Low density matter probed in multifragmentation reactions W. Trautmann GSI Helmholtzzentrum, Darmstadt, Germany Workshop „Simulating the Supernova Neutrinosphere with Heavy Ion Collisions“ ECT* Trento, April 2014

ALADIN historical and personal MUSIC III ToF Lynen Lühning Müller Pochodzalla Sann Schwarz Sfienti et al. V. Serfling

multifragmentation of relativistic projectiles K. Turzó

isospin dependent multifragmentation of relativistic projectiles main result: reduced symmetry energy required for liquid drop description of fragments at freeze-out K. Turzó

the nuclear phase diagram NN2000 Strasbourg as we explore it with multifragmentation critical points from Jaqaman et al., PRC 27 (1983) 2782 Müller & Serot, PRC 52 (1995) 2072 Schnack & Feldmeier, PLB B 409 (1997) 6

astrophysical motivation dashed: adiabatic evolution, e.g., collapse (along constant entropy per baryon S/B)

HodoCT ALADiN Magnet TP-MUSIC IV TOF- Wall Target LAND ALADiN spectrometer Z resolution A resolution A. Schüttauf et al., NPA 607, 457 (1996) main topic: projectile (multi)fragmentation correlation functions with hodoscopes (160 elements) in coincidence 107 Sn 124 Sn 2m full acceptance for projectile fragments at E>400 A MeV dynamic range from Z<2 to Z=93 with good resolution

discrete states from correlations 5 Li kinematic acceptance secondary decay effects with QSM at T=5 MeV Au+Au A MeV central, 10% σ react T=5 MeV universal and limit V. Serfling et al., PRL 80 (1998) He4 g.s. vs Li5 g.s. vs Li vs Be8-1 g.s. vs Be8-2 g.s. vs Be vs HeLi Hedt 5Li 4He 8Be 5Li 150 A MeV

can fragments survive in the hot environment? Mott points determined experimentally using equilibrium assumptions for cluster emissions from 40 Ar, 64 Zn + 112,124 47AMeV Hagel et al., PRL108 (2012) thermal freeze-out 4 He, 5 Li T=5 MeV for excited state temperatures (thermal freeze-out) W.T. et al., PRC76 (2007) chemical freeze-out lines from Typel et al. (2010) ALADiN Z bound Z max T HeL i

isotopic effects in chemical freeze-out from double isotope yield ratios: T HeLi ( 3,4 He, 6,7 Li) (Albergo's formula) T BeLi ( 7,9 Be, 6,8 Li) C. Sfienti et al., PRL 102 (2009)

isotopic effects in chemical freeze-out from double isotope yield ratios: T HeLi ( 3,4 He, 6,7 Li) (Albergo's formula) T BeLi ( 7,9 Be, 6,8 Li) C. Sfienti et al., PRL 102 (2009) issue: dynamical compound stability vs. fragmentation phase space

temperatures from SMM ensemble calculations mean microcanonical temperatures experimental isotope temperatures

densities from correlations Au+Au 1 A GeV S. Fritz et al., PLB 461 (1999) without filter ρ/ρ 0 = 0.1 – 0.4 from radius of sphere and number of spectator nucleons R Au =6.7 fm R≈8 fm R≈10 fm R≈9.5 fm p+p

densities from moving source fits Coulomb energies according to the fission systematics for decaying nuclei of Z=79 and Z = 39 U. Milkau et al., PRC 44 (1991) inclusive reactions on Au

density in dynamical approaches SACA method identifies fragments at 60 fm/c and ρ/ρ 0 ≈ 0.6 QMD with simulated annealing clusterization algorithm (Aichelin, Puri et al.) figures from Vermani and Puri, EPL 85 (2009) 60 fm/c MST SACA ALADIN data

fragment modifications

HodoCT ALADiN Magnet TP-MUSIC IV TOF- Wall Target LAND ALADiN experiment S254 Z resolution A resolution C. Sfienti et al., PRL 102 (2009), R. Ogul et al., PRC 83 (2011) main result: reduced symmetry energy of fragments in the hot environment; will affect neutron capture rates in SN 107 Sn 124 Sn 2m Projectile fragmentation of neutron-rich and neutron-poor projectiles: 124 Sn, 107 Sn, 124 La (1.14 ≤ N/Z)

SMM ensemble calculations used for analysis mass variation with excitation energy taken into account; fixed to reproduce exclusive yields Z bound = ΣZ i with Z i ≥2 A.S. Botvina, N. Buyukcizmeci, R. Ogul et al. (SMM: Statistical Multifragmentation Model) and model study of sensitivities meant to reproduce participant-spectator geometry

Statistical Multifragmentation Model SMM standard modified 124 Sn 124 La exp standard main result: neutron-rich fragment yields require low symmetry energy R. Ogul et al., PRC 83 (2011)

Isoscaling: Experiment vs. SMM experiment surface alone symmetry term reduced at chemical freeze-out in multifragmentation reactions

S. Bianchin,K. Kezzar, A. Le Fèvre, J. Lühning, J. Lukasik, U. Lynen, W.F.J. Müller, H. Orth, A.N. Otte, H. Sann, C.Schwarz, C. Sfienti, W. Trautmann, J. Wiechula, M.Hellström, D. Henzlova, K. Sümmerer, H. Weick, P.Adrich, T. Aumann, H. Emling, H. Johansson,Y. Leifels, R. Palit, H. Simon, M. De Napoli, G. Imme', G.Raciti, E.Rapisarda, R. Bassini, C. Boiano, I. Iori, A. Pullia, W.G.Lynch, M. Mocko, M.B. Tsang, G. Verde, M. Wallace, C.O. Bacri, A. Lafriakh,A. Boudard, J-E. Ducret, E.LeGentil, C. Volant, T. Barczyk, J. Brzychczyk, Z. Majka, A. Wieloch, J. Cibor, B. Czech, P. Pawlowski, A. Mykulyak, B. Zwieglinski, A. Chbihi, J. Frankland and A.S. Botvina S. Bianchin, K. Kezzar, A. Le Fèvre, J. Lühning, J. Lukasik, U. Lynen, W.F.J. Müller, H. Orth, A.N. Otte, H. Sann, C.Schwarz, C. Sfienti, W. Trautmann, J. Wiechula, M.Hellström, D. Henzlova, K. Sümmerer, H. Weick, P.Adrich, T. Aumann, H. Emling, H. Johansson, Y. Leifels, R. Palit, H. Simon, M. De Napoli, G. Imme', G.Raciti, E.Rapisarda, R. Bassini, C. Boiano, I. Iori, A. Pullia, W.G.Lynch, M. Mocko, M.B. Tsang, G. Verde, M. Wallace, C.O. Bacri, A. Lafriakh, A. Boudard, J-E. Ducret, E.LeGentil, C. Volant, T. Barczyk, J. Brzychczyk, Z. Majka, A. Wieloch, J. Cibor, B. Czech, P. Pawlowski, A. Mykulyak, B. Zwieglinski, A. Chbihi, J. Frankland and A.S. Botvina

memory of earlier stages

The largest fragment as order parameter percolation describes the partitions well Kreutz et al., Nucl. Phys. A556 (1993)

classical molecular dynamics early fragment recognition and persistence X. Campi et al., Phys. Rev. C 67, (2003)

Fermi motion

Schüttauf et al., NPA 607, 457 (1996) Föhr et al., PRC 84, (2011) prop.√Z T ≈ 15 MeV momentum widths in projectile fragmentation ALADIN and FRS at GSI σ 0 = 115 MeV T ≈ 14 MeV T = 15 MeV expected for cold Au in the Goldhaber model

Odeh et al., PRL 84, 4557 (2000) with analysis following Bauer, PRC 51, 803 (1995) prop.√Z T ≈ 15 MeV kinetic temperatures in projectile fragmentation interpreted within the „hot“ Goldhaber model of Bauer Bauer‘s numerical solution for ρ/ρ 0 = 1 for ρ/ρ 0 = 0.3

control of the composition

ALADIN experiment S254 contour lines represent limiting temperatures following temperature dependent Hartree-Fock calculations using Skyrme forces N Z A= Sn, 124 La 124 Sn, 197 Au 600 A MeV "Mass and isospin effects in multifragmentation" secondary beams from 142 Nd

evaporation attractor line R.J. Charity, PRC 58, 1073 (1998)

nuclear structure and memory effects SMM ensemble calculations by A.S. Botvina, R. Ogul et al. lines SMM symbols exp 124 Sn 124 La 107 Sn ALADIN experiment S254

nuclear structure and memory effects SMM ensemble calculations by A.S. Botvina, R. Ogul et al. lines SMM symbols exp 238 U 56 Fe 124 Sn 107 Sn 124 Sn 124 La 107 Sn ALADIN experiment S254 U, Fe from FRS

SMM calculations with ensembles from ALADIN study A/Z of the initial projectiles 2.24 vs Sn Sn 124 Sn Sn data: V. Föhr et al., PRC 84, (2011) analysis: H. Imal et al., arXiv: [nucl-th] projectile fragmentation at 1 AGeV (FRS at GSI)

collaborations

present outlook on FAIR

April 2014

INDRA at GSI Systems:Au + Au 40 to 150 AMeV Xe + Sn 50 to 250 AMeV C + Au 95 to 1800 AMeV Z = 3 at 100 A MeV central γβγβ y November 1997 – April 1999

INDRA at GSI November 1997 – April 1999 Systems:Au + Au 40 to 150 AMeV Xe + Sn 50 to 250 AMeV C + Au 95 to 1800 AMeV γβγβ y Z = 3 at 100 A MeV peripheral

Invariant cross sections for Au + Au at peripheral impact parameters From the Fermi to the relativistic domain INDRA at GSI

summary of S secondary beams essential to enhance effects 2. small changes of global observables with N/Z important for isolating isospin effects 3. isotope distributions exhibit memory and structure effects 4. isoscaling obeyed with high accuracy; reduced symmetry term for hot fragments 5. N/Z dependence of nuclear caloric curve indicates phase-space driven instability rather than Coulomb instability 6. spectator neutron source with T=4 MeV, invariant with system N/Z. summary of S254