c-quark decay modes in B_c-meson

We discuss the possibility for observing $B_c$ mesons in decay channels with $B_s$ in final state.Comment: 6 pages, 1 table; refrences adde

Possible nature of Z+(4430)Z^+(4430)

We discuss exotic states X(3872) and $Z^+(4430)$, observed recently in experiment Belle. The QCD-string based explanation is suggested.Comment: 5 pages, 6 figure

Simultaneous production of charmonium and bottomonium mesons at LHC

Inclusive production of $\Upsilon J/\psi$ pair in proton-proton interation at LHCb is considered. This process is forbidden at leading order of perturbation theory, so such channels as double parton scattering, $\chi_b\chi_c$ pair production with subsequent radiative decays of $P$-wave quarkonia, contributions of color-octet states, and NLO corrections are studied in details. For all these channels we present theoretical predictions of total cross sections at LHCb and distributions over different kinematical variables. According to presented in the paper results, double parton interaction gives main contribution to the cross section of the considered reaction.Comment: minor changes, some references adde

Affine Transformations of Loop Nests for Parallel Execution and Distribution of Data over Processors

The paper is devoted to the problem of mapping affine loop nests onto distributed memory parallel computers. A method to find affine transformations of loop nests for parallel execution and distribution of data over processors is presented. The method tends to minimize the number of communications between processors and to improve locality of data within one processor. A problem of determination of data exchange sequence is investigated. Conditions to determine the ability to arrange broadcast is presented.Comment: 9 page

Production of J/ψ+χcJ/\psi + \chi_c and J/ψ+J/ψJ/\psi + J/\psi with real gluon emission at LHC

In the present work we study production of $J/\psi + \chi_c$ and $J/\psi + J/\psi$ in LHC. The first process is forbidden at the leading order in gluon fusion due to the $C$-parity conservation, and the first non-vanishing contribution is given by the process with additional emission of real gluon. Considering the direct production of $J/\psi + J/\psi$, where the leading order is allowed, we have found that the contribution from the higher order process with real gluon emission is comparable and even more significant than the leading order. Moreover, account of this higher order effect dramatically changes kinematical distributions. Through the present paper we study in details different channels of paired $J/\psi + J/\psi$ production: direct $J/\psi + J/\psi$ production, feed-down from $J/\psi + \chi_c$ channel, double parton scattering. We also try to find kinematical distributions that are most suitable to separate these different channels.Comment: minor changes, some references adde

Hadronic Production of chicchi_c-mesons at LHC

Hadronic production of $P$-wave charmonium states $\chi_{cJ}$ in hadronic interaction is considered. Using experimental results of CDF and LHCb collaborations we show, that contributions of color-singlet components are dominant. As for color-octet mechanism, we show, that contributions from $P$-wave states can also be observed, while $S$-wave states can be neglected. The best experimental observables that give information about relative importance of color-singlet and color-octet components are the ratios $\chi_{c2}/\chi_{c1}$ and $\chi_{c0}/\chi_{c1}$.Comment: 14 pages, 6 figures, 2 table

Production of χc\chi_c- and χb\chi_b-mesons in high energy hadronic collisions

This paper is devoted to phenomenological study of $\chi_{c,b}$-mesons production in high energy hadronic collisions in the framework of NRQCD. We analyze all available experimental data on $\chi_c$-mesons production and extract non-perturbative NRQCD matrix elements from fitting the data. We show, that measured $p_T$-spectrum of $\chi_c$-mesons is mainly formed by color singlet components, while $\sigma(\chi_{c2})/\sigma(\chi_{c1})$ ratio depends strongly on color octet matrix elements; this ratio becomes a highly sensitive tool to study contribution of different terms from the NRQCD expansion. Obtained using NRQCD scaling rules predictions for $\chi_b$-mesons cross sections are also given.Comment: 10 pages, 7 figure

Analytical calculation of heavy quarkonia production processes in computer

This report is devoted to the analytical calculation of heavy quarkonia production processes in modern experiments such as LHC, B-factories and superB-factories in computer. Theoretical description of heavy quarkonia is based on the factorization theorem. This theorem leads to special structure of the production amplitudes which can be used to develop computer algorithm which calculates these amplitudes automatically. This report is devoted to the description of this algorithm. As an example of its application we present the results of the calculation of double charmonia production in bottomonia decays and inclusive the $\chi_{cJ}$ mesons production in pp-collisions.Comment: minor change

Charmed hadrons production in high-energy Σ−\Sigma^- beam

We present the calculation of the inclusive x_F-distributions of charmed hadrons, produced in high-energy $\Sigma^-$-beam. Our calculation is based on the modified mechanism of charmed quarks fragmentation as well as on the mechanism of c-quark recombination with the valence quarks from initial hadrons.Comment: 6 pages, 6 figures, LaTe

On Mechanism of Charmed c-Quarks Fragmentation in Hadronic Collisions

We propose a modification of the mechanism of charmed quarks fragmentation into $D$ mesons in hadronic collisions. It is shown that the distinction in valence quark distributions in the initial $\pi^{\pm}$ and $K^{\pm}$ mesons leads to different inclusive spectra of $D$ and $D_s$ mesons produced in $\pi^{\pm}$ and $K^{\pm}$ beams.Comment: 18 pages, LaTeX, epsfig, 5 figure