We report a measurement of the process γγ *→π0 with a 759fb -1 data sample recorded with the Belle detector at the KEKB asymmetric-energy e +e - collider. The pion transition form factor, F(Q2), is measured for the kinematical region 4GeV2Q240GeV2, where -Q2 is the invariant-mass squared of a virtual photon. The measured values of Q2|F(Q2)| agree well with the previous measurements below Q29GeV2 but do not exhibit the rapid growth in the higher Q2 region seen in another recent measurement, which exceeds the asymptotic QCD expectation by as much as 50%.
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|Publication status||Published - 2012 Nov 9|
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)