Related papers: $\eta'-g^*-g$ Transition Form Factor with Gluon Co…
The spin wave function of the f0(980)-meson is constructed under the assumption that the meson is dominantly a quark-antiquark state. This wave function is used in a calculation of the gamma* - f0 transition form factors. In the real-photon…
The $\Delta(1232) \to \gamma^\ast N$ magnetic dipole form factor ($G_M^\ast$) is described here within a new covariant model that combines the valence quark core together with the pion cloud contributions. The pion cloud term is…
The production of pseudo scalar, Eeta, Eta-prime, and vector, Omega, Rho, Phi, mesons in NN collisions at threshold-near energies is analyzed within a covariant effective meson-nucleon theory. It is shown that a good description of cross…
We present a calculation of the process B --> D eta' within a heavy-light chiral quark model. We assume that the eta' has a large gluonic component, and its coupling is described via the glue-glue-eta' effective vertex. The main…
The description of the VV'P form factors (V,V' stands for vector particles and P for a pseudoscalar meson) for different particles virtualities remains a challenge for the theory of strong interactions. While their chiral limit is well…
Employing the standard hard-scattering approach (HSA) in conjunction with the running-coupling (RC) method, the latter joined with the infrared-renormalon calculus, we compute power-suppressed corrections $\sim 1/Q^{2n}, n=1, 2,...$ to the…
The recent high-precision data for the reaction $\gamma p\to p\eta'$ at photon energies in the range 1.5--2.3 GeV obtained by the CLAS collaboration at the Jefferson Laboratory have been analyzed within an extended version of the…
The quark/gluon content of eta(1295) and eta(1440) mesons is discussed, mesons being considered as members of the first radial excitation 2^1S_0 qqbar nonet. Recent results on eta(1295) and eta(1440) two-photon widths from L3 together with…
The C2/M1 ratio of the electromagnetic N->Delta(1232) transition, which is important for determining the geometric shape of the nucleon, is shown to be related to the neutron elastic form factor ratio G_C^n/G_M^n. The proposed relation…
Gravitational form factors (GFFs), defined through the matrix elements of the energy-momentum tensor, provide critical insights into the internal structure of nucleons and nuclei. In particular, their Fourier transforms -- evaluated in the…
The form factors of the $\pi \rho$ and $\pi \omega$ radiative transitions are evaluated within a light-front constituent quark model, using for the first time the eigenfunctions of a light-front mass operator reproducing the meson mass…
Using the CLEO-II detector, we have studied the exclusive two-photon production of the light pseudoscalar mesons in a single tagged mode. We report on a preliminary measurement of the $\pi^0$, $\eta$ and $\eta^{\prime}$ electromagnetic form…
Similar to other heavy flavor mesons, the weak decays of $D^*_{(s)}$ mesons can provide a platform to verify the standard model, explore new physics, and understand the mechanisms of weak interactions. At present, the theoretical and…
Intriguing B --> K eta' decays provide a unique opportunity to study a joining of two-gluon configurations arising from the penguin b --> sG and b --> sGG transitions, with those inherent to the eta' particle. We employ the heavy-light…
We report on the observation of the eta_c^' (2 ^1S_0), the radial excitation of eta_c (1 ^1S_0) ground state of charmonium, in the two-photon fusion reaction gamma gamma to eta_c^' to K_S^0 K^{\pm} pi^{\mp} in 13.4 fb^{-1} of CLEO II/II.V…
We study the reaction e+e- --> e+e- eta_c, eta_c --> K_S K+- pi-+ and obtain eta_c mass and width values 2982.2+-0.4+-1.6 MeV/c^2 and 31.7+-1.2+-0.8 MeV, respectively. We find Gamma(eta_c --> gamma gamma)B(eta_c --> K anti-K…
We analyze the existing data on electroproduction of eta mesons in the region of W~1.5GeV, and extract an electrostrong form factor for the N*(1535) electroexcitation and decay into the eta-N channel, which is found to be relatively…
Combining three mechanisms, we reanalysis processes of $B \to \eta^{\prime} K(K^*),\eta K(K^*)$ and calculate their branching ratios. The results are compared with other mechanisms in the literature. The striking feature of the gluon fusion…
We study the transition form factor of $\pi^0\to\gamma^* \gamma$ as a function of the momentum transfer $Q^2$ within the light-front quark model (LFQM). We compare our result with the experimental data by BaBar as well as other calculations…
In this paper we study the $\eta'$ in $N_f=2+1+1$ lattice QCD simulations at finite temperature. Results are obtained from the analysis of the gluonic defined topological charge density correlator after gradient flow. Our results indicate…