Eur. Phys. J. A (2006) 30: 47-64
https://doi.org/10.1140/epja/i2006-10107-8

Dynamics and Thermodynamics with Nuclear Degrees of Freedom

High-energy probes

Laboratori Nazionali del Sud, INFN, Via S. Sofia 62, I-95123, Catania, Italy

^* e-mail: bonasera@lns.infn.it

Received: 13 February 2006
Accepted: 26 July 2006
Published online: 12 October 2006

Abstract

We review some results on energetic particle production in heavy-ion collisions below roughly 100A·MeV, both theoretically and experimentally. We discuss the possible mechanisms of particle production, as well as the possibility to gather information on the nuclear equation of state (EOS) from data. Results on subthreshold pions, energetic photons, nucleons and light charged particles (Z ⩽ 2) are discussed and contrasted to microscopic models. Important information about the first stages of the reaction are obtained by such probes. At present, we can conclude that we have at least a qualitative understanding of the processes involved when such particles are produced. However, a quantitative determination of relevant EOS parameters is still missing. The production mechanism close to the kinematical threshold (incoherent, cooperative or statistical) is not completely elucidated either. This calls for new data using more modern detector systems and comparison to more refined microscopic models.