Pion Production in the <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi mathvariant="normal">Ar</mi></mrow><mprescripts></mprescripts><mrow></mrow><mrow><mn>40</mn></mrow><mrow></mrow><mrow></mrow></mmultiscripts></mrow></math></span>+<span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi mathvariant="normal">Ca</mi></mrow><mprescripts></mprescripts><mrow></mrow><mrow><mn>40</mn></mrow><mrow></mrow><mrow></mrow></mmultiscripts></mrow></math></span> Reaction at 1.05 GeV/Nucleon

K. L. Wolf; H. H. Gutbrod; W. G. Meyer; A. M. Poskanzer; A. Sandoval; R. Stock; J. Gosset; C. H. King; G. King; Nguyen Van Sen; G. D. Westfall

doi:10.1103/PhysRevLett.42.1448

Pion Production in the ${}^{40}{Ar}$ + ${}^{40}{Ca}$ Reaction at 1.05 GeV/Nucleon

K. L. Wolf, H. H. Gutbrod, W. G. Meyer, A. M. Poskanzer, A. Sandoval, R. Stock, J. Gosset, C. H. King, G. King, Nguyen Van Sen, and G. D. Westfall

Phys. Rev. Lett. 42, 1448 – Published 28 May 1979

Abstract

Pion-production cross sections have been measured for the reaction ${}^{40}{Ar} + {}^{40}{Ca} \to π^{+} + X$ at a laboratory energy of 1.05 GeV/nucleon. A maximum in the $π^{+}$ cross section occurs at mid-rapidity, which is anomalous relative to $p + p$ and $p$ +nucleus reactions and compared to many other heavy-ion reactions. Calculations based on cascade and thermal models fail to fit the data.

Received 20 February 1979

DOI:https://doi.org/10.1103/PhysRevLett.42.1448

Authors & Affiliations

K. L. Wolf^*, H. H. Gutbrod, W. G. Meyer, A. M. Poskanzer, A. Sandoval, R. Stock, J. Gosset^†, C. H. King, G. King, Nguyen Van Sen^‡, and G. D. Westfall

Lawrence Berkeley Laboratory, Berkeley, California 94720, Gesellschaft für Schwerionenforschung, Darmstadt, West Germany, and Fachbereich Physik, Universität Marburg, Marburg, West Germany

^*Present address: Argonne National Laboratory, Argonne, Ill. 60439.
^†Present address: Department de Physique Nucléaire à Moyen Energie, Centre d'Etudes Nucléaires de Saclay, 91190 Gif-sur-Yvette, France.
^‡Present address: Institute for Nuclear Studies, 38044 Grenoble, France.