While Josephson-like junctions, transiently established in heavy-ion collisions (${\tau }_{\mathrm{coll}}\approx {10}^{-21}\mathrm{s}$) between superfluid nuclei–through which Cooper-pair tunneling ($Q$-value $Q_{2n}$) proceeds mainly in terms of successive transfer of entangled nucleons–is deprived from the macroscopic aspects of a supercurrent, it displays many of the special effects associated with spontaneous symmetry breaking in gauge space (BCS condensation), which can be studied in terms of individual quantum states and of tunneling of single Cooper pairs. From the results of studies of one- and two-neutron transfer reactions carried out at energies below the Coulomb barrier we estimate the value of the mean-square radius (correlation length) of the nuclear Cooper pair. A quantity related to the largest distance of closest approach for which the absolute two-nucleon tunneling cross section is of the order of the single-particle one. Furthermore, emission of $\gamma$ rays of (Josephson) frequency ${\nu }_J=Q_{2n}/h$ distributed over an energy range $\hslash /{\tau }_{\mathrm{coll}}$ is predicted.

中文翻译：

---

γ射线在核库珀对隧穿中的量子纠缠

类似于约瑟夫森的结，在重离子碰撞中短暂建立（${\tau }_{\mathrm{柯尔}}\approx {10}^{-\mathrm{21岁}}\mathrm{s}$）之间的超流体核–库珀对隧穿（$问$-价值 ${问}_{\mathrm{2个}ñ}$）的进展主要是从纠缠核子的连续转移开始-从超电流的宏观方面被剥夺了，它显示出许多与尺度空间自发对称破坏有关的特殊效应（BCS凝聚），可以从个体角度进行研究。量子态和单个库珀对的隧穿。根据在库仑势垒以下的能量进行的一次和两次中子转移反应的研究结果，我们估计了核库珀对的均方半径（相关长度）的值。与最接近方法的最大距离有关的数量，其绝对两个核子隧穿截面的大小约为单粒子一个。此外，排放$\gamma$ （约瑟夫森）频率的射线 ${\nu }_{Ĵ}={问}_{\mathrm{2个}ñ}/H$ 分布在能量范围内 $\hslash /{\tau }_{\mathrm{柯尔}}$ 被预测。