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This study examines the conclusion using the interplay of nuclear incompressibility and symmetry energy. It explores the relationship between KA and K∞, and the effects of Kτ and KCoul on K∞.
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Purpose: Elaborate on the conclusion 230 < K < 250 MeV, by exploting the interplay of nuclear incompressibility and symmetry energy.
KA = K + Ksurf A-1/3 + Kτδ2 + KCoul Z2 A-4/3 We do not discuss the old macroscopic approach (unreliable, cf. [1]), but the above expression can be used in connection with the microscopic models, which allow calculating the parameters (no fit !). In many attempts to deduce K from the ISGMR the linear relation between KAand K was assumed. Cf. J.P. Blaizot. [1] M. Pearson, Phys. Lett. B271 (1991) 12; S. Shlomo and D. Youngblood, Phys. Rev. C47 (1993) 529.
Ksurf= cK with c ~ -1 (cf. Ref. [1]). True ?? KA = K(non rel.)(1+cA-1/3) + Kτ(non rel.)δ2 + KCoul(non rel.) Z2 A-4/3 KA = K(rel.)(1+cA-1/3) + Kτ(rel.)δ2 + KCoul(rel.) Z2 A-4/3 KCoul should not vary much from the non-relativistic to the relativistic description. But since both the terms which include K and Kτ contribute, a more negative Kτcanlead to a the extraction of a larger K (and vice-versa). Remember: Kτis negative and depends on the density dependence of the symmetry energy ! [1] M. Centelles et al., Phys. Rev. C65 (2002) 044304
SLy4 protocol, α=1/6 MICROSCOPIC (!) CHF K around 230-240 MeV.
α=0.3563, • neglect of the Coulomb exchange • and center-of-mass corrections in the • HF mean field. The result of B.J. Agrawal et al., is consistent with this plot !
There has been a claim that the different behaviour of relativistic and non-relativistic models has its origin in the different density dependence of the symmetry energy curve S(ρ). Skyrme forces: softer symmetry energy (values at saturation around 26-32 MeV). RMF: stiffer. Constrained by -meson coupling gρ. J. Piekarewicz, PRC 66 (2002) 034305. C: 28 MeV B: 37 MeV ←“softening” (~ 0.5 MeV)
The symmetry energy (Esym or S) All these forces fit finite nuclei: with different values of J and of the derivatives of S
How to experimentally discriminate between models ? E ~ A-1/3 δE/E = δA/3A Even if we take a long isotopic chain of stable, spherical isotopes: Sn → δE/E is of the order of 3%, that is, 0.45 MeV (≈ 2σexp). Calculations should be made at the same level of accuracy.