Two key issues in the application of perturbative QCD and Regge predictions to high energy processes are whether the hard and soft pomerons should be considered as two separate distinct exchanges and whether the Regge intercepts are Q^2…
We extend the MRS(A) set of parton distributions, which provides an up-to-date description of the structure of the proton probed by hard interactions, into the region of $Q^2$ below $5\ {\rm GeV}^2$. After physically-motivated…
We compute the proton structure function F_2^p at small x and large Q^2 at next-to-leading order in alpha_s(Q^2), including summations of all leading and subleading logarithms of Q^2 and 1/x in a way consistent with momentum conservation.…
While the main features of elastic, diffractive and total cross sections are described well by Regge theory, the measured rise of the proton-(anti)proton single diffraction dissociation cross section with energy is considerably smaller than…
It has long been believed that the Pomeron, which has been successful in phenomenological fits to high energy scattering data, is associated with gluonic exchange. By determining the Regge-nucleon vertex in terms of previously determined…
Heavy quark production in $\gamma\gamma$ collisions is reanalyzed. It is argued that evaluating the cross section $\sigma(\gamma\gamma\to Q\overline{Q})$ in a well-defined renormalization scheme requires the inclusion of direct photon…
The parametrisation of the photon structure function in the low Q^2 region is formulated. It includes the VMD contribution and the QCD improved parton model component suitably extrapolated to the low Q^2 region. The parametrisation…
We analyze the proton electromagnetic form factor ratio $R(Q^{2})=QF_2(Q^{2})/F_1(Q^{2})$ as a function of momentum transfer $Q^{2}$ within perturbative QCD. We find that the prediction for $R(Q^{2})$ at large momentum transfer $Q$ depends…
In this paper we present a combined analysis of the H1 data on leading baryon and diffractive structure functions from DIS, which are handled as two components of the same semi-inclusive process. The available structure function data are…
We show that simple Regge pole fits to the imaginary and the real part of the elastic amplitude in pp and pbar p collisions give a value of 1.096+0.012-0.009 for the pomeron intercept. Preliminary results of the new global fits to all…
It is argued that $W/Z$ boson production in ultra-relativistic $pp$ collisions in the fragmentation region, subject to a kinematic cut on the boson transverse momentum $Q_\perp>Q_{\perp\min}$, with 1 GeV/c$\ll Q_{\perp\min}\ll M_{W/Z}$,…
In standard Regge theory with a pomeron intercept a(0)=1+\epsilon, the contribution of the tripe-pomeron amplitude to the t=0 differential cross section for single diffraction dissociation has the form d\sigma/dM^2(t=0) \sim…
Recent results by the authors on proton diffractive dissociation (single, double and central) in the low-mass resonance region with emphasis on the LHC kinematics are reviewed and updated. Based on the previous ideas that the contribution…
A detailed analysis of the existence of high energy secondary diffractive dips and structures in the extrapolations of the fits to the data is given. The existence of these dips and a fortiori their position is found to be rather…
Deep exclusive meson production (DEMP) reactions, such as $p(\vec{e},e'\pi^+)n$, provide opportunities to study the three-dimensional structure of the nucleon through differential cross section and beam- and target-spin asymmetry…
Current theoretical framework for the calculation of heavy quark production in $\gamma\gamma$ collisions is reviewed. The importance of including direct photon contributions up to the order $\alpha^2\alpha_s^2$ and of the proper choice of…
The implications of the positivity constraint on the presently unknown polarized structure function of the photon, $g_1^{\gamma}(x,Q^2)$, are studied in detail. In particular the non-trivial consequences of this constraint,…
We show that the previously introduced CKMT model, based on conventional Regge theory, gives a good description of the HERA data on the structure function F_2^D for large rapidity gap (diffractive) events. These data allow, not only to…