Volume 334 - The 36th Annual International Symposium on Lattice Field Theory (LATTICE2018) - Poster reception
Meson electromagnetic form factors from lattice QCD
C. Davies,* J. Koponen, P. Lepage, A. Lytle, A. Zimermmane-Santos on behalf of HPQCD Collaboration
*corresponding author
Full text: pdf
Published on: 2019 May 29
Abstract
Lattice QCD can provide a direct determination of meson electromagnetic form factors, making predictions for upcoming experiments at Jefferson Lab. The form factors are a reflection of the bound-state nature of the meson and so these calculations give information about how confinement by QCD affects meson internal structure. The region of high squared (space-like) momentum-transfer, $Q^2$, is of particular interest because perturbative QCD predictions take a simple form in that limit that depends on the meson decay constant.
We previously showed in~\cite{jonnaff} that, up to $Q^2$ of 6 $\mathrm{GeV}^2$, the form factor for a `pseudo-pion' made of strange quarks was significantly larger than the asymptotic perturbative QCD result and showed no sign of heading towards that value at higher $Q^2$. Here we give predictions for real mesons, the $K^+$ and $K^0$, in anticipation of JLAB results for the $K^+$ in the next few years. We also give results for a heavier meson, the $\eta_c$, up to $Q^2$ of 25 $\mathrm{GeV}^2$ for a comparison to perturbative QCD in a higher $Q^2$ regime.
DOI: https://doi.org/10.22323/1.334.0298
Open Access