Soft end-point and mass corrections to the eta' g*g* vertex function

TL;DR

This paper calculates power-suppressed corrections to the eta' g*g* vertex function using the hard-scattering approach and infrared renormalon calculus, revealing significant enhancements over standard results in the 1-25 GeV^2 range.

Contribution

It introduces Borel resummed expressions for the eta' g*g* vertex function including mass effects and quark-gluon contributions, extending previous fixed-coupling analyses.

Findings

Power-suppressed corrections significantly enhance the vertex function.

Mass effects of the eta'-meson influence the vertex function.

Corrections are substantial in the 1-25 GeV^2 Q^2 range.

Abstract

Power-suppressed corrections arising from end-point integration regions to the space-like vertex function of the massive eta'-meson virtual gluon transition eta' - g*g* are computed. Calculations are performed within the standard hard-scattering approach (HSA) and the running coupling method supplemented by the infrared renormalon calculus. Contributions to the vertex function from the quark and gluon contents of the eta' -meson are taken into account and the Borel resummed expressions for F_{eta' g*g*}(Q2,\omega ,\eta), as well as for F_{eta' g g*}}(Q^{2},\omega =\pm 1,\eta) and F_{eta' g*g*}(Q^{2},\omega =0,\eta) are obtained. It is demonstrated that the power-suppressed corrections \sim (\Lambda ^{2}/Q^{2})^{n}, in the explored range of the total gluon virtuality 1 <Q2 < 25 GeV2, considerably enhance the vertex function relative to the results found in the framework of the standard HSA with a fixed coupling. Modifications generated by the eta ' -meson mass effects are discussed.