Springer LINK: The European Physical Journal C - Abstract Volume 4 Issue 2 (1998) pp 231-247

The European Physical Journal C

ISSN: 1434-6044 (printed version)
ISSN: 1434-6052 (electronic version)

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Abstract Volume 4 Issue 2 (1998) pp 231-247
DOI 10.1007/s100529800874

experimental physics:
Systematic study of low-mass electron pair production in p-Be and p-Au collisions at 450 GeV/$c$

G. Agakichiev (1) (a), M. Appenheimer (2), R. Averbeck (3), F. Ballester (4), R. Baur (5) (b), A. Brenschede (2), J. Diaz (4), A. Drees (5), U. Faschingbauer (1), J.L. Ferrero (4), P. Fischer (5), Z. Fraenkel (6), M. Franke (2), C. Fuchs (1) (c), E. Gatti (7), P. Glässel (5), T. Günzel (5), C.P. de los Heros (6), F. Hess (1), R. Holzmann (3), V. Iourevitch (8) (a), D. Irmscher (5), C. Jacob (1), W. Kühn (2), B. Lenkeit (5), H. Löhner (9), A. Marin (4), F.M. Marques (4), G. Martinez (4), V. Metag (2), M. Notheisen (2), R. Novotny (2), L.H. Olsen (5), R. Ostendorf (10), Y. Panebrattsev (1) (a), A. Pfeiffer (5), I. Ravinovich (6), P. Rehak (11), M. Sampietro (7), A. Schön (5), J. Schukraft (8), Y. Schutz (10), S. Shimansky (8) (a), A. Shor (6), R.S. Simon (3), H.J. Specht (5), V. Steiner (6), S. Tapprogge (5), G. Tel-Zur (6) (d), I. Tserruya (6), T. Ullrich (5), H. Wilschut (9), J.P. Wurm (1)

(1) Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany
(2) II. Physikalisches Institut der Universität Gießen, D-35392 Gießen, Germany
(3) GSI, D-64220 Darmstadt, Germany
(4) Instituto Fisica Corpuscular, E-46100 Burjassot Valencia, Spain
(5) Physikalisches Institut der Universität Heidelberg, D-69120 Heidelberg, Germany
(6) Weizmann Institute of Science, Rehovot 76100, Israel
(7) Politecnico di Milano, I-20133 Milano, Italy
(8) CERN, CH-1211 Geneva 23, Switzerland
(9) Kernphysisch Versneller Institut, NL-9747AA Groningen, Netherlands
(10) GANIL, F-14021 Caen, France
(11) Brookhaven National Laboratory, Upton, NY 11973, USA

Received: 2 July 1997 / Published online: 5 June 1998

Abstract. In a joint effort the CERES/NA45 and TAPS collaborations have measured low-mass electron pairs in p-Be and p-Au collisions at 450 GeV/$c$ at the CERN SPS. In the range covered up to $\approx$ 1.5 GeV/$c^2$ the mass spectra from p-Be and p-Au collisions are well explained by electron pairs from decays of neutral mesons. For p-Au our result is new. For p-Be, the simultaneously measured electron pair inclusive pair spectrum in which instrumental uncertainties are highly reduced. We confirm the earlier finding of HELIOS-1 with significantly reduced systematic uncertainties of 23% in the mass range below 450 MeV/$c^2$, and of 28% in the mass range above 750 MeV/$c^2$ at 90% confidence limit. Any unconventional source of electron pairs is limited by these error margins as the percentage fraction of the hadronic contribution.

(a) visiting from JINR, Dubna, Russia
(b) Doctoral Thesis of R. Baur, University of Heidelberg (1994)
(c) Doctoral Thesis of Ch. Fuchs, University of Heidelberg (1996)
(a) visiting from JINR, Dubna, Russia
(a) visiting from JINR, Dubna, Russia
(a) visiting from JINR, Dubna, Russia
(d) Ph.D. Thesis of G. Tel-Zur, Weizmann Institute of Science (1996)

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The European Physical Journal C

experimental physics: Systematic study of low-mass electron pair production in p-Be and p-Au collisions at 450 GeV/$c$

experimental physics:
Systematic study of low-mass electron pair production in p-Be and p-Au collisions at 450 GeV/$c$