Speaker
Description
Introduction
The density dependence of nuclear symmetry energy is a key issue in nuclear physics and astrophysics, influencing the structure of neutron stars and the dynamics of supernovae.
The isovector reorientation (IVR) effect in polarized deuteron scattering provides a novel and sensitive probe to constrain the symmetry energy, especially at sub-saturation densities.
Objective
To demonstrate the feasibility of measuring the IVR effect using a polarized deuteron beam at the SAMURAI spectrometer (RIKEN).
To develop and validate methods for monitoring tensor polarization ($p_{z'z'}$, $p_{y'y'}$) of the deuteron beam.
Methodology
Beam and Setup:
Polarized deuteron beam (190 MeV/u) produced and monitored with a dedicated polarimeter.
Scattering on heavy targets ($^{124}$Sn, $^{208}$Pb) with detection of breakup protons (PDC) and neutrons (NEBULA).
Simulation:
Event generation with ImQMD transport model.
Detector response simulated using Geant4.
Key Observable:
$R = \frac{N(p_x^p > p_x^n)}{N(p_x^p < p_x^n)}$ quantifies the IVR effect and its sensitivity to the symmetry energy parameter $\gamma$.
Results
The IVR effect is clearly observed in simulations for both longitudinal and transverse tensor polarizations.
The observable $R$ shows strong sensitivity to the stiffness of the symmetry energy, especially in neutron-rich targets.
The proposed method enables precise monitoring of tensor polarization and robust extraction of symmetry energy information.
Conclusion & Impact
The study demonstrates the feasibility of using polarized deuteron scattering to probe the nuclear symmetry energy.
The results provide valuable constraints for nuclear structure and astrophysics, with implications for understanding neutron stars and supernovae.
| Presentation Style | Poster Presentation |
|---|