8–13 Sept 2025
Integrated Innovation Building (IIB), RIKEN Kobe Campus
Asia/Tokyo timezone
Registration is closed. We look forward to seeing you in Kobe!

Investigation of the neutron-proton effective mass splitting via heavy ion collisions

10 Sept 2025, 09:50
30m
Auditorium (8F) (Integrated Innovation Building (IIB), RIKEN Kobe Campus)

Auditorium (8F)

Integrated Innovation Building (IIB), RIKEN Kobe Campus

Minatojima-minamimachi 6-7-1, Kobe, Japan
2. Heavy-ion collision experiments and transport model simulations NuSym Scientific Session

Speaker

Yingxun Zhang (China Institute of Atomic Energy)

Description

In my talk, I will first mention our efforts on the improvements of the transport models after the TMEP, such as the consistency of the initialization, extended Skyrme momentum dependent interaction, a novel Pauli blocking algorithm, and so on. Then, I will discuss the recent effort on understanding the constraints of the neutron-proton effective mass splitting (Δm_np^) via HICs. We find a strong correlation between the slope of the neutron-to-proton yield ratio with respect to the kinetic energy (i.e., Sn/p) and Δm_np^, with correlation coefficients exceeding 0.80. For the 124Sn +124 Sn system, this correlation reaches 0.928. By comparing theoretical predictions with experimental data, we reveal a novel dependence of the neutron-proton effective mass splitting on momentum: at low kinetic energies, the data favor m_n^>m_p^ which is consistent with the nucleon-nucleus scattering analysis, while at high kinetic energies, they favor m_n^<m_p^ which is an extended understanding of effective mass splitting at high kinetic energy region. This finding provides the first direct evidence that the momentum-dependent symmetry potential likely decreases initially and then increases with momentum.

Presentation Style Invited Speaker

Author

Yingxun Zhang (China Institute of Atomic Energy)

Presentation materials