Related papers: $J/\psi + c + \bar{c}$ Photoproduction in $e^+ e^-…
As an important sequential work of the S-wave $B_c^{(*)}$ ($^1S_0(^3S_1)$) meson production at the large hadron electron collider (LHeC), we investigate the production of the P-wave excited $B_c^{**}$ states ($^1P_1$ and $^3P_J$ with…
We extend a previous study of photoproduction of exotic baryon resonances to the reaction $\gamma + d \to J/\psi + n + p$, which permits simultaneous investigation of the reactions $\gamma + p \to P_c^+ \to J/\psi~p$ \hbox{($n$ spectator)}…
We report the calculation of the process $e^+ e^- \to J/\psi J/\psi$ up to next-to-next-to-leading order (NNLO) at a center-of-mass (CM) energy of $\sqrt{s}=10.58$ GeV. We employ an improved NRQCD factorization approach, decomposing the…
Recent measurements of J/$\psi$ photoproduction based on data from ultra-peripheral Pb-Pb and p-Pb collisions recorded by the ALICE experiment during Run 2 of the LHC are presented. Photoproduction as a photon-induced process is sensitive…
We present a rigorous next-to-leading order analysis of J/psi yield and polarization within the factorization theorem of nonrelativistic QCD (NRQCD). To the orders considered, this framework depends on three free parameters, the color-octet…
Polarizations of the prompt $J/\psi$'s produced in the $e^+e^-$ annihilation at CLEO energy ($\sqrt{s} = 10.58$ GeV) are considered in the framework of NRQCD factorization formalism. We find that the $J/\psi$ polarization has strong…
The inclusive $J/\psi$ production in $e^+ e^- \to J/\psi c\bar c$ at B factories is one of the most challenging open problems in heavy quarkonium physics. The observed cross section of this double charm production process is larger than…
Recent measurements by the Belle Collaboration of the exclusive production of two charmonia in e^+ e^- annihilation differ substantially from theoretical predictions. We suggest that a significant part of the discrepancy can be explained by…
One of the outstanding problems in J/\psi physics is a systematic understanding of the differential photo-production cross section dsigma/dz(gamma + p -> J/psi + X), where z= E_psi/E_gamma in the proton rest frame. The theoretical…
We discuss the role of $c \bar c g$-Fock states in the diffractive photoproduction of $J/\psi$-mesons. We build on our earlier description of the process in the color-dipole approach, where we took into account the rescattering of $c \bar…
The ALICE collaboration has made the first measurement at the LHC of J/$\psi$ photoproduction in ultra-peripheral Pb-Pb-collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV. The J/$\psi$ is identified via its dimuon decay in the forward rapidity…
In this work, we present a next-to-leading-order (NLO) study of $J/\psi + \gamma$ production via photon-photon fusion in proton-proton ultraperipheral collisions (UPCs) at $\sqrt{s_{NN}} = 14$ TeV. The calculation is performed within the…
In heavy quarkonium production, the measured ratio $R_{c \bar c}=\sigma[J/\psi+ c\bar c + X]/\sigma[J/\psi +X]$ at B factories is much larger than existing theoretical predictions. To clarify this discrepancy, in nonrelativistic QCD (NRQCD)…
In this paper we investigate the production of pentaquark states in the photon -- proton interactions present in hadronic collisions at the RHIC and LHC. We consider two phenomenological models for the $J/\Psi$ photoproduction that consider…
The prediction of single-spin asymmetry in inelastic photoproduction of $J/\psi$ in $ep^\uparrow$ collision is presented. At next-to-leading order, the dominating process is photon-gluon fusion, $\gamma+g\rightarrow J/\psi+g$ for the…
We analyze the polarization observables of J/psi photoproduction at next-to-leading order (NLO) within the factorization formalism of nonrelativistic quantum chromodynamics (NRQCD). This is the first NLO study of heavy-quarkonium…
We employ a small $x$ Color Glass Condensate (CGC)+ Non-Relativistic QCD (NRQCD) formalism to compute $J/\psi$ production at low $p_\perp$ in proton-proton collisions at collider energies. Very good agreement is obtained for total…
Following HERA experiments our interest is focused, in the present paper, on charmonium production in lepton-proton collisions. Inelastic J/\psi electroproduction is quite difficult to be measured due to the low rates of events; almost all…
We revisit inclusive J/psi and Upsilon photoproduction at lepton-hadron colliders, namely in the limit when the exchanged photon is quasi real. Our computation includes the next-to-leading-order (NLO) alpha_s corrections to the…
We calculate the production and polarization of direct $J/\psi$ in the improved color evaporation model in $e+p$ photoproduction. We present the production as functions of transverse momentun, mass of the hadronic final state, and…