We perform a lattice QCD calculation of the χc0→2γ decay width using a model-independent method which does not require a momentum extrapolation of the corresponding off-shell form factors. The simulation is performed on ensembles of Nf=2 twisted mass lattice QCD gauge configurations with three different lattice spacings. After a continuum extrapolation, the decay width is obtained to be Γγγ(χc0)=3.65(83)stat(21)lat.syst(66)systkeV. Albeit this large statistical error, our result is compatible with the experimental results within 1.3σ. Potential improvements of the lattice calculation in the future are also discussed.
@article{arxiv.2111.00768,
title = {Lattice calculation of $\chi_{c0} \rightarrow 2\gamma$ decay width},
author = {Zuoheng Zou and Yu Meng and Chuan Liu},
journal= {arXiv preprint arXiv:2111.00768},
year = {2022}
}