Charmonium spectroscopy motivated by general features of pNRQCD

TL;DR

This paper computes the charmonium mass spectrum using potential non-relativistic QCD, incorporating relativistic corrections, and explains newly observed states as mixtures of different wave states, providing detailed decay width calculations and comparisons with experiments.

Contribution

It introduces a detailed potential model with relativistic corrections to explain recent charmonium states and computes their decay properties, advancing understanding of quarkonium spectroscopy.

Findings

Identification of new states as S-D and P-wave admixtures.

Calculation of electromagnetic transition widths and decay rates.

Good agreement with experimental data and other theoretical models.

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 ${{\boldsymbol \psi}{(4230)}}$, ${{\boldsymbol \psi}{(4260)}}$, ${{\boldsymbol \psi}{(4360)}}$, ${{\boldsymbol \psi}{(4390)}}$, ${{\boldsymbol \psi}{(4660)}}$, ${{\boldsymbol \chi}_{{c1}}{(4140)}}$ and ${{\boldsymbol \chi}_{{c1}}{(4274)}}$ 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 ${{\mathit X}{(3915)}}$, ${{\boldsymbol \chi}_{{c1}}{(3872)}}$, ${{\boldsymbol \psi}{(3770)}}$ and ${{\boldsymbol \psi}{(4160)}}$ have been identified as $2^3P_0$, $2^3P_1$, $1^3D_1$ and $2^3D_1$ 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.