The asymptotics of the transition form factor γγ* -> pi^o and QCD sum rules
| dc.creator | Radyushkin, A. V. | |
| dc.creator | Ruskov, R. | |
| dc.date | 1997-06-26 | |
| dc.date.accessioned | 2026-07-07T04:02:00Z | |
| dc.date.available | 2026-07-07T04:02:00Z | |
| dc.description | In this paper we present the result of a direct QCD sum rule calculation of the transition form factor γγ* -> pi^o in the region of moderately large invariant momentum Q^2 > 1GeV^2 of the virtual photon. In contrast to pQCD, we make no assumptions about the shape of the pion distribution amplitude ϕ_π(x). Our results agree with the Brodsky-Lepage proposal that the Q^2-dependence of this form factor is given by an interpolation between its Q^2=0 value fixed by the axial anomaly and 1/Q^2 pQCD behaviour for large Q^2, with normalization corresponding to the asymptotic form ϕ_π^as (x)=6 f_πx (1-x) of the pion distribution amplitude. Our prediction for the from factor $F_{γ^*γ^*π^\circ}(q_1^2 = 0,q_2^2 = -Q^2)$ is in good agreement with new CLEO data. | |
| dc.description | 6 pages, LaTeX (sprocl.sty, 1 eps figure incl.), Talk presented by R. Ruskov at the International Conference on the Structure and the Interactions of the Photon, Egmond aan Zee, The Netherlands, 10-15 May, 1997; to be published in the proceedings | |
| dc.identifier | https://arxiv.org/abs/hep-ph/9706518 | |
| dc.identifier | http://arxiv.org/abs/hep-ph/9706518 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/47059 | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | The asymptotics of the transition form factor γγ* -> pi^o and QCD sum rules | |
| dc.type | text |