Related papers: Predictions for $e^+e^-\to J/\psi \eta_c$ with Lig…
Light-cone Fock-state wavefunctions encode the properties of a hadron in terms of its fundamental quark and gluon degrees of freedom. A recent experiment at Fermilab, E791, demonstrates that the color coherence and shape of light-cone…
This work aims at illustrating that, for a class of leading-twist hard exclusive reactions involving two heavy quarkonia, the light-cone approach, when equipped with the strategy of refactorization of the light-cone distribution amplitude…
One of the most challenging open problems in heavy quarkonium physics is the double charm production in $e^+e^-$ annihilation at B factories. The measured cross section of $e^+ e^- \to J/\psi + \eta_c$ is much larger than leading order (LO)…
The presented paper is devoted to theoretical analysis of charmonium mesons $\eta_c$, $J/\psi$, $\chi_{c0,1,2}$, and $h_c$ production in exclusive radiative $Z$ boson decays in the frameworks of Nonrelativistic Chromodynamic and amplitude…
Diffractive dissociation of particles can be used to study their light-cone wave functions. Results from Fermilab experiment E791 for diffractive dissociation of 500 GeV/c pi- mesons into di-jets show that the |q qbar> light-cone asymptotic…
The light-cone Hamiltonian, incorporating the nonperturbative dynamics of the $q\bar q$ system connected by the string is solved numerically. The spectrum is shown to coincide with that of the center-of-mass Hamiltonian within the accuracy…
The production cross-section of h_c, the 1P_1 charmonium state, can be predicted in Non-Relativistic QCD (NRQCD) using heavy-quark symmetry. We show that at the Large Hadron Collider a large cross-section for this resonance is predicted and…
We use NRQCD to predict the cross section for $\eta_c$ production at the Tevatron. The non-perturbative matrix elements required are obtained, using heavy-quark symmetry, from the matrix elements determined from the CDF $J/\psi$ data. Our…
This paper is devoted to the study of the processes e^+e^- \to J/\Psi \eta_c, J/\Psi \eta_c', \psi' \eta_c, \psi' \eta_c' within light cone formalism. It is shown that if one disregards the contribution of higher fock states, the twist-3…
We apply the light-cone technique to electroproduction reaction $ep\to e\pi^+n$ long considered as a means of measuring the electromagnetic form factor of the pion. We show that the interpretation of the long-standing puzzle of large…
The interaction between nucleon and charmonia ($J/\psi$ and $\eta_c$) is expected to deepen our understanding of various aspects in nonperturbative QCD ranging from the origin of nucleon mass to $J/\psi$ mass modification in nuclear medium…
This work presents the differential charmonia production cross sections in high energy p+p collisions calculated using NRQCD formalism. The NRQCD formalism, factorizes the quarkonia production cross sections in terms of short distance QCD…
We compute the O(alpha_s^2) correction to the decay rate eta_c --> gamma gamma and discuss its implications for precision quarkonium physics. We study the suitability of the ratio Gamma(J/psi --> e+e-)/Gamma(eta_c --> gamma gamma), in which…
We propose a new model to create a light meson in the heavy quarkonium transition, which is inspired by the Nambu$-$Jona-Lasinio (NJL) model. Hadronic transitions of $J^{PC}=1^{--}$ higher charmonia with the emission of an $\eta$ meson are…
We use the transverse-momentum dependence of the cross section for diffractive dissociation of high energy pions to two jets to study some non-perturbative Light-Cone wave functions of the pion. We compare the predictions for this…
We hypothesize that the correct power counting for charmonia is in the parameter Lambda_QCD/m_c, but is not based purely on dimensional analysis (as is HQET). This power counting leads to predictions which differ from those resulting from…
The photon -- induced interactions, present in $ep$, $eA$, $pp$, $pA$, $AA$ and $e^+ e^-$ collisions, are expressed within the color dipole approach in terms of the photon wave function, which describes the transition of the photon into a…
We compute the fragmentation function of a light quark into S-wave fully-charmed tetraquarks ($T_{4c}$) within the nonrelativistic QCD (NRQCD) framework, at leading order in $\alpha_{s}$ and $v$. We present results for light quark…
We show results from calculations in full lattice QCD of the mass, leptonic width and radiative decay rate to eta_c of the J/psi meson. These provide few % tests of QCD. Another (1.5%) test comes from comparison of time-moments of the…
There is serious disagreement between the predictions of Non-Relativistic Quantum Chromodynamics (NRQCD) and the data on $J/\psi$ polarisation which has persisted for almost a quarter of a century. We find that if we account for the effect…