Two-photon decay of a light scalar quark-antiquark state

Abstract

The two-photon decay of a light scalar quarkonium is evaluated in a local and a nonlocal approaches. It is shown that the two-photon decay, driven by a triangle quark-loop diagram, is smaller than 1 keV for a mass below 0.7 GeV.

Comments: Presented at the workshop SCADRON 70 "Scalar Mesons and Related Topics" February 11-16, 2008, at IST in Lisbon, Portugal. 6 pages, 2 figures