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A. V. Berezhnoy

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

At least 37 records · Page 2Linked to original sources
arXiv2013

The observation possibility of $B_c$ excitations at LHC

It is shown that in the decays $B_c(2P)\to B_c^* γ^\mathrm{hard}$, $B_c(3P)\to B_c^* γ^\mathrm{hard}$ and $B_c(2S)\to B_c^* +π^+π^-$ followed by the decay $B_c^*\to B_c +γ^\mathrm{soft}$ the loss of the soft photon $γ^\mathrm{soft}$ do not wash out peaks from the initial excitations. The relative yields of $B_c^*$, 2P-wave, and 3P-wave states of $B_c$ meson at LHC are estimated as function of transverse energy of emitted photon $γ^\mathrm{hard}$. It is pointed out, that the decays $B_c(2S) \to B_c(B_c^*)+π^+π^-$ could provide a new information about a $σ$ resonance nature.

hep-ph↗
arXiv2012

$Υ$-meson pair production at LHC

Theoretical predictions for $pp\to 2 Υ+X$ cross section at $\sqrt{s}=8$ TeV for the LHCb and ATLAS kinematical conditions are obtained. A possibility to observe the new hypothetical particles containing two valence $b$-quarks and two valence $\bar{b}$-quarks is discussed.

hep-ph↗
arXiv2012

Associated production of $J/ψ$-mesons and open charm and double open charm production at the LHC

Theoretical predictions of cross sections and properties of the $J/ψ$-meson production in association with an open charm hadron and formation of two open charm hadrons from two $c\bar{c}$ pairs in the LHC conditions are presented. Processes in both single and in double parton scattering mechanisms are included into consideration. Special attention is paid to the kinematic limits of the LHCb detector for which comparison with the newest experimental data is carried out.

hep-ph↗
arXiv2011

Bc -> J/psi(Bs,Bs*)+ n pi Decays

The Bc -> J/psi(Bs,Bs*)+ n pi decay amplitudes are calculated in the frame work of factorization model, which allows to represent this processes as Bc decay into J/psi Bs+W* followed by the virtual W*-boson decay into the final set of pi mesons. The module for the generation of Bc meson decays into J/psi + n pi and Bs(*) + n pi (n <= 3) is implemented into the GAUSS program package of the LHCb Collaboration.

hep-ph↗
arXiv2011

Tetraquarks composed of 4 heavy quarks

In the current work spectroscopy and possibility of observation at the LHC of tetraquarks composed of 4 heavy quarks is discussed. Tetraquarks concerned are T_{4c}=[cc][cc]$, T_{4b}=[bb][bb] and T_{2[bc]}=[bc][bc]. By solving nonrelativistic Schroedinger equation masses of these states are found with the hyperfine splitting accounted for. It is shown that masses of tensor tetraquarks T_{4c}(2++) and T_{2[bc]}(2++) are high enough to observe these states as peaks in the invariant mass distributions of heavy quarkonia pairs in pp -> T_{4c}+X -> 2J/ψ+X, pp -> T_{2[bc]}+X -> 2B_{c}+X and pp -> T_{2[bc]}+X -> J/ψΥ(1S)+X channels while T_{4b} is under the threshold of decay into a vector bottomonia pair.

hep-ph↗
arXiv2011

Double J/psi-meson Production at LHC and 4c-tetraquark state

The article is devoted to double J/psi-meson production at LHC. Theoretical predictions for pp -> 2J/psi+X cross section at sqrt{s}=7 TeV for different kinematical restrictions are presented. Special attention is payed to possible contribution of novel particles -- tetraquarks build from four c-quarks. According to presented in our article estimates, it is quietly possible to observe at least one of these state (tensor meson) experimentally.

hep-ph↗
arXiv2011

BC_NPI module for the analysis of Bc -> J/psi +n pi and Bc -> B_s +n pi decays within the EvtGen package

The module for the generation of $B_c$ meson decays into $J/ψ+ nπ$ and $B_s^{(*)} + nπ$ ($n\le 4$) is implemented into EvtGen program package. The decay amplitudes are calculated in the frame work of factorization model. Within this approach the decay can be represented as $B_c$ decay into $J/ψ(B_s)+W^*$ followed by the virtual $W^*$-boson decay into the final set of $π$-mesons. The described calculation technique allows to adopt the parameters of $W^*\to nπ$ transition from the analysis of $τ$ decay into $ν_τ+nπ$. Comparison with available theoretical predictions is performed.

hep-ph↗
arXiv2008

Lepton pair production in muon scattering by nucleus

Coherent production of lepton pair in muon scattering by nucleus is considered. With the help of different approaches (equivalent photon approximation, direct numerical and analytical calculations) we obtain total cross section of this reaction and distributions over invariant masses of final leptons. Special attention is paid to influence of final lepton identity on total and differential cross sections. We also study the role of coherence condition. Total cross sections of charmonia production in muon interaction with electromagnetic field of nucleus are also presented.

hep-ph↗
arXiv2005

Charge asymmetry in the photonic production of charmed mesons

Charge asymmetries for the charm meson production ($D^{*+}$--$D^{*-}$, $D^{*0}$--$\bar D^{*0}$ and $D^+_s$--$\bar D^-_s$) have been estimated for the COMPASS kinematic conditions in the framework of perturbative recombination model. Mass corrections have been taken into account in the calculations. The large asymmetry for $D^+_s$--$\bar D^-_s$ production has been predicted.

hep-ph↗
arXiv2004

Color flows for the process gg --> Bc + c + b-bar

The contributions of different color flows into the gluonic Bc-meson production cross section has been calculated. This study is essential to simulate Bc-meson production with the help of Pythia program. The essence of matter is that in the frame work of the Lund model used by Pythia the hadronization way of the final partons and hadronic remnants depends on the color flow type. The modified method for calculation of the color flow contributions has been proposed.

hep-ph↗
arXiv2004

Exlusive charmed meson pair production

The experimental data of BELLE Collaboration on the exclusive charmed meson pair production in the process of monophotonic $e^+e^-$-annihilation ($e^+e^-\to γ^* \to D\bar D$) has been studied. It has been shown that these data is described satisfactorily in the frame work of constituent quark model. Our studies have demonstrated that the central production process $e^+e^-\to e^+e^-γγ\to e^+e^-D\bar D +X$ and the process of monophotonic $e^+e^-$-annihilation yield comparable numbers of the charmed meson pairs.

hep-ph↗
arXiv2004

Bc photoproduction at HERA collider

The B_c photoproduction at HERA has been considered in the frame work of the pQCD. The estimated value of the total production cross section of Bc+, Bc*+, Bc- and Bc*- mesons is about 5 pb. Higher excitations yield about 30% to the total cross section. Thus for integrated HERA luminosity 1 fb-1 about 7000 Bc mesons will be produced.

hep-ph↗
arXiv2003

Processes $e^+e^- \to c \bar c c \bar c$ and $e^+e^- \to J/ψ+gg$ at $\sqrt{s}=10.59$ GeV

BELLE Collaboration data for $J/ψ$ inclusive production in the processes $e^+e^-\to J/ψ+gg$ and $e^+e^-\to J/ψ+c\bar c$ have been discussed. These data have been compared with the predictions of two pQCD methods: the former method use the information about the $J/ψ$ wave function, the latter one do not use such information and is based on the quark-hadron duality hypothesis. Both these calculation methods lead to essential discrepancy between the theoretic predictions and the experimental data. The production cross section dependence on effective gluon mass has been investigated for the process $e^+e^-\to J/ψ+gg$. The production cross section of doubly charmed baryons $Ξ^{*}_{cc}$ has been estimated.

hep-ph↗