كيف تغيّر سماكة معطف النيوترونات اصطدام النوى سريع

الملخص الأصلي

كما كتبه المؤلفون، بالإنجليزية arXiv:2608.13935v1

The initial nuclear geometry of colliding nuclei, manifested in proton and neutron density profiles, plays a key role in determining final-state effects in high-energy heavy-ion collisions. We study $${^{96}\text{Ru}}+{^{96}\text{Ru}}$$ and $${^{96}\text{Zr}}+{^{96}\text{Zr}}$$ collisions at $$\sqrt{s_{\text{NN}}}=200$$ GeV incorporating an isospin-dependent Woods-Saxon distribution to account for neutron-skin effects in the UrQMD model. By systematically scanning the proton surface diffuseness parameter $$a_{\text{p,Zr}}$$ of the $$^{96}\text{Zr}$$ nucleus and performing a $$\chi^2$$ analysis by comparing with STAR experimental data, we extract the relative neutron-skin thickness difference $$0.278 \pm 0.018$$ fm between the two isobaric systems using the net-charge yield difference $$\Delta Q$$. We further show that the neutron-skin effect evidently modifies the baryon-to-charge transport ratio $$R_{B/Q}=\langle B \rangle/\Delta Q \times \Delta Z/A$$, and substantially influences the observed $$R_{B/Q}>1$$ behavior in central collisions. This work indicates that nuclear structure effects contribute non-negligibly to baryon transport observables without a baryon junction hypothesis, and underscores the importance of precise initial-state geometry constraints for exploring novel QCD phenomena in relativistic heavy-ion collisions.