The symmetry energy at high density: new experimental results W. Trautmann GSI Helmholtzzentrum, Darmstadt, Germany Bormio th Meeting

The symmetry energy at high density: new experimental results W. Trautmann GSI Helmholtzzentrum, Darmstadt, Germany   1230 E sym (MeV)

Fuchs and Wolter, EPJA 30 (2006) the equation of state why so uncertain at high density? related to uncertainty of three-body and tensor forces at high density very generally: in-medium NN interaction normal nuclear density E sym

 =1.5  =0.5 param. in transport: UrQMD, Q.F. Li et al. Fuchs and Wolter, EPJA 30 (2006) the symmetry energy E sym = E sym pot +E sym kin = 22MeV·(ρ/ρ 0 ) γ +12MeV·(ρ/ρ 0 ) 2/3 L = 3ρ o ·dE sym /dρ at ρ=ρ 0 ρ/ρ0ρ/ρ0 γ L (MeV)

slide from talk of X. Viñas, ECT*, Trento, June 2011

PREX I A Pb PV = 656 ± 60 (stat) ± 14 (syst) ppb R n − R p = − 0.18 neutron radius of 208 Pb from parity-violating electron scattering Hall A Jefferson Lab polarized e GeV ≈ 60 μA 208 Pb target twin HRS θ lab ~ 5 o nearly only elastic events weak charge of the proton: 1-4sinθ W sinθ W =0.23 arXiv: distorted wave

neutron skin and the symmetry energy slide from talk of X. Viñas, ECT*, Trento, June % error as predicted in proposal experim. result of PREX-I (as given in proposal for PREX-II) Roca-Maza et al., PRL 106, (2011) "... without assumption on the neutron density shape. Δr np = 0.02 fm (~1%) supported by theory."

neutron skin and the symmetry energy slide from talk of X. Viñas, ECT*, Trento, June 2011 error as predicted in proposal experim. result of PREX-I (as given in proposal for PREX-II) Roca-Maza et al., PRL 106, (2011) LAND/GSI δ np = 0.17 ± 0.02 A.Klimkiewicz, PRL (2007) RQRPA calculations by N. Paar

analysis of π - / π + ratios in Au+Au at 400 A MeV (FOPI data), W. Reisdorf et al. NPA (2007) π ratios + IBUU04: x=1 super soft flow ratios + UrQMD: = 0.94 ± 0.21 nearly linear Bormio 2010: supersoft symmetry energy from pion ratios ? Zhigang Xiao et al.,PRL 102, (2009)

differential flow in heavy-ion collisions minimizes role of isoscalar part of the EoS differential: neutrons vs. protons t vs. 3 He, 7 Li vs 7 Be,... UrQMD: significant sensitivity predicted for differential elliptic flow (Qingfeng Li and Paolo Russotto) reanalysis of FOPI-LAND data: γ pot = 0.9 ± 0.4 Russotto, Wu, Zoric, Chartier, Leifels, Lemmon, Li, Lukasik, Pagano, Pawlowski, Trautmann, PLB 697 (2011) 471

results from FOPI/LAND experiment reanalysis of Au+Au 400 A MeV data SB: shadow bar for background measurement PLAWA LAND 2 LAND 1 SBacceptance in p t vs. rapidity main yield here neutron squeeze-out: Y. Leifels et al., PRL 71, 963 (1993)

Forward Wall FOPI Outer Wall LAND CHIMERA

results from FOPI/LAND experiment  =1.5  =0.5 neutron/hydrogen FP1: γ = 1.01 ± 0.21 FP2: γ = 0.98 ± 0.35 neutron/proton FP1: γ = 0.99 ± 0.28 FP2: γ = 0.85 ± 0.47 adopted: γ = 0.9 ± 0.4 parameters in UrQMD, Q.F. Li et al.

FP1 FP2 Medium modifications (FU1, …) and momentum dependence (FP1, …) of nucleon-nucleon elastic Xsects Qingfeng Li et al., PRC 83, (2011) parameterizations in UrQMD w/o momentum dep.

new: result obtained with Tübingen QMD*) a 2 = 2v 2 with FOPI filter bands show uncertainty due to isoscalar field “soft to hard” conclusion in paper: super-soft not compatible with FOPI-LAND data difference of neutron and proton squeeze-outs Au A MeV asy-stiff asy-soft *) V.S. Uma Maheswari, C. Fuchs, Amand Faessler, L. Sehn, D.S. Kosov, Z. Wang, NPA 628 (1998) M.D. Cozma, PLB 700, 139 (2011); arXiv: with FOPI filter UrQMD: momentum dep. of isoscalar field momentum dep. of NNECS T-QMD: density dep. of NNECS asymmetry dep. of NNECS soft vs. hard EoS width of wave packets

pre-summary L=3ρ 0 ·∂E sym /∂ρ S 0 =E sym (ρ 0 ) IAS HIC PDR isobaric analog states Danielewicz/Lee 2008 heavy-ion collisions isospin diffusion, n/p ratios Tsang et al., 2009 symmetry pressure P 0 =(L/3)ρ 0 from elliptic n/p flow from M.B. Tsang et al., PRL 102, (2009) vertical lines: analyses with ImQMD (Zhang et al.) and IBUU04 (Li and Chen) pygmy dipole resonance Klimkiewicz et al see also “Complete Electric Dipole Response in 208 Pb” Tamii et al., PRL 107, (2011)

μ-ball, CHIMERA, ALADIN Tof-wall for impact parameter orientation and modulus ALADIN ToF wall four rings of μ-ball four rings of CHIMERA common cluster recognition method used for particle ID Large Area Neutron Detector LAND reactions studied in May Au A MeV 96 Ru A MeV 96 Zr A MeV SIS experiment S394 run in May 2011

authors of proposal 2009

Experiment S394, CHIMERA-Kraków-LAND-μBall-Zagreb- Daresbury-Liverpool et al., May 2011 Piotr Pawłowski

HIC scenario: fast neutron emission (mean field effect) and transformation of neutron into proton in inelastic channels (no-chemical equilibrium) isotopic particle (double) ratios static calc. for infinite nucl. matter FOPI data HIC Ferini et al.stiffer for ratio up Xiao et al.softer “ Feng and Jinstiffer “ consequence: extremely stiff (soft) solutions Au+Au PRC (2007) Reisdorf et al., NPA781(2007)

The SAMURAI TPC would be used to constrain the density dependence of the symmetry energy through measurements of: –Pion production –Flow, including neutron flow measurements with the nebula array. The TPC also can serve as an active target both in the magnet or as a standalone device. –Giant resonances. –Asymmetry dependence of fission barriers, extrapolation to r-process. The SAMURAI TPC would be used to constrain the density dependence of the symmetry energy through measurements of: –Pion production –Flow, including neutron flow measurements with the nebula array. The TPC also can serve as an active target both in the magnet or as a standalone device. –Giant resonances. –Asymmetry dependence of fission barriers, extrapolation to r-process. Device: SAMURAI TPC (U.S. Japan Collaboration) T. Murakami a, Jiro Murata b, Kazuo Ieki b, Hiroyoshi Sakurai c, Shunji Nishimura c, Atsushi Taketani c, Yoichi Nakai c, Betty Tsang d, William Lynch d, Abigail Bickley d, Gary Westfall d, Michael A. Famiano e, Sherry Yennello g, Roy Lemmon h, Abdou Chbihi i, John Frankland i, Jean-Pierre Wieleczko i, Giuseppe Verde j, Angelo Pagano i, Paulo Russotto i, Z.Y. Sun k, Wolfgang Trautmann l a Kyoto University, b Rikkyo University, c RIKEN, Japan, d NSCL Michigan State University, e Western Michigan University, g Texas A&M University, USA, h Daresbury Laboratory, i GANIL, France, UK, j LNS-INFN, Italy, k IMP, Lanzhou, China, l GSI, Germany Device: SAMURAI TPC (U.S. Japan Collaboration) T. Murakami a, Jiro Murata b, Kazuo Ieki b, Hiroyoshi Sakurai c, Shunji Nishimura c, Atsushi Taketani c, Yoichi Nakai c, Betty Tsang d, William Lynch d, Abigail Bickley d, Gary Westfall d, Michael A. Famiano e, Sherry Yennello g, Roy Lemmon h, Abdou Chbihi i, John Frankland i, Jean-Pierre Wieleczko i, Giuseppe Verde j, Angelo Pagano i, Paulo Russotto i, Z.Y. Sun k, Wolfgang Trautmann l a Kyoto University, b Rikkyo University, c RIKEN, Japan, d NSCL Michigan State University, e Western Michigan University, g Texas A&M University, USA, h Daresbury Laboratory, i GANIL, France, UK, j LNS-INFN, Italy, k IMP, Lanzhou, China, l GSI, Germany Nebula scintillators SAMURAI dipole TPC Q

SAMURAI dipole magnet at RIKEN Superconducting Analyzer for MUlti-particle from RAdio Isotope Beam with 7Tm of bending power

summary kaon and pion ratios interesting probes but results presently inconclusive: new activity at RIKEN (Samurai) and MSU L ≈ 60 MeV (γ ≈ 0.6) from nuclear structure and reactions probing densities of ≈ 2/3 ρ 0; big expectations on PREXII high-densities probed in reactions at SIS energies; wait for analysis of ASY-EOS experiment!

trasferimento corone al GSI settembre 2010 CHIMERA at LNS

installazione in Cave C al GSI

esperimento in maggio 2011 μ-ball around target Cracow hodoscope beam LAND

esperimento in maggio 2011 μ-ball around target enriched targets beam LAND

parameterization in the IBUU ρ/ρ0ρ/ρ0 E sym (MeV) best fits with UrQMD of Q.F. Li JPG 31 (2005) in comparison with FOPI/LAND v2 ratios  =1.5  =0.5

neutron skin and the symmetry energy Horowitz & Piekarewicz, PRL 86 (2001): a data-to-data relation between the neutron skin of a heavy nucleus and the crust of a neutron star JLAB E-003 A CLEAN MEASUREMENT OF THE NEUTRON SKIN OF 208 Pb THROUGH PARITY VIOLATING ELECTRON SCATTERING The Lead Radius Experiment (PREX) measures the parity violating asymmetry A pv for GeV electrons scattering from 208 Pb at 5 degrees. This measurement should be sensitive to the neutron r.m.s radius of 208Pb to 1%. neutron stars 3x kg 208 Pb nucleus 3x kg δrδr electron fraction neutron skin

from “Complete Electric Dipole Response in 208Pb” Tamii et al., arXiv: FIG. 5: (Color online) Extraction of the neutron skin in 208Pb based on the correlation between rskin and the dipole polarizability αD established in Ref. [8]. [8] P.-G. Reinhard and W. Nazarewicz, Phys. Rev. C 81, (R) (2010).