Power corrections to the process $\gamma\gamma^*\rightarrow \pi\pi$ in the light-cone sum rules approach

N. Kivel; L. Mankiewicz

doi:doi:10.1007/s100520000524

EPJ

Power corrections to the process $\gamma\gamma^*\rightarrow \pi\pi$
in the light-cone sum rules approach

N. Kivel^1,2 - L. Mankiewicz^3,4

¹ Institut für Theoretische Physik, Universität Regensburg, 93040 Regensburg, Germany
² Petersburg Nuclear Physics Institute, 188350, Gatchina, Russia
³ N. Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warsaw, Poland
⁴ The Andrzej Soltan Institute for Nuclear Studies Hoza 69, 00-681 Warsaw, Poland

Abstract
We applied QCD light-cone sum rules to estimate power corrections to the helicity-conserving amplitude in the process $\gamma^*\gamma\rightarrow \pi\pi$ . We found that above $Q^2 \sim 4$ GeV² power corrections are numerically small and the twist-2 part dominates.The amplitude can be reliably calculated in this region using models of $2 \pi$ distribution amplitudes as input. We found that the magnitude of the NLO corrections depends rather strongly on the normalization of the gluonic distribution amplitude.

15th European Conference on Atoms Molecules and Photons (ECAMP)
June 30 to July 4, 2025
Innsbruck, Austria

EPJ

Power corrections to the process in the light-cone sum rules approach

Conference announcements

Power corrections to the process $\gamma\gamma^*\rightarrow \pi\pi$
in the light-cone sum rules approach