Charge-Changing Cross Sections for Mirror Nuclear Pair ²²Ne-²²Mg

To elucidate the structure of neutron-rich nuclei and neutron stars, it is crucial to determine the density derivative of the symmetry energy, represented by the parameter L, in the equation of state for asymmetric nuclear matter. This parameter L can be determined by the neutron skin thickness.

In this study, we measured the charge-changing cross-sections for mirror nuclei pair, ²²Ne-²²Mg. If complete charge symmetry holds between mirror nuclei, it is possible to derive the neutron distribution radius from the proton distribution radius of the mirror nucleus and obtain the thickness of the neutron skin.

The experiment was carried out at the Heavy Ion Medical Accelerator in Chiba. An ²⁷Al beam with an energy of 300 MeV/u impinged onto a Be target to produce the secondary beams. By utilizing Bρ, time-of-flight (TOF), and energy loss (△E) technique, we separated ²²Ne and ²²Mg beams with an energy of 150 MeV/u. Subsequently, these secondary beams impinged onto C and H targets, and the charge-changing cross-sections were measured using the transmission method by observing the attenuation of particles with the same atomic number.

I am going to present the results of our experimental study, which provides insights into neutron skin thickness through charge-changing cross-section measurements.