Related papers: Single eta production in heavy quarkonia transitio…
In this work, we propose the $4S$-$3D$ mixing scheme to assign the $\Upsilon(10753)$ into the conventional bottomonium family. Under this interpretation, we further study its hidden-bottom hadronic decays with a $\eta^{(\prime)}$ or…
We study the $\eta$-photoproduction focusing on the new nucleon resonance which was observed at $\sqrt{s}=1675$ MeV with a narrow decay width ($\sim 10$ MeV) in the recent GRAAL experiment. Using an effective Lagrangian approach, we compute…
Thirty years ago, the suppression of quarkonium production in heavy-ion collisions was first proposed as an unambiguous signature for the formation of a Quark-Gluon Plasma. Recent results from the LHC run 2 have led to an unprecedented…
Lepton pairs with opposite charges can form bound states known as ``leptonium'' through quantum electrodynamic interactions. Heavy quarkonia such as $J/\psi$ are abundantly produced at facilities like BESIII and the future Super Tau-Charm…
We review the present status in the theoretical and phenomenological understanding of charmonium and bottomonium production in heavy-ion collisions. We start by recapitulating the basic notion of "anomalous quarkonium suppression" in…
The production rate of bottom quarks at hadron colliders exceeds the expectations of next-to-leading order perturbative quantum chromodynamics. An additional contribution from pair-production of light gluinos, of mass 12 to 16 GeV, with…
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…
We compute power-suppressed corrections to the \eta\gamma and \eta^{\prime}\gamma transition form factors Q^2F_{\eta(\eta^{\prime})\gamma}(Q^2) arising from the end point regions x \to 0,1 by employing the infrared-renormalon approach. The…
The production of $\eta$ and $\eta'$ mesons is studied in proton-proton and proton-lead collisions collected with the LHCb detector. Proton-proton collisions are studied at center-of-mass energies of $5.02$ and $13~{\rm TeV}$, and…
A three-body calculation of the reaction $\gamma d\to\eta np$ in the energy region from threshold up to 30 MeV above has been performed. The primary goal of this study is to assess the importance of the three-body aspects in the hadronic…
We describe production of heavy quarkonia in pA collisions within the dipole approach, assuming dominance of the perturbative color-singlet mechanism (CSM) in the $p_T$-integrated cross section. Although accounting for a nonzero heavy…
In these proceedings we present our results on the exclusive photoproduction of $J/\psi\,\eta_{c}$ pairs in the collinear factorization framework. We argue that the process might be used as a complementary channel for studying the…
The production of $\eta$ and $\eta^\prime$ mesons in photon- and hadron-induced reactions are studied in a combined analysis based on an effective Lagrangian approach in order to learn about the relevant production mechanisms and the…
I present a more refined analysis of the mass-splittings between the different heavy quarkonia states, using {\it new double ratios} of exponential moments of different two-point functions. Then, I test the validity of the $1/m$-expansion,…
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 approach to the eta'-eta complex employing chirally well-behaved quark-antiquark bound states and incorporating the non-Abelian axial anomaly of QCD through the generalization of the Witten-Veneziano relation, is extended to finite…
The $\Upsilon$ and $\eta_b$ as well as $B^*$ meson mass shifts (scalar potentials) are estimated for the first time in symmetric nuclear matter. The main interest is, whether or not the strengths of the bottomonium-nuclear matter and…
I discuss two selected examples of diffractive production of quarkonia: $p p \to p \eta' p$ and $p p \to p J/\psi p$. In the first case I consider diffractive pQCD approach and $\gamma \gamma$ fusion, in the second case the amplitude is…
In this paper we analyze the exclusive photoproduction of heavy quarkonia pairs in the collinear factorization framework. We evaluate the amplitude of the process for $J/\psi\,-\eta_{c}$ quarkonia pair in the leading order of the strong…
Incoherent photoproduction of the $\eta$-meson on the deuteron is studied for photon energies from threshold to 800 MeV. The dominant contribution, the $\gamma$N-$\eta$N amplitude, is described within an isobar model. The final state…