ar X iv : h ep - p h / 97 08 34 5 v 1 1 3 A ug 1 99 7 SLAC - PUB - 7604 July 1997 Exclusive Photon - Photon Processes ∗

نویسنده

  • S. J. Brodsky
چکیده

Exclusive γγ → hadron pairs are among the most fundamental processes in QCD, providing a detailed examination of Compton scattering in the crossed channel. In the high momentum transfer domain (s, t, large, θ cm for t/s fixed), these processes can be computed from first principles in QCD, yielding important information on the nature of the QCD coupling α s and the form of hadron distribution amplitudes. of QCD and definitive determinations of the meson distribution amplitudes φ H (x, Q). We show that the assumption of a frozen coupling at low momentum transfers can explain the observed scaling of two-photon exclusive processes.

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تاریخ انتشار 1997