Related papers: Prompt hadroproduction of $\eta_c(1S,2S)$ in the $…
We derive the light-front wave function (LFWF) representation of the $\gamma^{\star} \gamma^{\star} \to \eta_{c} (1S),\eta_{c}(2S)$ transition form factor $F(Q^2_1,Q^2_2)$ for two virtual photons in the initial state. For the LFWF, we use…
We present a new approach for the prompt production of quarkonia which is based on the $k_T$-factorization method. The production of even C-parity quarkonia proceeds via the fusion of two (off-shell) gluons. Especially in the kinematics of…
We review our recent results for production of $\eta_c(1S)$ and $\eta_c(2S)$ in the $\gamma^* \gamma^* \to \eta_c(1S,2S)$ fusion and in proton-proton collisions via gluon-gluon fusion. The quarkonium wave functions are calculated by solving…
In this work, we present a thorough analysis of scalar $P$-wave $\chi_{Q0}$, $Q=c,b$ quarkonia electromagnetic form factors for the $\gamma^* \gamma^* \to \chi_{Q0}$ couplings, as well as their hadroproduction observables in…
Quarkonia production in different high-energy processes has recently been proposed in order to probe gluon transverse-momentum-dependent parton distribution and fragmentation functions (TMDs in general). However, no proper factorization…
Quarkonium production in hadron collisions at low transverse momentum $q_\perp \ll M$ with $M$ as the quarkonium mass can be used for probing transverse momentum dependent (TMD) gluon distributions. For this purpose, one needs to establish…
The inclusive hadronic production of $\eta_Q$($\eta_c$ or $\eta_b$) pair is proposed to extract the transverse momentum dependent(TMD) gluon distribution functions. We use nonrelativistic QCD(NRQCD) for the production of $\eta_Q$. Under…
In the framework of the $k_T$-factorization, the prompt production of $\eta_c$ mesons at the LHC conditions is studied. Our consideration is based on the off-shell amplitudes for hard partonic subprocesses and on the nonrelativistic QCD…
In this paper, we investigate the inclusive diffractive hadroproduction for $\rm \eta_{c}$ and $\rm \eta_{b}$ at the LHC energies. Based on the NRQCD factorization formalism and the resolved-Pomeron model for the quarkonium production…
The amplitude for production of a single photon associated with quark pair in the fusion of two off-shell gluons is calculated. The matrix element found is applied to the inclusive prompt photon hadroproduction at high energies in the…
We study exclusive production of scalar $\chi_{c0}\equiv \chi_c(0^{++})$ and pseudoscalar $\eta_c$ charmonia states in proton-proton collisions at the LHC energies. The amplitudes for $gg \to \chi_{c0}$ as well as for $gg \to \eta_c$…
Inspired by the recent measurements of the $\eta_c$ meson production at LHC, we investigate the relativistic correction effect for the fragmentation function of the gluon into $\eta_c$, which constitutes the crucial nonperturbative elements…
Inclusive production of a quarkonium $\eta_{c,b}$ in hadron collisions at low transverse momentum can be used to extract various Transverse-Momentum-Dependent(TMD) gluon distributions of hadrons, provided the TMD factorization for the…
We study the prompt photon hadroproduction at the LHC with the $k_T$-factorization approach and the $qg^* \to q\gamma$ and $g^*g^* \to q\bar q\gamma$ partonic channels, using three unintegrated gluon distributions which depend on gluon…
We study the production of prompt photons at high energy in the framework of the k_T-factorization approach. The amplitude for production of a single photon associated with quark pair in the fusion of two off-shell gluons is calculated.…
We discuss prompt production of $J/\psi$ mesons in proton-proton collisions at the LHC within NRQCD k$t$-factorization approach using Kimber-Martin-Ryskin (KMR) and Kutak-Stasto (KS) unintegrated gluon distribution (UGDF). We include both…
We reconsider the prompt photon photoproduction at HERA in the framework of the $k_T$-factorization QCD approach. The proposed method is based on the ${\cal O}(\alpha^2\alpha_s)$ amplitudes for $\gamma q\to\gamma gq$ and $\gamma…
The transverse momentum distributions for inclusive $\eta_{c,b}$ meson described by gluon-gluon interactions from photoproduction processes in relativistic heavy ion collisions are calculated. We considered the color singlet (CS) and color…
In the framework of kt-factorization approach,the production of prompt $\chi_c$ mesons in pp collisions at the LHC energies is studied. Our consideration is based on the off-shell amplitudes for hard partonic subprocesses…
We present calculations of heavy quark and quarkonium production at CERN LEP2 in the k_T-factorization QCD approach. Both direct and resolved photon contribution are taken into account. The conservative error analisys is performed. The…