Abstract
We have measured the inclusivep T spectra of soft photons produced at central and backward rapidities in 450 GeV/cp-Be collisions down to 1 MeV/c in transverse momentum. In the region 1<p T <20 MeV/c an excess of photons over those expected from hadronic decays is observed. This excess is comparable, within systematic errors, with estimates of direct photons produced via hadronic bremsstrahlung. An upper limit is derived on the presence of additional sources of direct photons at small transverse momentum.
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A.T. Goshaw et al.: Phys. Rev. Lett. 43 (1979) 1065
P.V. Chliapnikov et al.: Phys. Lett. 141B (1984) 276
F. Botterweck et al.: Z. Phys. C 51 (1991) 541
S. Abatzis et al.: Nucl. Phys. A 525 (1991) 487c; S. Banerjee et al.: Preprint CERN-PPE/92-218, submitted to Phys. Lett. B
U. Goerlach, HELIOS Coll.: Proc. 24th Int. Conf. on High Energy Physics, Munich, 1988, p. 1412
T. Åkesson et al.: Phys. Rev. D 36 (1987) 2615; D38 (1988) 2687
F.E. Low: Phys. Rev. 110 (1958) 974
T. Åkesson et al.: Z. Phys. C 52 (1991) 219
The BaF2 array was used also in AGS experiment E855
D. Alde et al.: Preprint CERN-EP/87-28 (unpublished)
C. Erd: Thesis, TU Wien (1991), unpublished
S. Brons: Thesis, Universität Heidelberg (1990), unpublished
T. Åkesson et al.: Phys. Lett. B 192 (1987) 463; B152 (1985) 411
K. Werner: Z. Phys. C 47 (1990) 215
J. Antos: Nucl. Instrum. Methods A 249 (1986) 241; Proc. Conf. on Hadron Structure '91, Stara Lesna, Czechoslovakia, Physics and Applications, Vol. 16, p. 281
R.M. Sternheimer: Phys. Rev. 99 (1955) 277; R.G. Glasser: Phys. Rev. D6 (1972) 1993; D8 (1973) 3223; G.I. Kopylov: Nucl. Phys. B52 (1972) 126
M. Neubert: Z. Phys. C 42 (1989) 231 and private communication; R. Rückl: Phys. Lett. 64B (1976) 9; J.D. Jackson: Classical electrodynamics, 2nd edition, p. 654. New York: Wiley 1975
J. Cobb et al.: Phys. Lett. 78B (1978) 519; E.W. Beier et al.: Phys. Rev. Lett. 37 (1976) 1114
T. Åkesson et al.: in preparation; R.J. Veenhof: Thesis, University of Amsterdam UvA (1993), unpublished
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Antos, J., Beker, H., Brons, S. et al. Soft photon production in 450 GeV/cp-Be collisions. Z. Phys. C - Particles and Fields 59, 547–553 (1993). https://doi.org/10.1007/BF01562546
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DOI: https://doi.org/10.1007/BF01562546