Impact parameter dependence of hard photon production in intermediate energy hevy-ion collisions

Hard photon production was investigated in the system Kr-86 + (nat)Ni at 60 A MeV for a wide range of impact parameters. The parameters characteristic of hard photon emission such as source velocities, angular distributions and energy spectra were studied from peripheral to central collisions. The energy spectrum is seen to be strongly dependent on the centrality of the collision reflecting both a static and dynamic momentum distribution of the nucleons inside the collision zone

Bremsstrahlung photons as a probe of hot nuclei

Aside from the dominant production of hard photons in first-chance p-n collisions, a significant hard-photon production in a later stage of heavy-ion reactions is predicted by the BUU theory. These thermal hard photons are emitted from a nearly thermalized source and still originate from bremsstrahlung produced in individual p-n collisions. The calculations predict that the production of the thermal hard photons is strongly correlated with the incompressibility of nuclear matter. Tentative experimental evidence for their production is found in the hard-photon energy spectra measured in the systems Kr-86 + Ni-nat at 60.0A MeV, Ta-181 + Au-197 at 39.5A MeV and (208)pb + Au-197 at 29.5A MeV

Density oscillations in systems of colliding heavy ions observed via hard-photon interferometry measurements

We have analyzed hard-photon intensity correlations measured in the systems Kr-86 + Ni-nat at 60.0A MeV and Ta-181 + Au-197 at 39.5A MeV assuming that hard photons are emitted from two distinct sources in space-time. We confirm the existence of the Bose-Einstein correlation between independent hard photons and attribute the origin of the two sources to the density oscillations of nuclear matter generated in intermediate-energy heavy-ion collisions via the incomplete-fusion reaction mechanism

Hard photon intensity interferometry in heavy ion reactions

International audienceIntensity correlations between hard photons produced in heavy ion collisions have been measured for Eγ≥25 MeV in the reaction 86Kr+natNi at 60A Mev bombarding energy. The observed correlation pattern is interpreted in terms of intensity interference. A correlation length of Cσ=16±4 MeV is found and the deduced photon source extent is discussed

Hard photon as a probe to study dissipation mechanisms

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A systematic study of neutral pion squeeze-out at intermediate energies

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Evidence for stopping in heavy ion collisions from a study of hard photon source velocities

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