Probing partonic structure in γ γ → ππ near threshold

被引:224
作者
Diehl, M [1 ]
Gousset, T
Pire, B
Teryaev, O
机构
[1] CEA Saclay, SPhN, DAPNIA, F-91191 Gif Sur Yvette, France
[2] SUBATECH, F-44307 Nantes, France
[3] Ecole Polytech, CPhT, F-91128 Palaiseau, France
[4] Joint Inst Nucl Res, Bogoliubov Lab Theoret Phys, Dubna 141980, Moscow Region, Russia
关键词
D O I
10.1103/PhysRevLett.81.1782
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
Hadron pair production gamma gamma --> h (h) over bar in the region where the c.m. energy is much smaller than the photon virtuality can be described in a factorized form, as the convolution of a partonic handbag diagram and generalized distribution amplitudes which are new nonperturbative functions describing the exclusive fragmentation of a quark-antiquark pair into two hadrons. Scaling behavior and a selection rule on photon helicity an signatures of this mechanism. The case where h is a pion is emphasized.
引用
收藏
页码:1782 / 1785
页数:4
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