Monopole Excitation and Nuclear Compressibility: Present and Future Perspectives
Abstract
Isoscalar giant resonances are nuclear collective excitations associated with the oscillation in phase of protons and neutrons according to a certain multipolarity $L$. In particular, the isoscalar giant monopole resonance ($L=0$) is the strongest nuclear compression mode, and its excitation energy is directly related to the compression modulus for finite nuclei. Typically, microscopic calculations are utilized to establish a relationship between the experimental compression modulus and the nuclear incompressibility that is a crucial parameter of the equation of state for nuclear matter. The incompressibility of nuclear matter has been determined with an accuracy of 10 to 20\% using relativistic and nonrelativistic microscopic models for describing the monopole distributions in ${}^{208}$Pb and ${}^{90}$Zr isotopes. However, the same theoretical models are not able to describe data for openshell nuclei, such as those of tin and cadmium isotopes. In fact, only effective interactions with a softer nuclearmatter incompressibility are able to predict the centroid energy of monopole distributions for openshell nuclei. An unified description of the monopole resonance in ${}^{208}$Pb and other openshell nuclei remains unsolved from the theory side. Most of this uncertainty is due to our poor knowledge of the symmetry energy, which is another essential component of the equation of state of nuclear matter. Therefore, new experimental data along isotopic chains covering a wide range in $N/Z$ ratios, including neutrondeficient and neutronrich nuclei, are of paramount importance for determining both the nuclearmatter incompressibility and the symmetry energy more precisely.
 Publication:

arXiv eprints
 Pub Date:
 June 2024
 DOI:
 10.48550/arXiv.2406.16217
 arXiv:
 arXiv:2406.16217
 Bibcode:
 2024arXiv240616217Z
 Keywords:

 Nuclear Theory;
 Astrophysics  High Energy Astrophysical Phenomena;
 Nuclear Experiment
 EPrint:
 In Oxford Research Encyclopedia of Physics