Isotopic Dependence of the Nuclear Caloric Curve

Adrich, P.; Aumann, T.; Bacri, C. O.; Barczyk, T.; Bassini, R.; Bianchin, S.; Boiano, C.; Botvina, A. S.; Boudard, A.; Brzychczyk, J.; Chbihi, A.; Cibor, J.; Czech, B.; De Napoli, M.; Ducret, J. -E.; Emling, H.; Fevre, A. Le; Frankland, J. D.; Gentil, E. Le; Hellstroem, M.; Henzlova, D.; Imme, G.; Iori, I.; Johansson, H.; Kezzar, K.; Lafriakh, A.; Leifels, Y.; Luehning, J.; Lukasik, J.; Lynch, W. G.; Lynen, U.; Majka, Z.; Mocko, M.; Mueller, W. F. J.; Mykulyak, A.; Orth, H.; Otte, A. N.; Palit, R.; Pawlowski, P.; Pullia, A.; Raciti, G.; Rapisarda, E.; Sann, H.; Schwarz, C.; Sfienti, C.; Simon, H.; Suemmerer, K.; The ALADIN2000 Collaboration; Trautmann, W.; Tsang, M. B.; Verde, G.; Volant, C.; Wallace, M.; Weick, H.; Wiechula, J.; Wieloch, A.; Zwieglinski, B.

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Isotopic Dependence of the Nuclear Caloric Curve

Abstract

The A/Z dependence of projectile fragmentation at relativistic energies has been studied with the ALADIN forward spectrometer at SIS. A stable beam of 124Sn and radioactive beams of 124La and 107Sn at 600 MeV per nucleon have been used in order to explore a wide range of isotopic compositions. Chemical freeze-out temperatures are found to be nearly invariant with respect to the A/Z of the produced spectator sources, consistent with predictions for expanded systems. Small Coulomb effects (\Delta T \approx 0.6 MeV) appear for residue production near the onset of multifragmentation.Comment: 11 pages, 3 figures, accepted for publ. in Phys. Rev. Let