Decoding the density dependence of the nuclear symmetry energy
The large imbalance in the neutron and proton densities in very neutron rich systems increases the nuclear symmetry energy so that it governs many aspects of neutron stars and their mergers. Extracting the density dependence of the symmetry energy therefore constitutes an important scientific object...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Elsevier
2022-07-01
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| Series: | Physics Letters B |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0370269322002325 |
| _version_ | 1818212991669108736 |
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| author | W.G. Lynch M.B. Tsang |
| author_facet | W.G. Lynch M.B. Tsang |
| author_sort | W.G. Lynch |
| collection | DOAJ |
| description | The large imbalance in the neutron and proton densities in very neutron rich systems increases the nuclear symmetry energy so that it governs many aspects of neutron stars and their mergers. Extracting the density dependence of the symmetry energy therefore constitutes an important scientific objective. Many analyses have been limited to extracting values for the symmetry energy, S0, and its “derivative”, L, at saturation density ρ0≈2.6×1014g/cm3 ≈0.16nucleons/fm3, resulting in constraints that appear contradictory. We show that most experimental observables actually probe the symmetry energy at densities far from ρ0, making the extracted values of S0 or L imprecise. By focusing on the densities these observables actually probe, we obtain a detailed picture of the density dependence of the symmetry energy from 0.25ρ0 to 2.0ρ0. From this experimentally derived density functional, we extract L01=54±6 MeV corresponding to the symmetry pressure of P01=1.8±0.2 MeV/fm3 at ρ≈0.10fm−3, a neutron skin thickness for P208b of Rnp=0.23±0.03 fm, and symmetry pressure at saturation density of P0=4.4±1.3 MeV/fm3. The extrapolated symmetry pressure at high density is consistent with results from recent measurements of neutron star radii from NICER and deformability from LIGO. |
| first_indexed | 2024-12-12T05:57:11Z |
| format | Article |
| id | doaj.art-3ad3bdd7275c44f7b2aa77dbe6d64178 |
| institution | Directory Open Access Journal |
| issn | 0370-2693 |
| language | English |
| last_indexed | 2024-12-12T05:57:11Z |
| publishDate | 2022-07-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Physics Letters B |
| spelling | doaj.art-3ad3bdd7275c44f7b2aa77dbe6d641782022-12-22T00:35:31ZengElsevierPhysics Letters B0370-26932022-07-01830137098Decoding the density dependence of the nuclear symmetry energyW.G. Lynch0M.B. Tsang1National Superconducting Cyclotron Laboratory, East Lansing, MI, 48824, USA; Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA; Corresponding authors.National Superconducting Cyclotron Laboratory, East Lansing, MI, 48824, USA; Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA; Corresponding authors.The large imbalance in the neutron and proton densities in very neutron rich systems increases the nuclear symmetry energy so that it governs many aspects of neutron stars and their mergers. Extracting the density dependence of the symmetry energy therefore constitutes an important scientific objective. Many analyses have been limited to extracting values for the symmetry energy, S0, and its “derivative”, L, at saturation density ρ0≈2.6×1014g/cm3 ≈0.16nucleons/fm3, resulting in constraints that appear contradictory. We show that most experimental observables actually probe the symmetry energy at densities far from ρ0, making the extracted values of S0 or L imprecise. By focusing on the densities these observables actually probe, we obtain a detailed picture of the density dependence of the symmetry energy from 0.25ρ0 to 2.0ρ0. From this experimentally derived density functional, we extract L01=54±6 MeV corresponding to the symmetry pressure of P01=1.8±0.2 MeV/fm3 at ρ≈0.10fm−3, a neutron skin thickness for P208b of Rnp=0.23±0.03 fm, and symmetry pressure at saturation density of P0=4.4±1.3 MeV/fm3. The extrapolated symmetry pressure at high density is consistent with results from recent measurements of neutron star radii from NICER and deformability from LIGO.http://www.sciencedirect.com/science/article/pii/S0370269322002325 |
| spellingShingle | W.G. Lynch M.B. Tsang Decoding the density dependence of the nuclear symmetry energy Physics Letters B |
| title | Decoding the density dependence of the nuclear symmetry energy |
| title_full | Decoding the density dependence of the nuclear symmetry energy |
| title_fullStr | Decoding the density dependence of the nuclear symmetry energy |
| title_full_unstemmed | Decoding the density dependence of the nuclear symmetry energy |
| title_short | Decoding the density dependence of the nuclear symmetry energy |
| title_sort | decoding the density dependence of the nuclear symmetry energy |
| url | http://www.sciencedirect.com/science/article/pii/S0370269322002325 |
| work_keys_str_mv | AT wglynch decodingthedensitydependenceofthenuclearsymmetryenergy AT mbtsang decodingthedensitydependenceofthenuclearsymmetryenergy |