Gravitational form-factors of the $\pi$ and $K$ mesons in QCD sum rules

Abstract

Taking into account only the quark part of the energy-momentum tensor, the gravitational form-factors of the $\pi$ and $K$ mesons are calculated within the light-cone sum rules method using the distribution amplitudes of these pseudoscalar mesons. The $Q^2$-dependence of the relevant form-factors are obtained. Moreover, the mean square mass radii of $\pi$ and $K$ mesons are calculated and we find that $\sqrt{⟨r_{\pi }^2⟩}=0.31\mathrm{fm}$ and $\sqrt{⟨r_K^2⟩}=0.24\mathrm{fm}$, respectively. We compare our results for gravitational form-factors with the existing literature results. We obtain that our results on $\sqrt{⟨r_{\pi }^2⟩}$ are in good agreement with the predictions of NJL model, AdS/QCD model, and other models as well as with the existing experimental data.

Comments: 11 pages, 4 figures