Constraining the slope parameter of symmetry energy from nuclear - PowerPoint PPT Presentation

Constraining the slope parameter of symmetry energy from nuclear structure International Symposium on Neutron Star Matter (NSMAT2016) - Recent Progress in Observations, Experiments and Theories - November 21 st – 24 th , 2016 Tohoku University INAKURA Tsunenori (Niigata Univ.) NAKADA Hitoshi (Chiba Univ.)

Nuclear Matter Equation of State (EoS) EoS calculated by effective interactions PNM � Symmetric Nuclear Matter (SNM) EoS is known rather well. � Pure Neutron Matter (PNM) EoS has large uncertainty. SNM

Quantities characterizing EoS

Low-Energy Dipole (LED) mode Pygmy Dipole Resonance (PDR) � Emerge around (neutron) threshold. � Observed in many nuclei. � develop well in neutron-rich nuclei. � connected with neutron skin which is approximately neutron matter. • LED ≈ neutron skin dynamics. • LED may provide some information on EoS in � ≤ � � region.

L from LED Reinhard+, PRC81, 051303 Roca-Maza+, PRC88, 024316 Carbone+, PRC81, 041301 Which is best?

L from LED Reinhard+, PRC81, 051303 Roca-Maza+, PRC88, 024316 Carbone+, PRC81, 041301 Correlation is analyzed Correlation is calculated using many interactions. within single interaction. Same correlation?

L from LED Reinhard+, PRC81, 051303 Roca-Maza+, PRC88, 024316 Carbone+, PRC81, 041301 Which is best? Same correlation?

Selfconsistent mean-field calc. (density functional theory) • Hartree-Fock + Random Phase Approximation. • Fully self-consistent calculation. 16 interactions � 3 Skyrme which are widely used: SkM*, SLy4, SGII � 2 Skyrme which are less used: SkT4, Ska � 2 Skyrme which are recently made: UNEDF0, UNEDF1 � 4 Skyrme to cover wide range of L : SkI2, SkI3, SkI4, SkI5 � 3 Gogny and 2 M3Y to check model dependence: D1, D1S, D1M, M3Y-P6, M3Y-P7

Introduction of L -dependence Ono+, PRC68, 051601 The additional term � does not affect SNM EoS nor S 0 . � changes L . V L is a parameter to control L .

Correlations in 132 Sn Correlation coefficient � = 0.953. Uncertainty for L : 12 MeV.

Comparison with experimental data Assuming � � = 30 – 32 MeV. 68 Ni experimental data: Rossi+, PRL111, 242503. 208 Pb experimental data: Tamii+, PRL107, 062502.

Summary We calculate correlations between and observables using many interactions and their variants. • LED provides constraint on PNM EoS. • α D S 0 correlates well with slope parameter L . • Theoretical uncertainty (standard deviation) is 10-20 MeV. Inakura and Nakada, Phys. Rev. C 92, 064302.