Probing high density EOS of neutron rich

matter in heavy ion collisions

Y. Leifels for the FOPI and ASY-EOS collaborations GSI Helmholtzzentrum für Schwerionenforschung GmbH Darmstadt

XXVII Texas Symposium on

Relativistic Astrophysics

Dallas, December 8-13, 2013

transient state non-equilibrium, dynamical system thermal pressure, temperature and creation

of particles access to properties

microscopic transport models

Heavy ion collisions are unique tool to create states of high

density in the laboratory

Y. Leifels – Texas 2013 2

IQMD C. Hartnack

Central collisions

W. Cassing et al.

A. LeFevre et al.

Equation of state of nuclear/neutron matter

Y. Leifels – Texas 2013 3

Fuchs and Wolter, EPJA 30 (2006)

nuclear-many-body theory

/)(

)(O)(E)0,(E),(E

pn

4

sym

2

asymmetry parameter

Esym

E(,

)

(

MeV

)

Demorest et al. doi:10.1038/nature09466

Mass – Radius relation of neutron stars

0

2

22 )0T,(A/E

9

Compression modulus of E(,0)

Symmetry energy

Y. Leifels – Texas 2013 4

Fuchs and Wolter, EPJA 30 (2006)

0

d

)(dE3L

sym

0

slope

parameter

L small soft

SE bending over super soft

L large hard

=1.5

=0.5

used as:

Esym

= Esympot+Esym

kin

= 22 MeV·(ρ/ρ0)γ+12 MeV·(ρ/ρ0)

2/3

Testing pressure differences – Collective flow

Y. Leifels – Texas 2013 5

Elliptic flow v2

Side flow v1

P.

Da

nie

lew

icz e

t a

l. S

cie

nce

29

8,

15

92

(2

00

2)

Elliptic flow v2

Fourier expansion of azimuthal

distribution

protons

Au+Au

Elliptic flow

~d

dN

1 + 2v1cos() + 2v2cos(2)

parameterization of shape:

Elliptic flow at intermediate energies

Y. Leifels – Texas 2013 6

Au+Au

400A MeV

1.5A GeV

W. R

eis

do

rf et a

l, Nu

cl. P

hys. A

87

6 (2

01

2) 1

1.5A GeV

2)0(

2220

)0(

2

2220n2

Yvv)Y(v

vvv

beam energy (AGeV) v

2n

sensitive to EOS over a large

energy range

protons and light clusters

-v2

-v2

A. L

eF

evre

et a

l.

200 MeV

380 MeV

Constraining Esym - Elliptic flow of isospin pairs

Y. Leifels – Texas 2013 7

Experimental approach:

vary N/Z of collision system

(radioactive beams)

look at isospin pairs as probes

n/p 3He/3H π -π + K0/K+

observables: production ratios,

differences/ratios of spectra and

flows

neutron elliptic flow larger with a

‘hard’ density dependence of SE

→ investigate v2,n/v2,p or (v2,n-v2,p)

UrQMD: Qingfeng Li et al. / Y. Leifels

Data. W. Reisdorf et al.

-v2

-v2

Neutron/hydrogen elliptic flow in Au+Au collisions

Y. Leifels – Texas 2013 8

neutron squeeze-out in Au+Au collisions:

Y. Leifels et al., PRL 71, 963 (1993)

LAND 1 LAND 2

Forward Wall for

centrality and

reaction-plane

orientation

SB: shadow bar

for background

measurement

Large Area

Neutron Detector

acceptance:

in pt vs rapidity

Neutron/hydrogen elliptic flow

Y. Leifels – Texas 2013 9

Conclusion out of all available data:

n/p and n/H

by varying input parameters to the

model:

elastic NN cross sections

L = 85±40 MeV

intermediate

Au+Au

400A MeV

SE used in UrQMD model calculations P. Russotto et al. PLB 267 (2010)

P. Russotto et al., PLB 267 (2010)

v2

Neutron/hydrogen elliptic flow

Y. Leifels – Texas 2013 10

400A MeV

Towards model independence

Tested stability of results:

soft vs. hard 190<K<280 MeV

density dependence of sNN,elastic

asymmetry dependence of sNN,elastic

optical potential

momentum dependence of isovector

potential

Cozma et al. (Tübingen-QMD) :

L = 106±46 MeV

Russotto et al. (UrQMD):

L = 85±40 MeV

ruling out particular hard or soft Esym

statistics unsatisfactory

other observables?

M.D. Cozma et al., arXiv:1305.5417

P. Russotto et al., PLB 267 (2010)

Cozma et al.

Russotto et al.

The ASY-EOS experiment at GSI

Y. Leifels – SFAIR 2013 11 11

LAND CHIMERA

studied reactions: 197Au + 197Au @ 400 A MeV 96Ru + 96Ru @ 400 A MeV 96Zr + 96Zr @ 400 A MeV

CHIMERA, ALADIN Tof-wall,

μ-ball, for impact parameter

orientation and modulus

Testing density differences - The π-/π+ ratio

Y. Leifels – Texas 2013 12

Data described by various models with

stiff (or soft) density dependences of

the symmetry energy

Ferini et al. RMF stiffer for ratio up

Xiao et al. IBUU softer “

Feng & Jin ImIQMD stiffer “

Xie et al. ImIBL softer “

Data: W. Reisdorf et al., NPA 781 (2007)

Calculations: Z. Xiao et al, Phys. Rev. Lett. 102, 062502 (2009)

Au + Au central

Summary and conclusions

Y. Leifels – Texas 2013 13

At ~ (2-3)ρ0 , Ebeam=0.2 – 2 AGeV

multitude of experimental data help to

constrain the various input parameters to the

microscopic transport models

EOS of symmetric matter, in-medium

cross sections...

data support a soft Skyrme type EOS

P. Danielewicz et al., Science 298, 1592 (2002)

Symmetry energy at supra-saturation densities

very few data points at supra saturation densities

elliptic flow data

ratios or differences reduces influence of uncertainties in model

parameters

available data consistent with L~100+/- 45 MeV – new results soon

slightly harder than experiments at lower densities/astrophysical

observations

promising pion observables, but no consistent description

more data WITH radioactive beam will be available soon

Texas 2013 – Yvonne Leifels

New projects at radioactive beam facilities

RAON

SFAIR 2013 – Yvonne Leifels

The FOPI collaboration

A. Andronic, R. Averbeck, Z. Basrak, N. Bastid, M.L. Benabderramahne, M. Berger, P. Bühler,

R. Caplar, M. Cargnelli, M. Ciobanu, P. Crochet, I. Deppner, P. Dupieux, M. Dzelalija, L. Fabbietti, J. Frühauf,

F. Fu, P. Gasik, O. Hartmann, N. Herrmann, K.D. Hildenbrand, B. Hong, T.I. Kang, J. Keskemeti, Y.J. Kim, M.

Kis, M. Kirejczyk, R. Münzer, P. Koczon, M. Korolija, R. Kotte, A. Lebedev, K.S. Lee, Y. Leifels, A. LeFevre, P.

Loizeau, X. Lopez, M. Marquardt, J. Marton, M. Merschmeyer, M. Petrovici, K. Piasecki, F. Rami, V.

Ramillien, A. Reischl, W. Reisdorf, M.S. Ryu, A. Schüttauf, Z. Seres, B. Sikora, K.S. Sim, V. Simion,

K. Siwek-Wilczynska, K. Suzuki, Z. Tyminski, J. Weinert, K. Wisniewski, Z. Xiao, H.S. Xu,

J.T. Yang, I. Yushmanov, V. Zimnyuk, A. Zhilin, Y. Zhang, J. Zmeskal

and J. Aichelin, E. Bratkovskaya, W. Cassing, C. Hartnack, T.Gaitanos, Q. Li, D. Cozma

IPNE Bucharest, Romania, ITEP Moscow, Russia CRIP/KFKI Budapest, Hungary, Kurchatov Institute

Moscow, Russia, LPC Clermont-Ferrand, France, Korea University, Seoul, Korea, GSI Darmstadt, Germany, IReS Strasbourg, France, FZ Rossendorf, Germany, Univ. of Heidelberg, Germany, Univ. of Warsaw, Poland, RBI Zagreb, Croatia, IMP Lanzhou, China, SMI Vienna, Austria, TUM, Munich, Germany + P. Kienle (TUM),

T.Yamazaki(RIKEN)

SFAIR 2013 – Yvonne Leifels

Thank you

Star clusters young and old Chris Hetlage

APOD 2006, September 10

NUSYM 2013 – Yvonne Leifels FOPI

ASY-EOS

HADES

FOPI

KAOS

Inside IQMD

Y. Leifels – ASTRO 2013 20

after the convolution of the Skyrme type potentials supplemented by momentum dependent interactions (mdi) for infinite saturated nuclear matter at equilibrium

Testing density – Kaon production below threshold

Y. Leifels – SFAIR 2013 21

Independent on models and

details of the input (cross

sections, in medium

potentials etc.)

Testing densities at 2-3 ρ0

Data: C. Sturm et al., PRL 86 (2001) 39

IQMD: C. Hartnack et al., PRL96:012302,2006

RQMD: C. Fuchs et al., PRL 86 (2001) 1974

KAOS

Summary and conclusions

Y. Leifels – Texas 2013 22

At ~ (2-3)ρ0 data is consistent with a

soft Skyrme type EOS for symmetric

matter

confirmed for two different

observables within the same model,

which is describing reasonably well

all reaction data in this energy regime

absolute value may still model

dependent

more data will available at higher

densities with CBM@FAIR or NICA

In the relevant density regime soft

Skyrme type EOS follows closely the

A18+UIX+δν EOS of Akmal,

Pandharipande, Ravenhall

Phys. Rev. C, 58 (1998) 1804

Summary and conclusions

Y. Leifels – Texas 2013 23

Symmetry energy at supra-saturation densities

very few data points at supra saturation densities (experiments at GSI)

elliptic flow data

consistent with L~100+/- 45 MeV

slightly harder than experiments at lower densities/astrophysical

observations

pion ratio, but no consistent description, new experimental efforts at the

radioactive beam facility at RIKEN

more data WITH radioactive beams will be available soon

V2np

Bao-An Li, NUSYM 2013

Parameterization of

shape:

Elliptic flow of light clustered

Y. Leifels – Texas 2013 24

2)0(

2220

)0(

2

2220n2

Yvv)Y(v

vvv

A. L

eF

evre

et a

l, Nu

cl. P

hys. A

87

6 (2

01

2) 1

observable sensitive

to EOS over a large

energy range

protons and light

clustered

Soft EOS favored

Masses of neutron stars

Y. Leifels – ASTRO 2013 25

htt

p:/

/ww

w.s

tella

rco

llap

se

.org

/nsm

asse

s

Heaviest Neutron Stars

Name: J1614-2230

Mass: (1.976 0.04) M

P. Demorest et al. 2010

Shapiro delay

Name: J0348+0432

Mass: (2.01 0.04) M

J. Antoniadis et al. 2013

White dwarf spectroscopy

main sequence

neutron star binaries

white dwarf

neutron star binaries

double

neutron star binaries

X-Ray

optical binaries

What else?

Y. Leifels – ASTRO 2013 26

Hyperon production and propagation

YN and YY interaction in dense medium

Hypernuclei production

K-N interaction in dense medium

In-medium effects as a function of momentum and

density

“Hot” cluster formation

Phase transitions (QGP), new phases (SCC...)

Phase diagram of nuclear matter

Y. Leifels – ASTRO 2013 27

compression

heat

Z/N

Maximum compression reached at FAIR energies

Y. Leifels – FAIR Detectors 28

SIS 100/ 300

SIS AGS CERN SPS

optimum production of

baryons with strange quarks

maximum compression

in heavy-ion collisions

threshold for

strange quarks

threshold for

antiprotons

threshold for

charm quarks

1 10 100

ion energy [GeV/u]

nu

cle

ar

ma

tte

r d

en

sity (

blu

e c

urv

e)

Re

l.p

rod

uction

of str

an

ge

qu

ark

s (

red

cu

rve

)

To be determined:

Temperature

Pressure

Density

Observables:

Particle production

Flow of bulk matter

Production of D0, D±

, , e+e- or μ+μ-