This is a review of recent trends and problems in high-energy diffraction, including elastic and inelastiuc scattering.
The presentation will be based on our paper in preparation
[1].
We discuss production of pairs of $J/\psi$ quarkonia in
proton-proton collisions in the context of recent results obatained
at the LHC at large transverse momenta.
The leading-order $O(\alpha_s^4)$ contribution
is calculated in both collinear and the $k_t$-factorization approach
with the KMR unintegrated gluon distributions....
We discuss single-diffractive production of dijets at high energies.
For a first time we propose a $k_t$-factorization approach to the diffractive processes [2].
The transverse momentum dependent diffractive parton distributions are obtained from standard (collinear) diffractive parton distributions used in the literature. In this calculation the transverse momentum of the pomeron is neglected...
We discuss different models for the spin structure of the nonperturbative
pomeron: scalar, vector, and rank-2 symmetric tensor. The ratio of single-
helicity-flip to helicity-conserving amplitudes in polarised high-energy
proton-proton elastic scattering, known as the complex r5 parameter, is
calculated for these models. We compare our results to experimental data from
the STAR...
It has been shown that AdS/CFT calculations can reproduce certain
exclusive 2-to- 2 cross sections in QCD at high energy, both for near-
forward and for fixed-angle scattering. We extend prior treatments by
using AdS/CFT to calculate both the exclusive and inclusive central
production cross section in QCD at high center-of- mass energy. We
explore consequence of conformal invariance, and...
Factorization prescriptions that allow for non-vanishing components of
the momenta of initial-state partons require matrix elements with off-shell
partons. It is well known how to define and calculate such matrix elements
at tree-level in a gauge invariant manner. We present the first steps to
arrive at one-loop amplitudes with an off-shell gluon, necessary to reach
next-to-leading order precision.
Diffractive phenomena at the LHC are studied by several collaborations there. In this paper we present our recent results connected with the current and future studies at the LHC, namely the deviation of the exponential behavior in elastic proton-proton scattering at low values of |t| and central exclusive resonance production. Although the above phenomena occur in different kinematical...
