Universal behavior of the γ⁎γ→(π0, [eta], [eta]′) transition form factors

• Verfasst von: Melikhov, Dmitri [VerfasserIn]
• Verfasst von: Stech, Berthold [VerfasserIn]
• Titel: Universal behavior of the γ⁎γ→(π0, [eta], [eta]′) transition form factors
• Verf.angabe: Dmitri Melikhov, Berthold Stech
• E-Jahr: 2012
• Jahr: 5 December 2012
• Umfang: 4 S.
• Fussnoten: Gesehen am 22.11.2018
• Titel Quelle: Enthalten in: Physics letters / B
• Ort Quelle: Amsterdam : North-Holland Publ., 1967
• Jahr Quelle: 2012
• Band/Heft Quelle: 718(2012), 2, Seite 488-491
• ISSN Quelle: 1873-2445
• DOI: doi:10.1016/j.physletb.2012.10.052
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1583973907

Abstract

The photon transition form factors of π, η and η′ are discussed in view of recent measurements. It is shown that the exact axial anomaly sum rule allows a precise comparison of all three form factors at high-Q2 independent of the different structures and distribution amplitudes of the participating pseudoscalar mesons. We conclude: (i) The πγ form factor reported by Belle is in excellent agreement with the nonstrange I=0 component of the η and η′ form factors obtained from the BaBar measurements. (ii) Within errors, the πγ form factor from Belle is compatible with the asymptotic pQCD behavior, similar to the η and η′ form factors from BaBar. Still, the best fits to the data sets of πγ, ηγ, and η′γ form factors favor a universal small logarithmic rise Q2FPγ(Q2)∼log(Q2).