Abstract
We present data on photon production in non single-diffractivep \(\bar p\)-collisions at c.m. energies of 200 and 900 GeV. Besides the general properties of photon production, i.e. pseudorapidity distribution and average multiplicity, we also investigate photon-charged two-particle pseudorapidity and multiplicity correlations. We find for the average number of photons in non single-diffractivep \(\bar p\)-collisions 22.2±1.4±2.0 at 200 GeV and 41.4±2.1±3.5 at 900 GeV, where the first error is statistical and the second systematic. The analysis of photon-charged particle multiplicity correlations reveals strong positive correlations between the average number of photons and the number of simultaneously produced charged particles, as expected from FNAL and ISR studies and from our result at 546 GeV. We obtain for the correlation slope 0.95±0.08±0.11 at 200 GeV and 1.09±0.09±0.13 at 900 GeV (first error is statistical and the second systematic). The investigation of photon-charged two-particle pseudorapidity correlations shows that these correlations are of short range and compatible with the observed charged two-particle pseudorapidity correlations. These correlations and the results for the average number of photons as a function of the produced number of charged particles favour the conclusion that photon sources other than π0 s contribute significantly to the observed photon yield in non single-diffractivep \(\bar p\)-collisions. For example, if all photons are assumed to come from π0 s and η mesons, a η/π0 ratio of about 20% is inferred.
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UA 5 Coll. G.J. Alner et al.: Phys. Rep. 154 (1987) 247
UA 5 Coll. G.J. Alner et al.: Z. Phys. C — Particles and Fields 32 (1986) 153
UA 5 Coll. G.J. Alner et al.: Z. Phys. C — Particles and Fields 33 (1986) 1
UA 5 Coll. R.E. Ansorge et al.: Z. Phys. C — Particles and Fields 37 (1988) 191
C.M.G. Lattes et al.: Phys. Rep. 65 (1980) 151; M. Tamada: Nouvo Cimento 41 B (1977) 245; A.S. Borisov et al.: Phys. Lett. 190 B (1987) 226
UA 5 Coll. G.J. Alner et al.: Phys. Lett. 180 B (1986) 415
B. Eckart: Ph. D. Thesis, University of Bonn, BONN IR-88-21 (1988)
UA 5 Coll. K. Alpgård et al.: Phys. Lett. 115 B (1982) 71
Th. Müller: Ph. D. Thesis, University of Bonn, BONN IR-83-21 (1983)
L. Burow: Ph. D. Thesis, University of Bonn, BONN IR-87-25 (1987)
R.S. De Wolf: Ph. D. Thesis, University of Cambridge (1986)
W. Pelzer: Diploma Thesis, University of Bonn, BONN IR-85-39 (1985)
C.J.S. Webber: Ph. D. Thesis, University of Cambridge (1988)
B. Holl: Ph. D. Thesis, University of Bonn, BONN IR-88-62 (1988)
UA 5 Coll. G.J. Alner et al.: Nucl. Phys. B 291 (1987) 445
H. Albrecht: Ph. D. Thesis, University of Heidelberg (1978)
M. Boratov et al.: Nucl. Phys. B 111 (1976) 529
J.J. Dumont et al.: Z. Phys. C — Particles and Fields 13 (1982) 1
M. Alston-Garnjost et al.: Phys. Rev. Lett. 35 (1975) 142
J.W. Chapman et al.: Phys. Lett. B 47 (1973) 465
K. Jaeger et al.: Phys. Rev. D 11 (1975) 2405
T. Kafka et al.: Phys. Rev. D 19 (1975) 76
F.T. Dao et al.: Phys. Rev. Lett. 30 (1973) 1151
A. Sheng et al.: Phys. Rev. D 11 (1975) 1733
R.D. Kass et al.: Phys. Rev. D 20 (1979) 605
N. Arata: Rio de Janeiro preprint CBPF-UF002/83 (1983); N. Arata: Nucl. Phys. B 211 (1983) 189
Y. Takahashi: private communication
UA 5 Coll. G.J. Alner et al.: Phys. Lett. 167B (1986) 476; UA 5 Coll. R.E. Ansorge et al.: Charged particle multiplicity distribution at 200 GeV, and 900 GeV c.m. energy. Z. Phys. C — Particles and Fields to appear (1989)
V.V. Ammosov et al.: Phys. Lett. 42B (1972) 519
W.M. Morse et al.: Phys. Rev. D 15 (1977) 66
C. Bromberg et al.: Phys. Rev. Lett. 31 (1973) 1563
S. Barish et al.: Phys. Rev. D 9 (1974) 2689
A. Firestone et al.: Phys. Rev. D 10 (1974) 2080
M. Aguilar-Benitez et al.: Review of particle properties. Phys. Lett. 170 B (1986)
G. Jansco et al.: Nucl. Phys. B 124 (1977) 1
E.L. Berger et al.: Phys. Rev. D 7 (1973) 1412
D. Drijard, S. Pokorsky: Phys. Lett. 43 B (1973) 509
D. Horn, A. Schwimmer: Nucl. Phys. B 52 (1973) 627
P. Grassberger, H.I. Miettinen: Nucl. Phys. B 82 (1974) 26; P. Grassberger, H.I. Miettinen Nucl. Phys. B 89 (1975) 109
B. Åsman: Ph. D. Thesis, University of Stockholm (1986)
UA 5 Coll. G.J. Alner et al.: Phys. Lett. 160B (1985) 199
B. Holl, UA 5 internal Note: A simple cluster model for two-particle pseudorapidity correlations.
A. Breakstone et al.: Phys. Rev. D 30 (1984) 528
A. Bialas: 4th International Symposium on Multiparticle Hadrodynamics, Pavia, 1973, p. 93
S.R. Amendolia et al.: Phys. Lett. 48 B (1974) 359
H. Dibon et al.: Phys. Lett. 44 B (1975) 313
E.L. Berger: Nucl. Phys. B 85 (1975) 61
J. Benecke, J. Kühn: Nucl. Phys. B 140 (1978) 179
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UA 5 Collaboration., Ansorge, R.E., Åsman, B. et al. Photon production at c.m. energies of 200 and 900 GeV. Z. Phys. C - Particles and Fields 43, 75–89 (1989). https://doi.org/10.1007/BF02430612
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DOI: https://doi.org/10.1007/BF02430612