الرصاص بدلاً من الكربون: كيف نقيس النواة بدقة أكبر سريع

الملخص الأصلي

كما كتبه المؤلفون، بالإنجليزية arXiv:2608.14957v1

We found that a heavy target such as Pb is most suitable for determining the proton distribution radii of unstable nuclei through charge-changing cross-section ($$\sigma_\text{cc}$$) measurements. As a heavy ion probe, low-$$Z$$ targets are routinely used to determine nucleon distribution radii of unstable isotopes. This approach has recently been extended to study proton distribution radii from $$\sigma_\text{cc}$$ measurements. However, empirical scaling factors have to be introduced to apply the Glauber models. In the present work, we systematically investigated the scaling factor using 39 new $$\sigma_\text{cc}$$ data of 18 $$p$$-shell nuclei on hydrogen, carbon, silver, and lead targets at around 240 MeV/nucleon. Together with the existing data, we reveal a universal dependence of the scaling factor on both the masses of target nuclei and the separation energies of projectile nuclei. The scaling factors decrease with increasing target-nucleus mass and converge to 1 for the highest-$$Z$$ target, making the scaling unnecessary. We conclude that instead of a low-$$Z$$ target, employing a heavy target such as Pb in $$\sigma_\text{cc}$$ measurements is the best option to determine the proton distribution radii of unstable nuclei.