Diffractive Double-Elastic Production of η\eta' and ηc\eta_c in the pp→pXpp p \to p X p Reaction

I discuss double-diffractive (double-elastic) production of the $\eta'$ and $\eta_c$ mesons in the $pp \to p X p$ reaction within the formalism of unintegrated gluon distribution functions (UGDF). The contribution of $\gamma^* \gamma^* \to \eta'$ fusion is estimated. The distributions in the Feynman $x_F$ (or rapidity), transferred four-momenta squared between initial and final protons ($t_1$, $t_2$) and azimuthal angle difference between outgoing protons ($\Phi$) are calculated and discussed. The results are compared with the WA102 data. Predictions at higher energies are presented.Comment: a talk presented at the international conference MESON2006, Cracow, Poland, June, 2006; 5 pages, 3 figures, 1 tabl

Diffractive pQCD mechanisms of exclusive production of bbˉb \bar b dijets and W+W−W^+ W^- pairs in proton-proton collisions

We discuss central exclusive production of $W^+W^-$ pairs in proton-proton collisions at LHC. Predictions for the total cross section and differential distributions in transverse momentum of $W^{\pm}$ and $WW$ invariant mass are presented. We discuss both $\gamma \gamma \to W^+ W^-$ mechanism as well as a new mechanism of exclusive diffractive production. The amplitude for the latter process is calculated in the Durham model. We compare the two (QED and QCD) types of contributions. The diffractive contribution is only a small fraction of fb compared to the $\gamma \gamma$ contribution which is of the order of 100 fb. This opens a possibility of searches for anomalous four-boson $\gamma \gamma W^+ W^-$ coupling due to physics beyond Standard Model.Comment: invited talk at the DIS2012 workshop, Bonn, Germany, 26-30 March 201

Central meson production in diffractive reactions

I discuss double-diffractive (double-elastic) production of the $\eta'$ and $\eta_c$ mesons in the $pp \to p X p$ reaction within the formalism of unintegrated gluon distribution functions (UGDF). The contribution of $\gamma^* \gamma^* \to \eta'$ fusion is estimated. The distributions in the Feynman $x_F$ (or rapidity), transferred four-momenta squared between initial and final protons ($t_1$, $t_2$) and azimuthal angle difference between outgoing protons ($\Phi$) are calculated and discussed. The results are compared with the WA102 data. Predictions at higher energies are presented.Comment: 7 pages, 6 figures a talk at International Workshop on Diffraction in High-Energy Physics - DIFFRACTION 2006, Adamantas, Milos island, Greece, September 5-10, 200

Production of ccˉc \bar c pairs at LHC: ktk_t-factorization and double-parton scattering

We discuss charm production at LHC. The production of single $c \bar c$ pairs is calculated in the $k_t$-factorization approach. We use several unintegrated gluon distributions from the literature. Differential distributions for several charmed mesons are presented and compared to recent results of the ALICE and LHCb collaborations. Some missing strength can be observed. Furthermore we discuss production of two $c \bar c$ pairs within a simple formalism of double-parton scattering (DPS). Surprisingly large cross sections, comparable to single-parton scattering (SPS) contribution to $c \bar c$ production, are predicted for LHC energies.Comment: invited talk at DIS2012 workshop, Bonn, Germany, 26-30 March 201

New vistas in charm production

We discuss some new aspects of charm production trigerred by recent observations of the LHCb collaboration. The LHCb collaboration measured small asymmetries in production of $D^+ D^-$ mesons as well as $D_s^+ D_s^-$ mesons. Is this related to initial quark/antiquark asymmetries in the proton ? Here we discuss a scenario in which unfavored fragmentations $q/{\bar q} \to D$ and $s/{\bar s} \to D_s$ are responsible for the asymmetries. We fix the strength of such fragmentations -- transition probabilities, by adjusting to the size of the LHCb asymmetries. This has consequences for production of $D$ mesons in forward directions (large $x_F$) as well as at low energies. Large asymmetries are predicted then in these regions. We present here some of our predictions. Consequences for high-energy neutrino production in the atmosphere are discussed and quantified. The production of $\Lambda_c$ baryon at the LHC is disussed. Large deviations from the independent-parton fragmentation picture are found.Comment: 10 pages, 13 figures invited talk at ISMD2018, Singapore, September 4-7, 201