Charmonium spectroscopy motivated by general features of pNRQCD

Abstract

Mass spectrum of charmonium is computed in the framework of potential non-relativistic quantum chromodynamics. \textit{O}$(1/m)$ and \textit{O}$(1/m^2)$ relativistic corrections to the Cornell potential and spin-dependent potential have been added, and is solved numerically. New experimentally observed and modified positive and negative parity states like $\mathbf{\psi }(4230)$, $\mathbf{\psi }(4260)$, $\mathbf{\psi }(4360)$, $\mathbf{\psi }(4390)$, $\mathbf{\psi }(4660)$, ${\mathbf{\chi }}_{c1}(4140)$ and ${\mathbf{\chi }}_{c1}(4274)$ near open-flavor threshold have also been studied. We explain them as admixtures of S-D wave states and P-wave states. Apart from these states, some other states like $X(3915)$, ${\mathbf{\chi }}_{c1}(3872)$, $\mathbf{\psi }(3770)$ and $\mathbf{\psi }(4160)$ have been identified as $2^3{P}_0$, $2^3{P}_1$, $1^3{D}_1$ and $2^3{D}_1$ states. Subsequently, the electromagnetic transition widths and $\gamma \gamma$, $e^{+}{e}^{-}$, light hadron and $\gamma \gamma \gamma$ decay widths of several states are calculated at various leading orders. All the calculated results are compared with experimental and results from various theoretical models.

Comments: 17 pages, 4 figures (Suggestions and comments are invited)