INDRA GANIL experiments: Equilibrium constantsINDRA versus Texas A&M: K c (4He) INDRA Equilibrium...
Transcript of INDRA GANIL experiments: Equilibrium constantsINDRA versus Texas A&M: K c (4He) INDRA Equilibrium...
INDRA GANIL experiments:
Equilibrium constants“Valid treatment of the correlations and clusterization in low density matter”
R. Bougault, LPC Caen
INDRA collaboration
(work related to Quin et al. publication Texas A&M)
RIN FIDNEOS
Astrophysics: life cycle of a star
Light and Heavy clusters are present
• In inner crust of neutron stars (cold stellar matter)
• In core-collapse supernova matter (warm nuclear matter)
Astrophysics: life cycle of a star
Core Collapse: electron capture on protons (free or within nuclei) reduces the electronfraction and realeases neutrinos.Trapping of neutrinos could halt the process: reabsorption of the neutrinos on neutrons (free or within nuclei) - neutrino opacity.
Astrophysics: CCSNe
Cold Neutron Star
2.Neutronization &
by
emission
csm.ornl.gov
Cooling
neutrino
EXPLOSION of CORE COLLAPSE SUPERNOVAEAccretion of matter onto the central object, known as the proto-neutron star (hot and lepton rich)
Clusters influence supernova properties: the clusters can modify the neutrino transport, affecting the cooling of the proto-neutron star.
Astrophysics: CCSNe
Cold Neutron Star
2.Neutronization &
by
emission
csm.ornl.gov
Cooling
neutrino
EXPLOSION of CORE COLLAPSE SUPERNOVAEAccretion of matter onto the central object, known as the proto-neutron star (hot and lepton rich)
Actual CCSNe Nuclear Statistical Equilibriummodels does not include d, t, 3He, Li light clusters.
Astrophysics: CCSNe
Cold Neutron Star
2.Neutronization &
by
emission
csm.ornl.gov
Cooling
neutrino
EXPLOSION of CORE COLLAPSE SUPERNOVAEAccretion of matter onto the central object, known as the proto-neutron star (hot and lepton rich)
Color: electron fraction
• From Symmetric matter (0.5) red
• To Neutron matter (0) blue
T. Fischer et al. Astro. Phys. Journal 194:39 (2011)
Phase space covered in
Core-Collapse Supervova
simulations
Astrophysics: supernova modelisation
Questions for nuclear physics: what is the chemical composition at these densities and temperatures & measure in medium effects.
15 MSUN progenitor
1st second
post-bounce evolution
TE
MP
ER
AT
UR
E (
MeV
)
Baryon DENSITY (fm-3)
TE
MP
ER
AT
UR
E (
MeV
)
Baryon DENSITY (fm-3)
Color: electron fraction
• From Symmetric matter (0.5) red
• To Neutron matter (0) blue
T. Fischer et al. Astro. Phys. Journal 194:39 (2011)
Phase space covered in
Core-Collapse Supervova
simulations15 MSUN progenitor
Astrophysics: supernova
HEAVY ION COLLISIONS
How to create low density nucl. matter
STUDY of a Gas
composed of light clusters
formed
in central collisions
INDRA@GANIL136,124Xe+124,112Sn 32 A MeV
Treatment of the gas material in a statistical/equilibrium
framework(equilibrium demonstration: R. Bougault et al. PRC 97(2018)024612)
136Xe
There is
• Temperature & expansion:
hot expanding source
• Coulomb effects:
corrections to go back to the
original velocity spectra at
cluster creation time
Original velocity spectra at cluster creation time
1- Coulomb correction
The velocity is a clock:
each velocity bin
represents the state of
the evolving source at
a given time.
2- Hot expanding source
J. Wang et al. PRC72 (2005) 024603
<E
mis
sio
n tim
e>
(fm
/c)
AMD-V model
Statistical/equilibrium framework
For each Vsurf bin (i.e. time)1- Temperature: from Yields (2H 4He)/(3H 3He)
S. Das Gupta and A.Z. Mekjian Phys. Rep. 72 (1981) 131
S. Albergo et al. Nuovo Cimento 89 (1985) 1
3- Momentum space density Power law:
2- Neutrons: from Yields (3H/3He)
Cluster momentum spectrum versus (proton momentum spectrum)A
(neutron spect. = proton spect., Coulomb correction)
Statistical/equilibrium framework
For each Vsurf bin (i.e. time)1- Temperature: from Yields (2H 4He)/(3H 3He)
S. Das Gupta and A.Z. Mekjian Phys. Rep. 72 (1981) 131
S. Albergo et al. Nuovo Cimento 89 (1985) 1
3- Momentum space density Power law:
2- Neutrons: from Yields (3H/3He)
VOLUME measurement DENSITY
Density: low values are achieved
Temperature and proton fraction
T = few MeV Yp = entrance chan.
(T, r, Yp) useful for CCSNe
Mass fractions: N/Z dependence
FERMIONS
BOSONS
FERMIONS
Equilibrium constant Kc
Z 11𝐻 + (𝐴 − 𝑍) 0
1𝑛 ↔ 𝑍𝐴𝑋
Law of mass action (Guldberg et Waage)Equilibrium, same phase.
aA+bB↔gC+dDConstant Kc is relative to concentrations and stoichiometric coef.
Kc = ([C]g.[D]d)/([A]a.[B]b)
The equilibrium reaction is characterized by Kc whose value is constant for a given reaction and a given temperature.
Gas of protons & neutrons in equilibrium with clusters
Basic chemistry course!!!
The equilibrium constant is a universal characteristics
Equilibrium constant Kc
no N/Z dependence
Equilibrium constant Kc: Texas A&MData from NIMROD detector
TEXAS A&M
(mid-rapidity region, central collisions)
AT VERY LOW DENSITIES
Z 11𝐻 + (𝐴 − 𝑍) 0
1𝑛 ↔ 𝑍𝐴𝑋
INDRA versus Texas A&M: Kc (4He)
INDRA
Equilibrium constant values are different
INDRA versus Texas A&M: Temp.
INDRA
The thermodynamical paths are different
Relativistic Mean-Field with clusters
RMF approach: clusters as new degrees of freedom, with effective mass dependent on density.• In-medium effects: clusters interact with medium via the mesoncouplings, or effective mass shifts, or both
Helena Pais (CFisUC, University of Coimbra, visitor LPC), F. Gulminelli (LPC-Caen),
C. Providência (Univ. Coimbra), G. Roepke (Univ. Rostock).
Change the cluster effective mass
Broadly speaking:Free nucleons & nucleons within nuclei: same mean-field (Xs=1)Free nucleons & nucleons within nuclei: different mean-field (Xs<1)
H. Pais et al. PRC97, 045805 (2018) – H. Pais et al. PRC99, 055806 (2019)
Relativistic Meam-Field versus DATA
INDRA & RMF Texas A&M & RMF
1) Clear deviations from Ideal gas: in medium effectsare present
2) Some deviations data/RMF calculations at very lowdensitiesindra Xs=0.9 while Texas A&M Xs=0.85
Conclusions• Nuclear matter characterization at very low densities is
possible using Heavy-ion reactions
• NM is far away from Ideal Gas hypothesis
• In-medium effects are present: nucleons within clusters
have to be treated differently as compare to free
nucleons.
• Implication: mean-field effets, binding energy shift,…
• CCSNe: EOS and neutrino opacity (clusters)
• The work is in progress to explain the difference between
the two experiments, improved method to extract
temperature and density: INDRA + H. Pais (CFisUC,
Univ. of Coimbra, visitor LPC), F. Gulminelli (LPC-Caen),
C. Providência (Univ. Coimbra), S. Mallik (Variable
Energy Cyclotron Centre, Kolkata, visitor LPC) and
discussion with Texas A&M.