Limits of applicability of the currently available EoS at high density matter in neutron stars and

core-collapse supernovae:Discussion comments

Workshop on the Physics of Nucleons and Nuclei 16-17 October 2006 SURA, Washington DC

J.R.StoneOxford University, Oxford, United KIngdom

Physics Division, ORNL, Oak Ridge TNDepartment of Chemistry and Biochemistry,

University of Maryland, College Park, MD

3. How sensitive are present experimental data on finite nuclei and astrophysical objects made of uniform baryon matter to the physics underlying our models? Is there any way we could identify individual model parameters (or a group of parameters) to a particular observable (or a class of observables) and thus control its (their) modelling?

2. Recognition of the true limits of the applicability of the current models for EoS at high density. At what density and temperature the baryons start to loose their identity as composite particles and the mixed-phase and pure quark-based models are essential? Relativistic effects?

1. Seek reduction of the number of variable parameters of the baryon-baryon interaction in medium and convergence of different nuclear and particle physics models to the most essential physics, important in nuclei and high density matter.

Interaction ncmax[fm-3] R [km] Mg/Ms

APR 1.14 10.01 2.20 SkM* 1.66 8.95 1.62 SLy4 1.21 9.96 2.04

Does extrapolation

matter?

What happensat densitieshigher then

3 x n0?

(n0 = 0.16 fm-3)

Dirac- Brueckner-Hartree-FockGroningen, Bonn A, DD pheno.Hofmann et al, PRC 64, 025804

Brueckner-Hartree-FockNijmegen potentialVidana et al, PRC 62,035801B

eta

stable

mattter

Relativistic quark-qluon coupling model: P.Guichon et al.

N attractive: 7 hypernuclear events: U~ -28 MeV at n=n0

quasi-free production of : U~ -18 MeVN attractive: hypernuclei A=3-209: U~ -30 MeV at n=n0

N ? : - atoms: repulsive +

He hypernucleus bound by isospin forces

Menezes and Providencia, PRC 68, 035804 (2003)

MIT bag+Non-linear WaleckaRMF with GLinteractionfull baryon octetMmax ~ 1.4-1.6 Msolar

Nambu-Jona-Lasinio+Non-linear WaleckaRMF with GLinteractiomfull baryon octetMmax ~ 1.8-1.9 Msolar

T=0 MeV T=20 MeV

E sat (MeV) nsat(fm-3) K [MeV]

DB(BA ) -15.59 0.185 290

DB(BC) -12.26 0.155 185

RMF -15.75 0.193 540 Li et al., PRC 45, 2782 (1992)

RMF

Sk

Sk

DB DB

AV14

Calculated neutron skin in 208Pb for 87 Skyrme modelsin comparison with experimental data

Experimentaldata on neutron skinsfrom proton scatteringare model dependent!Clark et al.PRC 67, 054605 (2003)

Most precise data (1.5%)from atomic parityviolation measurementin electron scatteringat JLAB expected inabout 2 yearsHorowicz et al.PRC63, 025501 (2001)

Relative magnitude of the skin effect: not isospin dependent

Surface effects – shape of the last occupied orbital at Fermi surface?

Z N N-Z

40 82 42 28 50 22 50 82 32 20 28 8 82 126 44

{

Work inProgress! (2004)

Mass:

1.2 – 2.2 Solar

Radius:

The Sun: 670 000 km

NS : 10 – 14 km

W. G. Neutron, JRS – 3D temperature dependent HF+BCS calculation of nuclear matter (with the Skyrme interaction as yet…)

Transition to uniform matter as a function of density and temperature:=0.04,0.08,0.12 fm-3 left to rightT=0 MeV (top) T=5 MeV (bottom)

Minimization of the total free energyas a function of the number of particles in the unit cell

Assumption: nuclear matter is modeled as an infinite sequence of unit cells with periodic boundary conditions.