Exclusive photon-photon processes
Exclusive gamma gamma right arrow 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, Theta 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 data and the form of hadron distribution amplitudes. Similarly, the transition form factors gamma star gamma, gamma star gamma right arrow pi(o), Eta (0), Eta`, Eta(c)... provide rigorous tests of QCD and definitive determinations of the meson distribution amplitudes Phi 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.
- Research Organization:
- Stanford Linear Accelerator Center, CA (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- AC03-76SF00515
- OSTI ID:
- 621773
- Report Number(s):
- SLAC-PUB--7604; CONF-9705136--; ON: DE97009057
- Country of Publication:
- United States
- Language:
- English
Similar Records
Exclusive two-photon processes: Tests of QCD at the amplitude level
Exclusive two-photon processes: Tests of QCD at the amplitude level