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A. V. Luchinsky

Publications and source records attributed to A. V. Luchinsky.

At least 19 recordsLinked to original sources
arXiv2022

Multiple Charged Meson Production in Exclusive $B_{c}$ Decays: $K+4π,$$KK+3π$, $7π$ Cases

Theoretical analysis of three exclusive decays, $B_{c}\to J/ψ+\mathcal{R},$where $\mathcal{R}=K+4π,$$KK+3π$, or $7π$, is given. Using the factorization method and the resonance approximation (methods proved to be very useful in the analysis of some other similar decays), we have obtained analytical expressions of the required amplitudes and created distributions over some interesting mass combinations. Presented results could be used for comparison with forthcoming experimental data and better understanding of the nature of heavy quarkonia.

hep-ph↗
arXiv2020

Exclusive Decays of the Doubly Heavy Baryon $Ξ_{bc}$

Exclusive decays of the $Ξ_{bc}^+$ with light mesons production, $Ξ_{bc}^+\toΞ_{cc}^{++}\mathcal{R}$ are analyzed. In the framework of the factorization model the matrix elements of the considered reactions are written as a product of $Ξ_{bc}\toΞ_{cc}W$ and $W\to\mathcal{R}$ transition amplitudes. As a result theoretical and experimental investigation of these decays allow us to test the physics of heavy and light quarks' sectors. Presented are the branching fractions of these reactions, as well as the distributions over the invariant mass of the light system and some other kinematical variables. Our calculations show that the probabilities of the considered reactions are high enough, so presented results could help with observation of yet unseen $Ξ_{bc}$ baryon.

hep-ph↗
arXiv2019

Weak decays of doubly heavy baryons: decays to system of $π$ 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.

hep-ph↗
arXiv2019

$B_c$ excitations at LHC experiments

The $2S$ $B_c$ states observed by ATLAS, CMS and LHCb Collaborations are discussed. The observation perspectives of $B_c^*$, $2P$ wave, $3P$ wave and $D$ wave states of $B_c$ at LHC experiments are estimated.

hep-ph↗
arXiv2018

Excited $ρ$ mesons in $B_{c}\toψ^{(')}KK_{S}$ decays

In the presented paper exclusive decays $B_{c}\to J/ψKK_{S}$ and $B_{c}\toψ(2S)KK_{S}$ are analyzed. It is shown that contributions of the excited $ρ$ mesons should be taken into account to describe these decays. It is also shown that, unlike the corresponding $τ$ 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 $m_{ψK}$ distributions are also presented.

hep-ph↗
arXiv2018

Doubly heavy baryons at LHC

The theoretical analysis of production, lifetime, and decays of doubly heavy baryons is presented. The lifetime of $Ξ_{cc}^{++}$ baryon recently measured by the LHCb Collaboration is used to estimate the lifetimes of other doubly heavy baryons. The production and the possibility of observation of $Ξ_{bc}$ baryon at LHC are discussed.

hep-ph↗
arXiv2018

Charmonia Production in $W\to (c\bar{c}) D_{s}^{(*)}$ 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.

hep-ph↗
arXiv2017

Double Charmonia Production in Exclusive $Z$ 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.

hep-ph↗
arXiv2017

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

The presented paper is devoted to theoretical analysis of charmonium mesons $η_c$, $J/ψ$, $χ_{c0,1,2}$, 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 $χ_{c1}$ meson.

hep-ph↗
arXiv2017

Comments on "Study of $J/ψ$ production in jets"

Recent LHCb measurements of the $J/ψ$ meson production in jets is analyzed using fragmentation jet function formalism. It is shown that disagreement with theoretical predictions for distribution over the fraction of $J/ψ$ transverse momentum $z(J/ψ)$ in the cases of prompt production can be explained if one takes into account evolution of the fragmentation function and contributions from double parton scattering mechanism.

hep-ph↗
arXiv2016

Production of $J/ψ+ χ_c$ and $J/ψ+ J/ψ$ with real gluon emission at LHC

In the present work we study production of $J/ψ+ χ_c$ and $J/ψ+ J/ψ$ 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 $J/ψ+ J/ψ$, 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 $J/ψ+ J/ψ$ production: direct $J/ψ+ J/ψ$ production, feed-down from $J/ψ+ χ_c$ channel, double parton scattering. We also try to find kinematical distributions that are most suitable to separate these different channels.

hep-ph↗
arXiv2016

Production of associated $χ_b$ and open charm at the LHC

In the present paper we study the production of $χ_b + c\bar c$ at the LHC within single parton scattering approach. A special attention payed to the feed-down from $χ_b$ states to the associated $Υ+ c\bar c$ production, which was recently studied by the LHCb. We have found that this feed-down is about percents of the total cross section seen in the experiment. It is shown that the shapes of the differential distributions are almost same as found by the LHCb except the azimuthal asymmetry, which is almost flat in the experiment. We conclude that the precise study of the single parton scattering contributions is necessary for the correct isolation of other possible production channels such as double parton scattering.

hep-ph↗
arXiv2015

$J/ΨΥ$ Production at LHC

Inclusive production of $ΥJ/ψ$ 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, $χ_bχ_c$ 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.

hep-ph↗
arXiv2015

Simultaneous production of charmonium and bottomonium mesons at LHC

Inclusive production of $ΥJ/ψ$ 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, $χ_bχ_c$ 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.

hep-ph↗
arXiv2015

Production of $η_Q$ meson at LHC

The paper is devoted to theoretical consideration of inclusive $η_{c,b}$ meson production at LHC. It is shown that existing experimental data on $η_c$ meson production at LHCb detector can be described in the framework of NRQCD formalism and color-singlet component with phenomenological value of matrix element $|R(0)|^2$ gives main contribution. Using this model we present theoretical prediction for integrated cross sections and transverse momentum distributions for inclusive $η_c$ production at other LHC detectors. The case of $η_b$ meson production at LHC is also considered.

hep-ph↗
arXiv2014

Production of $χ_c$- and $χ_b$-mesons in high energy hadronic collisions

This paper is devoted to phenomenological study of $χ_{c,b}$-mesons production in high energy hadronic collisions in the framework of NRQCD. We analyze all available experimental data on $χ_c$-mesons production and extract non-perturbative NRQCD matrix elements from fitting the data. We show, that measured $p_T$-spectrum of $χ_c$-mesons is mainly formed by color singlet components, while $σ(χ_{c2})/σ(χ_{c1})$ 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 $χ_b$-mesons cross sections are also given.

hep-ph↗
arXiv2014

Radiative $B_c$ meson decays $B_c \to γu\bar{d}$

Inclusive radiative decays $B_c\toγu\bar{d}$ are considered. It is shown that photon emission allows one to bypass the chiral suppression and leads the increase of the branching fraction by about four orders of magnitude. The estimates of exclusive decay branching fractions of $B_c$ meson into different sets of $π$ mesons are also given.

hep-ph↗