Related papers: Exclusive diffractive photoproduction of dileptons…
We investigate the exclusive photoproduction of a heavy timelike photon which decays into a lepton pair, gamma p -> l+ l- p. This can be seen as the analog of deeply virtual Compton scattering, and we argue that the two processes are…
The amplitude for $\gamma p \to \phi p$ is calculated in a pQCD $k_{T}$ - factorization approach. The total cross section for this process is compared with HERA data. Total cross section, as a function of photon-proton energy and photon…
Exclusive photoproduction of dileptons, gamma p ->l+ l- p, will be measured in ultraperipheral collisions at LHC. The mechanism where the lepton pair comes from a heavy timelike photon radiated from a quark interferes with the pure QED…
The forward photoproduction amplitude for gamma p to Upsilon p is calculated in a pQCD k_t-factorization approach with an unintegrated gluon distribution constrained by inclusive deep-inelastic structure functions. The total cross section…
The amplitude for photoproduction gamma p -> \Upsilon p is calculated in a pQCD k_\perp-factorization approach. The total cross section for diffractive \Upsilon's is compared to recent HERA data. The amplitude is used to predict the cross…
The amplitude for $\gamma p \to J/\psi p$ ($\gamma p \to \psi' p$) is calculated in a pQCD $k_{T}$-factorization approach. The total cross section for this process is calculated for different unintegrated gluon distributions and compared…
The dominant mechanism for the central exclusive production of vector meson in $p p$ and $p \bar p$ collisions is the $\gamma$ $I P$ fusion. As a building block for the pp reaction, the amplitude for photoproduction $ \gamma p \to V p $ is…
The dilepton production in diffractive and exclusive processes at forward rapidities considering ultraperipheral $PbPb$ collisions at the LHC is investigated. Predictions for the $e^+ e^-$, $\mu^+ \mu^-$ and $\tau^+ \tau^-$ cross sections…
The amplitude for $\gamma p \to V p$, where $V$ is a $J/\psi$ or $\Upsilon$ ground state or excited vector meson, is calculated in a pQCD $k_{T}$-factorization approach. We use this amplitude to predict the cross section for exclusive…
We study the diffractive production of photons in gamma-p and gamma-gamma collisions. We specifically compute the rates for gamma*-p -> gamma-X and for gamma*-gamma* -> gamma-gamma, where X denotes the proton dissociation. We focus on the…
The reactions gamma p -> K+ Lambda and gamma p -> K* Lambda are analyzed within perturbative QCD, allowing for diquarks as quasi-elementary constituents of baryons. The diquark-model parameters and the quark-diquark distribution amplitudes…
We extend the k_\perp-factorization formalism for exclusive photoproduction of vector mesons to the production of electroweak Z^0 bosons. Predictions for the gamma p \to Z^0 p and p p \to p p Z^0 reactions are given using an unintegrated…
In this paper we estimate the production of dimuons ($\mu^+ \mu^-$) in exclusive photon -- photon ($\gamma \gamma$) and diffractive Pomeron - Pomeron $(I\!P I\!P)$, Pomeron - Reggeon $(I\!P I\!R)$ and Reggeon - Reggeon $(I\!R I\!R)$…
We discuss central exclusive diffractive production of light mesons in the reactions $pp \to pp\pi^{+}\pi^{-}$ and $pp \to ppK^{+}K^{-}$. The calculation is based on a tensor-pomeron approach. We include a purely diffractive dipion…
Using the high energy color dipole approach, we study the exclusive photoproduction of lepton pairs. We use simple models for the elementary dipole-hadron scattering amplitude that captures main features of the dependence on atomic number…
Production of lepton pairs in gamma p -> e-e+ p reaction is studied at photon energies up to 1 GeV. We show that even if lepton charge is not measured there are extensive kinematical regimes where the nuclear process dominates over the…
We discuss diffractive dissociation of gluons into heavy quark pairs. The particular mechanism is similar to the diffractive dissociation of virtual photons into quarks. The amplitude for the $g p \to Q \bar Q p$ is derived in the impact…
We calculate differential distributions for the $p p \to p p \gamma$ reaction at the LHC energy $\sqrt{s} = 14$ TeV. We consider diffractive classical bremsstrahlung mechanisms including effects of non point-like nature of protons. In…
In this letter we estimate the contribution of the double diffractive processes for the diphoton production in $pp$ collisions at the Large Hadron Collider (LHC). The acceptance of the central and forward LHC detectors is taken into account…
We discuss the mechanism of dilepton production in proton-proton scattering via fusion of virtual photons with identification of one proton on either side. This is relevant for the ATLAS+AFP and CMS+PPS at the LHC. Transverse momenta of the…