https://doi.org/10.1140/epja/i2004-10075-y
Two-proton small-angle correlations in central heavy-ion collisions: A beam-energy- and system-size-dependent study
1
Institute for Nuclear Physics and Engineering, Bucharest, Romania
2
Central Research Institute for Physics, Budapest, Hungary
3
Laboratoire de Physique Corpusculaire, IN2P3/CNRS and Université Blaise Pascal, Clermont-Ferrand, France
4
Gesellschaft für Schwerionenforschung, Darmstadt, Germany
5
IKH, Forschungszentrum Rossendorf, PF 510119, D-01314, Dresden, Germany
6
Physikalisches Institut der Universität Heidelberg, Heidelberg, Germany
7
Institute for Theoretical and Experimental Physics, Moscow, Russia
8
Kurchatov Institute for Atomic Energy, Moscow, Russia
9
Korea University, Seoul, Korea
10
Institut de Recherches Subatomiques, IN2P3-CNRS/ULP, Strasbourg, France
11
Institute of Experimental Physics, Warsaw University, Warsaw, Poland
12
Rudjer Bosković Institute Zagreb, Zagreb, Croatia
* e-mail: kotte@fz-rossendorf.de
Received:
17
May
2004
Accepted:
13
September
2004
Published online:
19
November
2004
Small-angle correlations of pairs of protons emitted in central collisions of Ca + Ca, Ru + Ru and Au + Au at beam energies from 400 to 1500MeV per nucleon are investigated with the FOPI detector system at SIS/GSI Darmstadt. Dependences on system size and beam energy are presented which extend the experimental data basis of pp correlations in the SIS energy range substantially. The size of the proton-emitting source is estimated by comparing the experimental data with the output of a final-state interaction model which utilizes either static Gaussian sources or the one-body phase-space distribution of protons provided by the BUU transport approach. The trends in the experimental data, i.e. system size and beam energy dependences, are well reproduced by this hybrid model. However, the pp correlation function is found rather insensitive to the stiffness of the equation of state entering the transport model calculations.
PACS: 25.70.Pq Multifragment emission and correlations – / 25.75.Gz Particle correlations –
© Società Italiana di Fisica and Springer-Verlag, 2005