Related papers: Single eta production in heavy quarkonia: breakdow…
Hadron collider cross sections for tt~ production and di-lepton, single-lepton and all-jet decays with up to 2 additional jets are calculated using complete LO matrix elements with 6-, 7- and 8-particle final states. The fixed-width,…
The bottomonium spectrum is systematically studied within an unquenched quark model. Based on a good description of both the masses and widths for the well-established states, we further give predictions for the higher $S$-, $P$-, and…
Quarkonia (J/Psi, Psi', Upsilon) production provides a sensitive probe of gluon distributions and their modification in nuclei; and is a leading probe of the hot-dense (deconfined) matter created in high-energy collisions of heavy ions. I…
We perform the first complete one-loop study of exclusive photoproduction of vector quarkonia off protons in Collinear Factorisation (CF) including the scale evolution of the Generalised Parton Distributions (GPDs). We confirm the…
In this work, we review the experimental and theoretical developments of bottomonia production in proton+proton and heavy-ion collisions. The bottomonia production process is proving to be one of the most robust processes to investigate the…
The suppression of bottomonia in ultrarelativistic heavy-ion collisions is a smoking gun for the production of a strongly interacting final state in ultrarelativistic heavy-ion collisions. Furthermore, these final state interactions are…
The $\Upsilon(2S)$ production and polarization at high energies is studied in the framework of $k_T$-factorization approach. Our consideration is based on the non-relativistic QCD formalism for bound states formation and off-shell…
We analyze the overlap of color-octet meson operators with the $\Upsilon$ and the $\eta_b$ and their excited states, especially the first radial excitations. Our analysis is based on NRQCD and includes all terms up to order $v^4$. We use a…
The charmonium transitions from the $\chi_{cJ}$ states to $\eta_c$ with emission of one or two pions are considered. It is shown that the only processes of such type arising in the leading order in the QCD multipole expansion are the decays…
The production of $\eta$ and $\eta^{\prime}$ mesons in photon- and hadron-induced reactions on free and quasi-free nucleons and on nuclei is reviewed. The extensive database on $\gamma N \to \eta N$, for both proton and neutron targets, is…
We calculate the masses and leptonic decay widths of the bottomonium $b\bar b$ and charmonium $c\bar c$ states in a constituent quark model where the Cornell-like potential and spin-dependent interaction are employed, with all model…
We present a measurement of the polarization observed for bottomonium states produced in p-Cu collisions at sqrt(s)=38.8 GeV. The angular distribution of the decay dimuons of the Upsilon(1S) state show no polarization at small xF and pT but…
In this paper we investigate the inclusive associated production of {\Upsilon} + {\gamma} at the hadron collider. We calculate the color-singlet sub-processes and all three color-octet sub-processes at the next-to-leading order. Seven sets…
In this work, we propose a possible experimental research topic on the $\Upsilon(6S)\to \Upsilon(nS)\eta^{(\prime)}$ ($n=1,2,3$) transitions. Considering the hadronic loop effect from the intermediate $S$-wave $B_{(s)}$ and $B_{(s)}^*$…
Photoproduction of $\eta$-mesons off deuteron is studied within the Alt-Grassberger-Sandhas formalism for different parameters of $\eta N$ interaction. The calculations revealed peaks in the energy dependence of the total cross-section.
The radiative decays $\eta'(\eta)\rta\gamma\gamma$ are discussed. The modifications of the conventional PCAC formulae due to the gluonic contribution to the flavour singlet axial anomaly are given. The decay constants satisfy a modified…
We present a novel study on the inclusive production of a heavy quarkonium ($J/\psi$ or $\Upsilon$), in association with a light-flavored jet, as a test field of the high-energy QCD dynamics. The large transverse momenta at which the two…
Several fixed-target experiments reported J/$\psi$ and $\Upsilon$ polarization measurements, as functions of Feynman $x$ ($x_{\rm F}$) and transverse momentum ($p_{\rm T}$), in three different polarization frames, using different…
In this paper we propose an approach which demonstrates the dependence of quarkoni production on the multiplicity of the accompanying hadrons. Our approach is based on the three gluons fusion mechanism, without assuming the multiplicity…
The electroproduction of eta and eta' mesons on the proton and the neutron is investigated at tree level within the framework of U(3) chiral perturbation theory. In addition to the Born terms low-lying resonances such as the vector mesons…