1. Measurement of the total hadronic cross section in taggedγγreactions
- Author
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N. A. Nicol, Orin I. Dahl, F. R. Rouse, J. G. Layter, J. J. Eastman, R. Belcinski, S. Toutounchi, G. Masek, Robert W. Kenney, D. H. Stork, C. Ho, M. K. Sullivan, L. G. Mathis, C. Zeitlin, H. Aihara, Philippe Eberhard, A. R. Clark, S. J. Maxfield, R. E. Avery, M. G. Strauss, S. K. Park, T. Kamae, E. M. Wang, T. K. Edberg, S. C. Loken, William A. Wenzel, Z. R. Wolf, W. Vernon, M. Pripstein, Willem G. J. Langeveld, J. S. Steinman, K. A. Derby, M. T. Ronan, M. L. Stevenson, Werner Hofmann, P. J. Oddone, W. T. Lin, W. Wagner, D. A. Bauer, R. R. McNeil, George P Yost, Y. T. Oyang, D. E. Pellett, Tadayuki Takahashi, G. Godfrey, J. Lys, A. Fridman, M. Daoudi, R. R. Kofler, H. Yamamoto, B. D. Magnuson, H. Oh, D. R. Nygren, J. C. Sens, H. H. Bingham, Gilbert Shapiro, D. O. Caldwell, S. Khacheryan, S. J. Yellin, J. R. Smith, S. B. Chun, R. W. Stephens, G. Lynch, F. C. Erné, A. M. Eisner, Ronald R. Ross, K. H. Fairfield, H. P. Paar, G. J. VanDalen, J. M. Hauptman, C. D. Buchanan, K. A. Schwitkis, H. Marsiske, A. P.T. Palounek, G. D. Cowan, A. Bay, D. J. Lambert, G. Zapalac, Margaret Alston-Garnjost, R. van Tyen, A. R. Barker, H. Y. Chao, D. A. Crane, F.L. Linde, R. J. Madaras, B. C. Shen, A. Lu, Elliott D. Bloom, Y. X. Wang, and E. S. Miller
- Subjects
Physics ,Quantum chromodynamics ,Nuclear physics ,Particle physics ,Photon ,Scattering ,Hadron ,Elementary particle ,Parton ,Fermion ,Energy (signal processing) - Abstract
We present a measurement of the total cross section for {gamma}{gamma}{r arrow}hadrons, with one photon quasireal and the other a spacelike photon of mass squared {minus}{ital Q}{sup 2}. Results are presented as a function of {ital Q}{sup 2} and the {gamma}{gamma} center-of-mass energy {ital W}, with the {ital Q}{sup 2} range extending from 0.2 to 60 GeV{sup 2}, and {ital W} in the range from 2 to 10 GeV. The data were taken with the TPC/Two-Gamma facility at the SLAC {ital e}{sup +}{ital e}{sup {minus}} storage ring PEP, which was operated at a beam energy of 14.5 GeV. The cross section exhibits a gentle falloff with increasing {ital W}. Its {ital Q}{sup 2} dependence is shown to be well described by an incoherent sum of vector-meson and pointlike scattering over most of the observed {ital W} range. Agreement at high {ital Q}{sup 2} is improved if a minimum-{ital p}{sub {ital T}} cutoff (motivated by QCD) is imposed on the pointlike contribution.
- Published
- 1990