Measurement of γγ *→π0 transition form factor at Belle

S Uehara; Y Watanabe; H Nakazawa; I Adachi; H Aihara; DM Asner; T Aushev; AM Bakich; K Belous; V Bhardwaj; B Bhuyan; M Bischofberger; A Bondar; G Bonvicini; A Bozek; M Bračko; TE Browder; MC Chang; A Chen; P Chen; BG Cheon; K Chilikin; IS Cho; K Cho; Y Choi; J Dalseno; Z Doleal; Z Drásal; S Eidelman; D Epifanov; JE Fast; M Feindt; V Gaur; N Gabyshev; YM Goh; B Golob; J Haba; K Hayasaka; H Hayashii; Y Horii; Y Hoshi; WS Hou; HJ Hyun; T Iijima; A Ishikawa; R Itoh; M Iwabuchi; Y Iwasaki; T Iwashita; T Julius; JH Kang; T Kawasaki; C Kiesling; HJ Kim; HO Kim; JB Kim; JH Kim; KT Kim; MJ Kim; YJ Kim; BR Ko; S Koblitz; P Kody; S Korpar; RT Kouzes; P Krian; P Krokovny; A Kuzmin; YJ Kwon; JS Lange; SH Lee; J Li; Y Li; J Libby; CL Lim; C Liu; Y Liu; ZQ Liu; D Liventsev; R Louvot; D Matvienko; K Miyabayashi; H Miyata; Y Miyazaki; GB Mohanty; A Moll; T Mori; N Muramatsu; Y Nagasaka; E Nakano; M Nakao; Z Natkaniec; S Nishida; K Nishimura; O Nitoh; S Ogawa; T Ohshima; S Okuno; SL Olsen; Y Onuki

Journal article

Measurement of γγ *→π0 transition form factor at Belle

S Uehara, Y Watanabe, H Nakazawa, I Adachi, H Aihara, DM Asner, T Aushev, AM Bakich, K Belous, V Bhardwaj, B Bhuyan, M Bischofberger, A Bondar, G Bonvicini, A Bozek, M Bračko, TE Browder, MC Chang, A Chen, P Chen Show all

Physical Review D Particles Fields Gravitation and Cosmology | Published : 2012

DOI: 10.1103/PhysRevD.86.092007

Abstract

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%. © 2012 American Physical Society.