-- YvonneLeifels - 23 May 2010

Collaboration Meeting

Schedule of experiment

Test experiment should take place in first week of November. Chimera will be moved to GSI in September 2010. Some space will be needed to store the boxes until the CAVE C will be reopened after the LAND experiments taking place during August/September 2010. After the reopening of the CAVE the area behind the ALADIN magnet needs to be cleared from the experimental set-up. According to H. Simon this will take just a few days (2-3?). Then Chimera can be set-up in the experimental hall.

TOF wall

TOF wall is decabled and in the FOPI cave where it can be recabled and tested. Kaled will come with students in July/September to work on the TOF wall. Notes: The processor for read-out of the fastbus crate is in the ELEX. For slow control of the CFDs one needs a processor but it is unclear where it is. Check whether this can be done via one of the processors in VME instead of the PC which was used by Take)

Califa

Modules are available but mechanical integration is needed. Set-up in the CAVE is still unclear. One needs the technical drawings of all detectors best in one common data format.

Microball

Only part of the micro ball needed (rings 5, 6, 7, 8). Forward part is covering LAND or the charged particle detectors, and backward part is hindering the introduction of a reaction counter. It will give an additional particle multiplicity in the backward hemisphere which is necessary to disentangle the Zirkonium reactions from the Oxygen reactions when using the ZrO2 target.plus an additional estimation of the reaction plane.

DAQ

The non MBS DAQ systems will be connected via a trigger bus

Simulations

Sunday morning

Many body problem in EOS

  • non relativistic approach

non relativistic pointlike protons and neutrons interacting via a non-relativic hamiltonian

* started by brueckner: brueckner-bethe-goldstone theory of nuclear matter

introducing the auxilaiary single-aparticle potential U

diagrams in the expansion are grouped according to the order of correlations they describe (two, three-body)

two body correlations - G-matrix G is solution of Bethe - Goldstone equation (bare nucleon-nucleon potential, pauli operator, single particle energies), describes the interaction in the medium

result is EOS: derivative of binding energy

including three body correlations leads to the bethe-fadeev equation

EOS does not depend much on the choice of the single particle potential

  • alternative: variational method (Pandharipande)

Method use to calculate the upper bound of ground state energies

  • Differences between BBG and Variational method:
same results on two body level

  • Problem of non-relativstic models: they do not fit the saturation point, when three hole - line diagrams are included an dmoder NN interactions are used the Coeser band reduces to a Coester island. saturation point still missed.

  • Three nucleon forces (TBF): Including a Delta is intermediate particles in pion exchange or the roper resonance. Fits the saturation point.

  • Microscopic model: exchange of pi, rho, siggma, omega etc.

  • prc 74 047304 (2006) collection of NN potentials

Two body force potentials are wrong (saturation point wrong).

DBHF most repulsive one

2BF + micro TBF more repulsion

2bf too strong binding

  • Symmetry energy: parabolic expansion

TBF makes symmetry energy stiffer then normal BHF, at saturation 28.5 < Esym < 32.6 Mev.

  • Extension of BHF calculations to finite T

Liquid gas phase transition with T=19 Mev and rho_c ~ 0.06 fm-3

Parabolic expansion still ok.

  • Determination of EOS with HI flow

Pressure determined from buu calculations

Flow data exclude stiff equations of state at low density

At high density the EOS is not constrained because the different EOS are diverging and

  • Astrophysical objects

Mass radius relation of neutron star

Direct URCA process n -> p + e- + anti nu, difference of chemical potentials depends on the symmetry energy

  • EOS at finite T

Structure of proto neutron stars

  • useful parametrizations of the EOS for your simulations

E/A = alpha * rho + beta rho**gamma

  • Limits

TBFs at density rho > 0.4 fm-3 unknown, Particle production etc., unknown potentials for these interactions, ASY-Soft excluded from microscopic approaches

BUT pion production not considered, approach can strictly only be used as long as there is no particle production

EOS for infinite matter, do Brueckner calculations for finite matter

Cannot be put in the transport codes directly, because it is not an equilibrated matter (check publications of Fuchs) and phase space distributions have to be taken into account or corrected appropriately

Since momentum dependence is already in, derivation is depending on the momentum distribution which is used in the calculations.

Evolution with density does not only depend on density. At normal nuclear matter density the chiral condensate is already changing, the interactions are changing, which is the tentative reason why three body forces have to be included.

ASY eos in the core crust transition

Transition between crust und liquid phase of neutron star, depending on ASY EOS

nucl-the: 1004.5197 http://arxiv4.library.cornell.edu/pdf/1004.5197v1

ASY EOS from nuclear structure

Pygmy dipole resonance ecsess neutrons vibrating against protons

  • theory based on energy density functionals (self consistent mean field and extensions), they alos provide links with the equation of state (EOS)
  • EDFs minimasation of energy either within relativistic and non-relativistic framework (hatree-fock and hatree equations)
  • 8-10 free parameters: Skyrme/Gogny vs. RMF/RHF
  • Linear response theory to describe small oszillations
  • Dipole resonance exhausts the whole sum rule its energy can be deduced following th formulas given by Lipparini and Stringari.
  • Access symmetry energy via local density approximation
  • If only volume, b is only bvol and equals S(rho0) = J

land pygmy: few interactions have been used to check correleations

paring in 130 Sn

other pygmy diple states existing

collectivity?

  • rising experiment measured gamma decay directly

experimental data suggests: L = 65.1 +/- 15.5 MeV PRC 81 041301 (r) (2010), shifts L to somewhat larger values.

pdr from sn not really consistent with HIC data

  • Correlation between L and neutron radii

  • symmetry energy from charge - exchange states: wich states are collective and well-known - e.g. isobaric analog state, energy normalized to the total mass of the nucleus. macroscopic formula + shell effects

Isospin diffusion

Topic revision: r2 - 2010-05-24, YvonneLeifels
 
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