Hard-photon and neutral-meson production in heavy-ion collisions

This lecture is structured in the following way. After a brief description of experimental techniques in sect. 2 the competition between proton-neutron bremsstrahlung and thermal photon emission at low bombarding energies (<20 MeV/u) are discussed in sect. 3. The impact parameter dependence of the hard-photon yield and a systematics of hard-photon emission in heavy-ion collisions are presented in sect. 4 and 5. Section 6 is devoted to a systematics on neutral-meson production in heavy-ion collisions. A brief account of theoretical model calculations and illustrative examples for a comparison with experimental results are presented in sect. 7. Finally, prospects of future experiments at higher bombarding energies (>200 MeV/u) are outlined which focus on studies of compressed nuclear matter via photon and meson production in relativistic heavy-ion reactions. (orig./HSI)