Radiative transitions in charmonium from $N_f=2$ twisted mass lattice QCD

TL;DR

This study uses $N_f=2$ twisted mass lattice QCD to analyze charmonium radiative transitions and form factors, providing results that are compared with previous lattice and experimental data.

Contribution

First lattice QCD calculation of charmonium radiative transitions using $N_f=2$ twisted mass fermions with detailed form factor analysis.

Findings

Results agree with experimental data within uncertainties

Lattice results improve understanding of charmonium structure

Comparison with quenched results highlights effects of dynamical quarks

Abstract

We present a study for charmonium radiative transitions: $J/\psi\rightarrow\eta_c\gamma$, $\chi_{c0}\rightarrow J/\Psi\gamma$ and $h_c\rightarrow\eta_c\gamma$ using $N_f=2$ twisted mass lattice QCD gauge configurations. The single-quark vector form factors for $\eta_c$ and $\chi_{c0}$ are also determined. The simulation is performed at a lattice spacing of $a= 0.06666$ fm and the lattice size is $32^3\times 64$. After extrapolation of lattice data at nonzero $Q^2$ to 0, we compare our results with previous quenched lattice results and the available experimental values.