Transition formfactors γ* → γf₂ (1270) and γ* → γa₂ (1320) in the e⁺e⁻ collisions

¹ Sobolev Institute for Mathematics, 630090 Novosibirsk, Russia
² Novosibirsk State University, 630090 Novosibirsk, Russia

^* e-mail: achasov@math.nsc.ru
^** e-mail: kiselev@math.nsc.ru

Published online: 28 October 2016

Abstract

Transition form factors γ* → γf₂ (1270) and γ* → γa₂ (1320) and corresponding e⁺e⁻ → γ* → f₂γ and e⁺e⁻ → γ* → a₂γ cross sections are considered up to high energies. It is shown that the QCD asymptotics of the amplitudes of the e⁺e⁻ → γ* → f₂γ and e⁺e⁻ → γ* → a₂γ reactions can be reached only by taking into account a compensation of contributions of ρ(770), ω(782) with contributions of their radial excitations. Recent BABAR measurement of the e⁺e⁻ → f₂γ → π⁺π⁻γ cross section at 10.58 GeV gives hope for detailed investigation of the γ*(s) → f₂γ and γ*(s) → a₂γ transition form factors at high energy region. Recent Belle data on the γ*(Q²)γ → f₂ transition up to Q² = 30 GeV² are taken into account.