Excited ρ\rho mesons in Bc→ψ(′)KKSB_{c}\to\psi^{(')}KK_{S} decays

In the presented paper exclusive decays $B_{c}\to J/\psi KK_{S}$ and $B_{c}\to\psi(2S)KK_{S}$ are analyzed. It is shown that contributions of the excited $\rho$ mesons should be taken into account to describe these decays. It is also shown that, unlike the corresponding $\tau$ lepton decays, peaks in $m_{KK_{S}}$ distributions caused by these resonances are clearly seen and can be easily separated. Theoretical predictions for the branching fractions of the reactions and $m_{\psi K}$ distributions are also presented.Comment: 6 pages, 5 figure

J/ΨΥJ/\Psi \Upsilon Production 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: 8 pages, 4 figures, 1 table. To be published in the proceedings of CHARM-2015, Detroit, MI, 18-22 May 201

Production of K mesons in exclusive BcB_c decays

The paper is devoted to investigation of $K$ mesons production in exclusive $B_{c}$ decays $B_{c} \to \psi^{(')}K^{+}K^{-}\pi^{+}$ and $B_{c} \to \psi^{(')}K^{+}\pi^{+}\pi^{-}$. In the framework of resonance approximation we obtain theoretical predictions for branching fractions of these decays and present distributions over different kinematical variables.Comment: minor changes, typos correcte

Leading order NRQCD and Light-Cone Analysis of Exclusive Charmonia Production in Radiative ZZ-boson Decays

The presented paper is devoted to theoretical analysis of charmonium mesons $\eta_c$, $J/\psi$, $\chi_{c0,1,2}$, and $h_c$ production in exclusive radiative $Z$ boson decays in the frameworks of Nonrelativistic Chromodynamic and amplitude expansion on the light-cone. In the framework of light-cone expansion amplitudes and widths of all processes are described with one universal relation. It is interesting to note that from this relation it follows automatically which component of $Z$ boson (either vector or axial) gives contribution to the width of the particular decay. It is shown that the effect of internal quark motion almost doubles theoretical predictions for production of $S$-wave charmonia and $\chi_{c1}$ meson.Comment: Minor changes, some references adde

Charmonia Production in W→(ccˉ)Ds(∗)W\to (c\bar{c}) D_{s}^{(*)} Decays

In the presented paper production of charmonium state $\mathcal{Q}$ in exclusive $W\to\mathcal{Q} D_{s}^{(*)}$ decays is analyzed in the framework of both leading order Nonrelativistic Quantum Chromodynamics (NRQCD) and light-cone expansion (LC) models. Analytical and numerical predictions for the branching fractions of these decays in both approaches are given. The typical value of the branching fractions is $\sim 10^{-11}$ and it turns out the LC results are about 4 times lager than NRQCD ones, so the effect of internal quark should be taken into account. Some estimates of color-octet contributions are presented and it is shown, that these contributions could be comparable with color-singlet results.Comment: 9 pages, 4 figures, 2 table

Initial state radiation corrections to double charmonium production in one-photon electron-positron annihilation

In this paper initial state radiation corrections to double production of charmonium mesons on one-photon electron-positron annihilation at center of mass energy \sqrt{s}=10.6\GeV are studied. It is shown, that these corrections have noticeable effect and must be taken into consideration.Comment: 5 pages, 5 figures, minor change

On double 1−−1^{--} charmonium production through two-photon \e^+ e^- annihilation at s=10.6GeV\sqrt{s}=10.6 GeV

Recent measurements of the Belle Collaboration of the exclusive production of two charmonia in the $e^+e^-$ annihilation differ substantially from theoretical predictions. Recently it was suggested that a significant part of this discrepancy can be explained by the process $e^2e^- --> 2J/psi$ and value for its cross-section was published. In this paper it is shown, that these results are incorrect and the values for the cross-sections of the production of different vector charmonia are presented.Comment: 4 pages, 2 figures; minor change

Charmonium production in hadronic experiments at the energy 70 GeV

The production of the charmonium states in hadronic experiments is considered in NLO at the strong coupling constant. It is shown, that such an approach solves some significant problems, arising when only leading order processes are considered. In particular, in such a consideration distributions over the transverse momentum of the final charmonium can be obtained. There appears also a natural explanation to the existence of $\chi_{c1}$-meson in final state, that is observed experimentally and cannot be produced in leading order processes.Comment: 28 pages, 13 figure

Weak decays of doubly heavy baryons: decays to system of π\pi mesons

In the presented article we consider exclusive weak decays of doubly heavy baryons with spin $J=1/2$ with production of leptonic pair or a set of light mesons. Using QCD factorization theorem and spectral functions approach we obtain theoretical predictions for the partial probabilities of these decays and distributions over various kinematic variables. According to the obtaining results partial probabilities of some of researched decays are large enough to be observed experimentally.Comment: Small changes (spectral functions' parametrization updated, some of the branching fractions have slightly change, affiliation information is updated). Accepted for publication in Phys.Rev.

Double Charmonia Production in Exclusive ZZ Boson Decays

This article is devoted to systematic analysis of double charmonium production in exclusive $Z$ boson decays in the framework of Nonrelativistic Quantum Chromodynamic (NRQCD) and leading twist light-cone (LC) models. Theoretical predictions for branching fractions of all considered decays are presented. According to obtained results in the case of allowed by helicity suppression rule processes the effect of internal quark motion increases the branching fraction by a factor 1.5, while for forbidden reactions LC predictions are strictly zero, while NRQCD ones are significantly smaller than for allowed.Comment: 10 pages, 2 figures, 2 tables. arXiv admin note: substantial text overlap with arXiv:1706.0409