Abstract
A search for massive photon pair production at\(\sqrt s = 63 GeV\) has been carried out on the data sample previously employed for the electron pair production study. Positive evidence is reported form γγ>6GeV, with a production cross-section similar to Drell-Yan electron pairs. The ratio γγ/π0π0 was measured to be ∼10−3 for ap T of each γ or γ or π0 above 3 GeV/c.
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S.M. Berman et al.: Phys. Rev.D4, 3388 (1971); K. Soh et al.: Phys. Rev.D18, 751 (1978); M. Krawegky, W. Ochs: Phys. Lett.79B, 119 (1978); S. Hemmi: Prog. Theor. Phys.63, 1073 (1980)
B.L. Combridge: CALTECH preprint CALT-68-766 (1980); C. Carimalo et al.: Phys. Lett98B, 105 (1981)
F. Paige, I. Stumer: Proc. ISABELLE Summer Study, Brookhaven, 1981 (BNL-51443, p. 479. Brookhaven Nat. Lab., Upton, LI, New York, 1981)
A.P. Contogouris et al.: Two-photon production at largep T as a new test of QCD. McGill University preprint (1981)
For the calculation of the cross-section pp→γγ+X, we have used 109-1 and the distribution functions of J.F. Owens, E. Reya: Phys. Rev.D17, 303 (1978)
J.H. Cobb et al.: Phys. Lett.72B, 273 (1977); C. Kourkoumelis et al.: Phys. Lett.91B, 475 (1980)
C. Kourkoumelis et al.: Phys. Lett.84B, 271 (1979)
J.H. Cobb et al.: Phys. Rev. Lett.40, 1420 (1978); C. Kourkoumelis et al.: Phys. Lett.85B, 147 (1979); C. Kourkoumelis et al.: Nucl. Phys.B158, 39 (1979)
C. Kourkoumelis et al.: Phys. Lett.87B, 292 (1979); M. Diakonou et al.: Phys. Lett.91B, 296 (1980); E. Anassontzis et al.: Z. Phys. C — Particles and Fields13, 277 (1982)
R.L. Ford, W.R. Nelson: The EGS code system: Computer program for the Monte Carlo simulation of electromagnetic cascade showers. SLAC-210 (1978)
For ourp T range we have measured the following ratios: 109-2, 109-3, 109-4. C. Kourkoumelis et al.: Phys. Lett.84B, 277 (1979); M. Diakonou et al.: Phys. Lett.89B, 432 (1980); In the Monte Carlo program these values were assumed to be independent ofp T
M. Diakonou et al.: Phys. Lett.91B, 301 (1980); C. Kourkoumelis et al.: Nucl. Phys.B179, 1 (1981)
The ratio and the cross-sections were not corrected for the fact that real γγ events overlapping with tracks were interpreted as dileptons. We have studied the probability of chance overlap of a track with a γ within our 10° cone. We concluded that owing to our procedure, 4.7 (2.4) γγ events could have been lost forp T>3 GeV/c (4 GeV/c)
G.J. Aubrecht et al.: Ohio State University preprint COO-1545-250 (1980); R. Baier, R. Rückl: Max-Plank Inst., Munich, preprint MPI-PAE, PTH 16/82 (1982)
M. Spitzer: DESY Report 80/43 (1980).
M. Goldberg: Northeastern University preprint NUB 2425 (1980)
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This research was supported by the US Department of Energy, under Contract No. DE-AC02-76CH00016
Work supported by the US National Science Foundation
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Kourkoumelis, C., Resvanis, L.K., Filippas, T.A. et al. Search for massive photon pair production at the CERN intersecting storage rings. Z. Phys. C - Particles and Fields 16, 101–109 (1982). https://doi.org/10.1007/BF01572259
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DOI: https://doi.org/10.1007/BF01572259