Authors

J. Breitweg, Argonne National Laboratory
M. Derrick, Argonne National Laboratory
D. Krakauer, Argonne National Laboratory
S. Magill, Argonne National Laboratory
D. Mikunas, Argonne National Laboratory
B. Musgrave, Argonne National Laboratory
J. Repond, Argonne National Laboratory
R. Stanek, Argonne National Laboratory
R. L. Talaga, Argonne National Laboratory
R. Yoshida, Argonne National Laboratory
H. Zhang, Argonne National Laboratory
Margarita C. K. Mattingly, Andrews UniversityFollow
F. Anselmo, Alma Mater Studiorum Università di Bologna
P. Antonioli, Alma Mater Studiorum Università di Bologna
G. Bari, Alma Mater Studiorum Università di Bologna
M. Basile, Alma Mater Studiorum Università di Bologna
L. Bellagamba, Alma Mater Studiorum Università di Bologna
D. Boscherini, Alma Mater Studiorum Università di Bologna
A. Bruni, Alma Mater Studiorum Università di Bologna
G. Bruni, Alma Mater Studiorum Università di Bologna
G. Cara Romeo, Alma Mater Studiorum Università di Bologna
G. Castellini, Alma Mater Studiorum Università di Bologna
L. Cifarelli, Alma Mater Studiorum Università di Bologna
F. Cindolo, Alma Mater Studiorum Università di Bologna
A. Contin, Alma Mater Studiorum Università di Bologna
M. Corradi, Alma Mater Studiorum Università di Bologna
S. De Pasquale, Alma Mater Studiorum Università di Bologna
I. Gialas, Alma Mater Studiorum Università di Bologna
P. Giusti, Alma Mater Studiorum Università di Bologna
G. Iacobucci, Alma Mater Studiorum Università di Bologna
G. Laurenti, Alma Mater Studiorum Università di Bologna

Document Type

Article

Publication Date

1-1-1997

Abstract

Diffractive dissociation of quasi-real photons at a photon-proton centre of mass energy of W ≈ 200 GeV is studied with the ZEUS detector at HERA. The process under consideration is γp → XN, where X is the diffractively dissociated photon system of mass MX and N is either a proton or a nucleonic system with mass MN < 2 GeV. The cross section for this process in the interval 3 < MX < 24 GeV relative to the total photoproduction cross section was measured to be σDpartial/σtot = 6.2 ± 0.2(stat) ± 1.4(syst)%. After extrapolating this result to the mass interval of mφ2 < MX2 < 0.05W2 and correcting it for proton dissociation, the fraction of the total cross section attributed to single diffractive photon dissociation, γp → Xp, is found to be σSD/σtot = 13.3 ± 0.5(stat) ± 3.6(syst)%. The mass spectrum of the dissociated photon system in the interval 8 < MX < 24 GeV can be described by the triple pomeron (IP IP IP) diagram with an effective pomeron intercept of αIP(0) = 1.12 ± 0.04(stat) ± 0.08(syst). The cross section for photon dissociation in the range 3 < MX < 8 GeV is significantly higher than that expected from the triple pomeron amplitude describing the region 8 < MX < 24 GeV. Assuming that this discrepancy is due to a pomeron-pomeron-reggeon (IP IP IR) term, its contribution to the diffractive cross section in the interval 3 < MX < 24 GeV is estimated to be fIP IP IR = 26 ± 3(stat) ± 12(syst)%. © Springer-Verlag 1997.

Journal Title

Zeitschrift fur Physik C-Particles and Fields

Volume

75

Issue

3

First Page

421

Last Page

435

DOI

10.1007/s002880050485

First Department

Physics

Acknowledgements

Open access article retrieved July 12, 2021 from https://link.springer.com/article/10.1007/s002880050485

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