精确且不依赖模型地测定原子核的中子分布半径$R_{\ m n}$以及由此得到的中子皮厚度$R_{\ m skin}$，在核物理、粒子物理和天体物理学中具有根本重要性，但在地面实验室中仍是一大挑战。我们提出，银河系内邻近的核心坍缩超新星（CCSN）可能产生具有前所未有的高光度的中微子流，为通过相干弹性中微子-原子核散射（CE$ν$NS）测定$R_{\ m n}$和$R_{\ m skin}$提供了绝佳机会。我们评估了借助RES-NOVA项目（该项目旨在利用考古铅基低温探测器阵列搜寻CCSN中微子），通过邻近CCSN中微子的CE$ν$NS测定铅（Pb）的$R_{\ m n}$的潜力。我们发现，在CCSN爆炸发生在距地球约1千秒差距（kpc）的最乐观情况下，RES-NOVA可实现铅的$R_{\ m n}$约0.1%的极限精度（对应$R_{\ m skin}$约0.006飞米（fm））。
英文摘要：
A precise and model-independent determination of the neutron distribution radius $R_{\rm n}$ and thus the neutron skin thickness $R_{\rm skin}$ of atomic nuclei is of fundamental importance in nuclear physics, particle physics and astrophysics but remains a big challenge in terrestrial labs. We argue that the nearby core-collapse supernova (CCSN) in our Galaxy may render a neutrino flux with unprecedentedly high luminosity, offering perfect opportunity to determine the $R_{\rm n}$ and $R_{\rm skin}$ through the coherent elastic neutrino-nucleus scattering (CE$ν$NS). We evaluate the potential of determining the $R_{\rm n}$ of lead (Pb) via CE$ν$NS with the nearby CCSN neutrinos in the RES-NOVA project which is designed to hunt CCSN neutrinos using an array of archaeological Pb based cryogenic detectors. We find that an ultimate precision of $\sim 0.1 \%$ for the $R_{\rm n}$ ($\sim 0.006$ fm for the $R_{\rm skin}$) of Pb can be achieved via RES-NOVA in the most optimistic case that the CCSN explosion were to occur at a distance of $\sim 1$ kpc from the Earth.
The complex nature of the nuclear forces generates a broad range and diversity of observational phenomena. Heavy nuclei, though orders of magnitude less massive than neutron stars, are governed by the same underlying physics, which is enshrined in the nuclear equation of state. Heavy nuclei are expected to develop a neutron-rich skin where many neutrons collect near the surface. Such a skin thickness is strongly sensitive to the poorly-known density dependence of the symmetry energy near saturation density. An accurate and model-independent determination of the neutron-skin thickness of heavy …
The neutron density distributions and neutron skin thicknesses in $^{40,48}$Ca are determined from the angular distributions of the cross sections and analyzing powers of polarized proton elastic scattering at $E_p = 295$ MeV. Based on the framework of the relativistic impulse approximation with the density-dependent effective $NN$ interaction, the experimental data is successfully analyzed, providing precise information of neutron and proton density profiles of $^{40,48}$Ca with small uncertainties. The extracted neutron and proton density distributions give neutron skin thicknesses in $^{40,…
Neutron skin impurity from Coulomb core polarization in $^{208}\text{Pb}$: Insights from PREX-II and validation via the $(^{3}\text{He}, t)$ isobaric analog state reaction
Heavy atomic nuclei have an excess of neutrons over protons, which leads to the formation of a neutron skin whose thickness is sensitive to details of the nuclear force. This links atomic nuclei to properties of neutron stars, thereby relating objects that differ in size by orders of magnitude. The nucleus ${}^{208}$Pb is of particular interest because it exhibits a simple structure and is experimentally accessible. However, computing such a heavy nucleus has been out of reach for ab initio theory. By combining advances in quantum many-body methods, statistical tools, and emulator technology, …
Recent experimental and ab initio theory investigations of the 208Pb neutron skin thickness are sufficiently precise to inform the neutron star equation of state. In particular, the strong correlation between the 208Pb neutron skin thickness and the pressure of neutron matter at normal nuclear densities leads to modified predictions for the radii, tidal deformabilities, and moments of inertia of typical 1.4 solar-mass neutron stars. In the present work, we study the relative impact of these recent analyses of the 208Pb neutron skin thickness on bulk properties of neutron stars within a Bayesia…
Recent precise parity-violating electron scattering experiments on $^{48}$Ca (CREX) and $^{208}$Pb (PREX-II) provide a new insight on the formation of neutron skin in nuclei. Within the energy density functional (EDF) framework, we investigate the implications of CREX and PREX-II data on nuclear matter symmetry energy and isovector properties of finite nuclei: neutron skin thickness and dipole polarizability. The weak-charge form factors from the CREX and PREX-II experiments are employed directly in constraining the relativistic density-dependent point coupling EDFs. The EDF established with t…
Using the new results on coherent elastic neutrino-nucleus scattering data in cesium-iodide provided by the COHERENT experiment, we determine a new measurement of the average neutron rms radius of $^{133}\text{Cs}$ and $^{127}\text{I}$. In combination with the atomic parity violation (APV) experimental result, we derive the most precise measurement of the neutron rms radii of $^{133}\text{Cs}$ and $^{127}\text{I}$, disentangling for the first time the contributions of the two nuclei. By exploiting these measurements we determine the corresponding neutron skin values for $^{133}\text{Cs}$ and $…
