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Measurement of the Response of the Spectators to the Participants Blast. M. V. Ricciardi a , T. Enqvist a,[1] , J. Pereira b , J. Benlliure b , M. Bernas c , E. Casarejos b , V. Henzl a , A. Kelić a , J. Taieb c,[2] , K.-H. Schmidt a a GSI, Planckstr. 1, 64291, Darmstadt, Germany
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Measurement of the Response of the Spectators to the Participants Blast M. V. Ricciardia, T. Enqvista,[1], J. Pereirab, J. Benlliureb, M. Bernasc, E. Casarejosb, V. Henzla, A. Kelića, J. Taiebc,[2], K.-H. Schmidta aGSI, Planckstr. 1, 64291, Darmstadt, Germany bUniversity of Santiago de Compostela, 15706 Santiago de Compostela, Spain cInstitut de Physique Nucléaire, 91406 Orsay Cedex, France [1] Present address: University of Jyväskylä, 40351 Jyväskylä, Finland [2] Present address: CEA/Saclay DM2S/SERMA/LENR, 91191 Gif/Yvette CEDEX, France
Motivation BUU calculations : 124Sn +124Sn Tlab= 800 MeV/u b = 5 fm L. Shi, P. Danielewicz, R. Lacey, PRC 64 (2001) The surviving spectator is influenced by the blast of the participants Response of the spectators is ruled by the properties of the nuclear matter (=> EOS) !!!
The experiment at the Fragment Separator,GSI-Darmstadt Once mass and charge are identified (A, Z are integer numbers) the velocity is calculated from B => veryprecise evaluation!
Velocity distributions of fragmentation residues 238U+Pb (dashed line) 238U+Ti (full lines) T.Enqvist et al. NPA658(1999)47 M.V.Ricciardi et al. submitted to PRL
Mean velocities of fragmentation residues T.Enqvist et al. NPA658(1999)47 M.V.Ricciardi et al. submitted to PRL • Indications for the postulated response of the spectators to the participant blast. • Precise velocity measurement of projectile fragments is a new tool to investigate the EOS of nuclear matter
The epilogue:“What can we learn from the spectators?” Theoretical calculations:(Shi, Danielewicz, Lacey) • Change of the net momentum (NM) depends on momentum dependence of the nuclear mean field (MF) • Dependence of NM change on stiffness of EOS very small • Different reaction systems => different response