scholarly journals Systematics of the electric dipole response in stable tin isotopes

2018 ◽  
Vol 178 ◽  
pp. 03008 ◽  
Author(s):  
Sergej Bassauer ◽  
Peter von Neumann-Cosel ◽  
Atsushi Tamii
Keyword(s):  
Electric Dipole ◽  
Strength Function ◽  
Research Centre ◽  
Underlying Structure ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Proton Scattering ◽  
Heavy Nuclei ◽  
Scattering Experiment ◽  
Dipole Response

The electric dipole is an important property of heavy nuclei. Precise information on the electric dipole response provides information on the electric dipole polarisability which in turn allows to extract important constraints on neutron-skin thickness in heavy nuclei and parameters of the symmetry energy. The tin isotope chain is particularly suited for a systematic study of the dependence of the electric dipole response on neutron excess as it provides a wide mass range of accessible isotopes with little change of the underlying structure. Recently an inelastic proton scattering experiment under forward angles including 0º on 112,116,124Sn was performed at the Research Centre for Nuclear Physics (RCNP), Japan with a focus on the low-energy dipole strength and the polarisability. First results are presented here. Using data from an earlier proton scattering experiment on 120Sn the gamma strength function and level density are determined for this nucleus.

Formation of α clusters in dilute neutron-rich matter

Science ◽  
2021 ◽  
Vol 371 (6526) ◽  
pp. 260-264 ◽  
Author(s):  
Junki Tanaka ◽  
Zaihong Yang ◽  
Stefan Typel ◽  
Satoshi Adachi ◽  
Shiwei Bai ◽  
...  
Keyword(s):  
Cross Sections ◽  
Cluster Formation ◽  
Reaction Cross ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Heavy Nuclei ◽  
Α Decay ◽  
Neutron Skin Thickness ◽  
Reaction Cross Sections ◽  
Α Particles

The surface of neutron-rich heavy nuclei, with a neutron skin created by excess neutrons, provides an important terrestrial model system to study dilute neutron-rich matter. By using quasi-free α cluster–knockout reactions, we obtained direct experimental evidence for the formation of α clusters at the surface of neutron-rich tin isotopes. The observed monotonous decrease of the reaction cross sections with increasing mass number, in excellent agreement with the theoretical prediction, implies a tight interplay between α-cluster formation and the neutron skin. This result, in turn, calls for a revision of the correlation between the neutron-skin thickness and the density dependence of the symmetry energy, which is essential for understanding neutron stars. Our result also provides a natural explanation for the origin of α particles in α decay.

scholarly journals Microscopic description of the pygmy dipole resonance in neutron-rich Ca isotopes

2018 ◽  
Vol 194 ◽  
pp. 04002
Author(s):  
N.N. Arsenyev ◽  
A.P. Severyukhin ◽  
V.V. Voronov ◽  
N.V. Giai
Keyword(s):  
Electric Dipole ◽  
Random Phase Approximation ◽  
Strength Function ◽  
Random Phase ◽  
Strength Distribution ◽  
Low Energy ◽  
Dipole Strength ◽  
Quasiparticle Random Phase Approximation ◽  
Dipole Resonance ◽  
Dipole Response

We study the effects of the phonon-phonon coupling on the low-energy electric dipole response within a microscopic model based on an effective Skyrme interaction. The finite rank separable approach for the quasiparticle random phase approximation is used. Choosing as an example the isotopic chain of Calcium, we show the ability of the method to describe the low-energy E1 strength distribution. With one and the same set of parameters we describe available experimental data for 48Ca and predict the electric dipole strength function for 50Ca.

scholarly journals Sensitivity of the electric dipole polarizability to the neutron skin thickness in [sup 208]Pb

2012 ◽  
Author(s):  
X. Roca-Maza ◽  
B. K. Agrawal ◽  
G. Colò ◽  
W. Nazarewicz ◽  
N. Paar ◽  
...  
Keyword(s):  
Electric Dipole ◽  
Dipole Polarizability ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Neutron Skin Thickness

scholarly journals Nuclear Symmetry Energy Effects on the Bulk Properties of Neutron-rich Finite Nuclei

2020 ◽  
Vol 27 ◽  
pp. 91
Author(s):  
Manolis Divaris ◽  
Charalampos Moustakidis
Keyword(s):  
Symmetry Energy ◽  
Dominant Role ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Nuclear Symmetry Energy ◽  
Heavy Nuclei ◽  
Isospin Asymmetry ◽  
Asymmetry Function ◽  
Finite Nuclei ◽  
Dependent Interaction

We systematically study the effect of the nuclear symmetry energy in the basic properties of finite, neutron-rich, heavy nuclei where symmetry energy plays a dominant role. We employ a variational method, in the framework of the Thomas-Fermi approximation, to study the effect of the symmetry energy on the neutron skin thickness and symmetry energy coefficients of various nuclei. The isospin asymmetry function a(r) is directly related to the symmetry energy as a consequence of the variational principle. In addition to this, the Coulomb interaction is included in a self-consistent way. The energy density of the asymmetric nuclear matter that is used, has its origins in a momentum-dependent interaction.

scholarly journals Bootstrap analysis of the correlation between neutron skin thickness and the slope of symmetry energy

2020 ◽  
Vol 29 (07) ◽  
pp. 2050054
Author(s):  
A. Pastore
Keyword(s):  
Symmetry Energy ◽  
Correlation Coefficients ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Density Range ◽  
Density Functionals ◽  
Heavy Nuclei ◽  
Bootstrap Analysis ◽  
Isospin Asymmetry ◽  
Neutron Skin Thickness

This work illustrates the use of bootstrap methods to quantify the statistical uncertainties on the correlation coefficients between the slope of the symmetry energy and the neutron skin thickness in heavy nuclei. By using several energy density functionals, I discuss the density dependence of such a correlation and its evolution with isospin asymmetry. In particular, I observe that the correlation between the slope of the symmetry energy and the neutron skin is present not only at saturation density, but over a much larger density range.

scholarly journals Neutron skin thickness from the measured electric dipole polarizability inNi68,Sn120, andPb208

2015 ◽  
Vol 92 (6) ◽  
Author(s):  
X. Roca-Maza ◽  
X. Viñas ◽  
M. Centelles ◽  
B. K. Agrawal ◽  
G. Colò ◽  
...  
Keyword(s):  
Electric Dipole ◽  
Dipole Polarizability ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Neutron Skin Thickness
Sign in / Sign up

Export Citation Format

Share Document