Machine learning transforms the inference of the nuclear equation of state

Our knowledge of the properties of dense nuclear matter is usually obtained indirectly via nuclear experiments,astrophysical observations,and nuclear theory calculations.Advancing our understanding of the nuclear equation of state(EOS,which is one of the most important properties and of central interest in nuclear physics)has relied on various data produced from experiments and calculations.We review how machine learning is revolutionizing the way we extract EOS from these data,and summarize the challenges and opportunities that come with the use of machine learning.

Towards the continuum coupling in nuclear lattice effective field theory Ⅰ: A three-particle model

Weakly bound states often occur in nuclear physics.To precisely understand their properties,the coupling to the continuum should be worked out explicitly.As the first step,we use a simple nuclear model in the continuum and on a lattice to investigate the influence of a third particle on a loosely bound state of a particle and a heavy core.Our approach is consistent with the Lüscher formalism.

Theoretical Design of a 104MHz Ladder Type IH-RFQ Accelerator

Beam dynamics and rf designs of a 104 MHz ladder type IH-RFQ （L-IH-RFQ） accelerator are finished at Peking University for the acceleration of 14C＋ from 40 keV to 500 keV. As a specific feature, the output beam energy spread is as low as 0.6% achieved with the internal discrete bunching method, which makes potential applications of RFQ feasible, such as accelerator mass spectrometry and ion implantation. Tolerances of the beam dynamics design are studied by means of changing the input beam parameters, and the results are quite satisfying. On the other hand, the L-IH-RFQ structure is employed, taking advantage of its mechanical stability and the absence of inter-electrode voltage asymmetry. Radio-frequency properties are studied and optimized for reducing power loss with Microwave Studio （MWS）. Tuning of the field flatness and frequency is investigated in principle.

Global dynamical correlation energies in covariant density functional theory： Cranking approximation

Tje global dynamical correlation energies for 575 even even nuclei with proton numbers ranging from Z = 8 to Z = 108 calculated with the covariant density functional theory using the PC-PK1 parametrization are presented. The dynamical correlation energies include the rotational correction energies obtained with the cranking approximation and the quadrupole vibrational correction energies. The systematic behavior of the present correlation energies is in good agreement with that obtained from the projected generator coordinate method using the SLy4 Skyrme force although our values are systematically smaller. After including the dynamical correlation energies, the root- mean-square deviation predicted by the PC-PK1 for the 575 even-even nuclei masses is reduced from 2.58 MeV to 1.24 MeV.

Theoretical Studies of Proton Radioactivity

In the paper, we will discuss the most recent theoretical approaches developed by our group,to understand the mechanisms of decay by one proton emission, and the structure and shape of exotic nuclei at the limits of stability.