Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10724587 | Physics Letters B | 2006 | 10 Pages |
Abstract
We calculate the lowest order QCD amplitude, i.e. the quark exchange contribution, to the forward production amplitude of a pair of longitudinally polarized Ï mesons in the scattering of two virtual photons γâ(Q1)γâ(Q2)âÏL0ÏL0. We show that the scattering amplitude simultaneously factorizes in two quite different ways: the part with transverse photons is described by the QCD factorization formula involving the generalized distribution amplitude of two final Ï mesons, whereas the part with longitudinally polarized photons takes the QCD factorized form with the γLââÏL0 transition distribution amplitude. Perturbative expressions for these, in general, non-perturbative functions are obtained in terms of the Ï-meson distribution amplitude.
Related Topics
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Authors
B. Pire, M. Segond, L. Szymanowski, S. Wallon,