Low density matterLow density matterprobed in multifragmentation reactionsprobed in multifragmentation reactions

W. TrautmannW. TrautmannGSI Helmholtzzentrum, Darmstadt, GermanyGSI Helmholtzzentrum, Darmstadt, Germany

Workshop „Workshop „Simulating the Supernova NeutrinosphereSimulating the Supernova Neutrinospherewith Heavy Ion Collisions“with Heavy Ion Collisions“

ECT* Trento, April 2014ECT* Trento, April 2014

ALADIN 1990-2004

historical and personal

MUSIC III

ToF

LynenLühningMüllerPochodzallaSannSchwarzSfientiet al.

V. Serfling

multifragmentation of relativistic projectiles

K. Turzó

isospin dependent multifragmentation of relativistic projectiles

main result:reduced symmetry energyrequired forliquid drop description offragments at freeze-out

K. Turzó

the nuclear phase diagram

NN2000 Strasbourg

as we explore it with multifragmentation

critical points fromJaqaman et al., PRC 27 (1983) 2782Müller & Serot, PRC 52 (1995) 2072Schnack & Feldmeier, PLB B 409 (1997) 6

astrophysical motivation

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

HodoCHodoCTT

ALADiALADiN N MagneMagnett

TP-MUSIC TP-MUSIC IVIV

TOF-TOF-WallWall

TargetTarget

LANDLAND

ALADiN spectrometer Z resolutionZ resolution

A resolutionA resolution

A. Schüttauf et al., NPA 607, 457 (1996)

main topic: projectile (multi)fragmentationcorrelation functions with hodoscopes(160 elements) in coincidence

107Sn 124Sn

2m

full acceptance for projectile fragments at E>400 A MeVdynamic range from Z<2 to Z=93 with good resolution

discrete states from correlations5Li

kinematic acceptance

secondary decay effectswith QSM at T=5 MeV

Au+Au50-200 A MeVcentral, 10% σreact

T=5 MeVuniversal and limit

V. Serfling et al., PRL 80 (1998)

He4 g.s. vs. 20.21+Li5 g.s. vs. 16.66Li6 2.19 vs. 4.31+5.65Be8-1 g.s. vs. 3.04Be8-2 g.s. vs. 17.64+Be8-3 17.64+ vs. 3.04

HeLi

Hedt

5Li4He8Be

5Li

150 A MeV

can fragments survive in the hot environment?

Mott points determined experimentallyusing equilibrium assumptions for cluster emissions from 40Ar, 64Zn + 112,124Sn @ 47AMeVHagel et al., PRL108 (2012)

thermal freeze-out 4He, 5Li

T=5 MeV for excited statetemperatures (thermal freeze-out)W.T. et al., PRC76 (2007)

chemical freeze-outlines from Typel et al. (2010)

ALADiN

Zbound

Zm

ax

THeLi

Au+Au@1000

isotopic effects in chemical freeze-out

from double isotope yield ratios: THeLi (3,4He,6,7Li)(Albergo's formula) TBeLi (7,9Be,6,8Li)

C. Sfienti et al., PRL 102 (2009)

isotopic effects in chemical freeze-out

from double isotope yield ratios: THeLi (3,4He,6,7Li)(Albergo's formula) TBeLi (7,9Be,6,8Li)

C. Sfienti et al., PRL 102 (2009)

issue:dynamical compound stabilityvs. 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/ρ0 = 0.1 – 0.4

from radius of sphere andnumber of spectator nucleons

RAu=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/ρ0 ≈ 0.6

QMD with simulated annealing clusterization algorithm (Aichelin, Puri et al.)

figures from Vermani and Puri, EPL 85 (2009)60 fm/c

MSTSACA

ALADIN data

fragment modificationsfragment modifications

HodoCHodoCTT

ALADiALADiN N MagneMagnett

TP-MUSIC TP-MUSIC IVIV

TOF-TOF-WallWall

TargetTarget

LANDLAND

ALADiN experiment S254 Z resolutionZ resolution

A resolutionA resolution

C. Sfienti et al., PRL 102 (2009), R. Ogul et al., PRC 83 (2011)

main result: reduced symmetry energyof fragments in the hot environment;will affect neutron capture rates in SN

107Sn 124Sn

2m

Projectile fragmentation ofneutron-rich and neutron-poorprojectiles: 124Sn, 107Sn, 124La (1.14 ≤ N/Z)

SMM ensemble calculationsused for analysis

mass variation with excitationenergy taken into account;fixed to reproduce exclusive yields

Zbound = ΣZi with Zi≥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 ModelSMM

standard modified

124Sn

124La

exp

exp

standard

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

2514 8

4

S. Bianchin,S. Bianchin, K. Kezzar, A. Le Fèvre, J. Lühning, J. K. Kezzar, A. Le Fèvre, J. Lühning, J. Lukasik, U. Lynen, W.F.J. Müller, H. Orth, A.N. Lukasik, U. Lynen, W.F.J. Müller, H. Orth, A.N.

Otte, H. Sann, C.Schwarz, C. Sfienti, W. Otte, H. Sann, C.Schwarz, C. Sfienti, W. Trautmann, J. Wiechula, M.Hellström, D. Henzlova, Trautmann, J. Wiechula, M.Hellström, D. Henzlova, K. Sümmerer, H. Weick, P.Adrich, T. Aumann, H. K. Sümmerer, H. Weick, P.Adrich, T. Aumann, H.

Emling, H. Johansson,Emling, H. Johansson, Y. Leifels, R. Palit, H. Simon, Y. Leifels, R. Palit, H. Simon, M. De Napoli, G. Imme', G.Raciti, E.Rapisarda, R. M. De Napoli, G. Imme', G.Raciti, E.Rapisarda, R. Bassini, C. Boiano, I. Iori, A. Pullia,Bassini, C. Boiano, I. Iori, A. Pullia, W.G.Lynch, M. W.G.Lynch, M.

Mocko, M.B. Tsang, G. Verde, M. Wallace, C.O. Mocko, M.B. Tsang, G. Verde, M. Wallace, C.O. Bacri, A. Lafriakh,Bacri, A. Lafriakh, A. Boudard, J-E. Ducret, A. Boudard, J-E. Ducret,

E.LeGentil, C. Volant, T. Barczyk, J. Brzychczyk, Z. E.LeGentil, C. Volant, T. Barczyk, J. Brzychczyk, Z. Majka, A. Wieloch, J. Cibor, B. Czech, P. Pawlowski, Majka, A. Wieloch, J. Cibor, B. Czech, P. Pawlowski, A. Mykulyak, B. Zwieglinski, A. Chbihi, J. Frankland A. Mykulyak, B. Zwieglinski, A. Chbihi, J. Frankland

and A.S. Botvinaand A.S. Botvina

memory of earlier stagesmemory of earlier stages

The largest fragment as order parameter

<MIMF>

percolation describes the partitions wellKreutz et al., Nucl. Phys. A556 (1993)

classical molecular dynamics

early fragment recognition and persistence

X. Campi et al., Phys. Rev. C 67, 044610 (2003)

Fermi motionFermi motion

Schüttauf et al., NPA 607, 457 (1996) Föhr et al., PRC 84, 054605 (2011)

prop.√ZT ≈ 15 MeV

momentum widths in projectile fragmentation

ALADIN and FRS at GSI

σ0 = 115 MeVT ≈ 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.√ZT ≈ 15 MeV

kinetic temperatures in projectile fragmentation

interpreted within the „hot“ Goldhaber model of Bauer

Bauer‘s numerical solution for ρ/ρ0 = 1for ρ/ρ0 = 0.3

control of the compositioncontrol of the composition

ALADIN experiment S254

contour lines representlimiting temperatures followingtemperature dependentHartree-Fock calculationsusing Skyrme forces

N

Z

A=124

107Sn, 124La124Sn, 197Au

600 A MeV

"Mass and isospin effects in multifragmentation"secondary beams

from 142Nd

evaporation attractor line

R.J. Charity, PRC 58, 1073 (1998)

nuclear structure and memory effects

SMM ensemble calculations byA.S. Botvina,R. Ogul et al.

lines SMM

symbols exp

124Sn124La107Sn

ALADIN experiment S254

nuclear structure and memory effects

SMM ensemble calculations byA.S. Botvina,R. Ogul et al.

lines SMM

symbols exp

238U

56Fe

124Sn

107Sn124Sn124La107Sn

ALADIN experiment S254

U, Fe from FRS

SMM calculations with ensembles from ALADIN studyA/Z of the initial projectiles 2.24 vs. 2.48

112Sn + 112Sn124Sn + 124Sn

data: V. Föhr et al., PRC 84, 054605 (2011)analysis: H. Imal et al., arXiv:1403.4786 [nucl-th]

projectile fragmentation at 1 AGeV (FRS at GSI)

collaborationscollaborations

present outlook on FAIR

April 2014

INDRA at GSI

Systems: Au + Au 40 to 150 AMeVXe + Sn 50 to 250 AMeV C + Au 95 to 1800 AMeV

Z = 3 at 100 A MeV central

γβ

y

November 1997 – April 1999

INDRA at GSI

November 1997 – April 1999

Systems: Au + Au 40 to 150 AMeVXe + Sn 50 to 250 AMeV C + Au 95 to 1800 AMeV

γβ

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 S254

1. 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