2024 Impact factor 4.8
Particles and Fields
Eur. Phys. J. C 4, 249-257
DOI 10.1007/s100529800804

Neutral meson production in p-Be and p-Au collisions
at 450GeV beam energy

G. Agakichiev1 - M. Appenheimer2 - R. Averbeck3 - F. Ballester4 - R. Baur5 - A. Brenschede2 - J. Diaz4 - A. Drees5 - U. Faschingbauer1 - J.L. Ferrero4 - P. Fischer5 - Z. Fraenkel6 - M. Franke2 - Ch. Fuchs1 - E. Gatti7 - P. Glässel5 - Th. Günzel5 - C. P. de los Heros6 - F. Hess1 - R. Holzmann3 - D. Irmscher5 - C. Jacob1 - W. Kühn2 - B. Lenkeit5 - H. Löhner8 - A. Marin4 - F.M. Marques4 - G. Martinez4 - V. Metag2 - M. Notheisen2 - R. Novotny2 - L. H. Olsen5 - R. Ostendorf9 - Y. Panebrattsev1 - A. Pfeiffer5 - I. Ravinovich6 - P. Rehak10 - M. Sampietro7 - A. Schön5 - J. Schukraft11 - Y. Schutz9 - S. Shimansky11 - A. Shor6 - R.S. Simon3 - H. J. Specht5 - V. Steiner6 - S. Tapprogge5 - G. Tel-Zur6 - I. Tserruya6 - Th. Ullrich5 - H. Wilschut8 - J. P. Wurm1 - V. Yurevich7

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, Rehovot 76100, Israel
7 Politecnico di Milano, I-20133 Milano, Italy
8 Kernphysisch Versneller Institut, NL-9747AA Groningen, Netherlands
9 GANIL, F-14021 Caen, France
10 Brookhaven National Laboratory, Upton, NY 11973, USA
11 CERN, CH-1211 Geneva 23, Switzerland

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

Abstract
In a joint experiment the TAPS and CERES collaborations have studied the production of the neutral mesons $\pi^\circ,\eta$ and $\omega$ in 450GeV p-Be and p-Au collisions at the CERN SPS. The mesons were identified by their $\pi^\circ\rightarrow\gamma\gamma$,$\eta\rightarrow\gamma\gamma$, and $\omega\rightarrow\pi^\circ\gamma$decay modes. The cross sections were measured down to very low pT (>= 20MeV/c) near mid-rapidity (3.0<y<4.0). The $\eta$ and $\omega$ cross sections are smaller than expected from extrapolations of earlier data to low pT. Integrated over all pT, the ratios $\eta$/$\pi^\circ$ and $\omega$/$\pi^\circ$ are lower by about 25% compared to previously published values. The reduction may be attributed to the large number of low pT pions from decays of heavier mesons. In addition, we have studied the dependence of neutral meson production on the mass of the nuclear target and find it in good agreement with previous measurements of charged mesons.


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