The evolution of the hot and rotating $^{43}\mathrm{Sc}$ nucleus to a highly deformed shape has been studied by measuring the high-energy $\ensuremath{\gamma}$ rays from the decay of the giant dipole resonance. The compound nucleus was populated at two initial excitation energies and average angular momenta of $\ensuremath{\approx}26$ and $31\ensuremath{\hbar}$ by using $^{16}\mathrm{O}$ beam of energies ${E}_{\mathrm{lab}}$ = 120 and 142 MeV, respectively. The evaporated neutron energy spectra have been measured for proper determination of nuclear level density. The angular momentum has been determined by measuring the low-energy $\ensuremath{\gamma}$-ray multiplicities. The high-energy $\ensuremath{\gamma}$-ray and neutron spectra were analyzed simultaneously. At $\ensuremath{\langle}J\ensuremath{\rangle}\ensuremath{\approx}26\ensuremath{\hbar}$ a near-oblate shape is observed, whereas at $\ensuremath{\langle}J\ensuremath{\rangle}\ensuremath{\approx}31\ensuremath{\hbar}$ a sharp peak is observed at ${E}_{\ensuremath{\gamma}}\ensuremath{\approx}10\phantom{\rule{0.28em}{0ex}}\mathrm{MeV}$ pointing towards the transition to the Jacobi shape with quadruple deformation parameter $\ensuremath{\beta}\ensuremath{\approx}0.7$. The results have been corroborated by the theoretical calculations based on the rotating liquid drop model framework.

中文翻译：

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探测热旋转 Sc43 中的雅可比形状转变

通过测量来自巨偶极共振衰变的高能 $\ensuremath{\gamma}$ 射线，研究了热旋转的 $^{43}\mathrm{Sc}$ 核向高度变形形状的演化. 通过使用 $^{16}\mathrm{O}$ 能量束 $\ensuremath{\a​​pprox}26$ 和 $31\ensuremath{\hbar}$ 的两个初始激发能量和平均角动量填充复合核{E}_{\mathrm{lab}}$ = 120 和 142 MeV，分别。已测量蒸发中子能谱以正确确定核能级密度。角动量是通过测量低能量 $\ensuremath{\gamma}$ 射线多重性来确定的。同时分析了高能 $\ensuremath{\gamma}$ 射线和中子光谱。在 $\ensuremath{\langle}J\ensuremath{\rangle}\ensuremath{\a​​pprox}26\ensuremath{\hbar}$ 处观察到一个接近扁圆的形状，而在 $\ensuremath{\langle}J\ensuremath{ \rangle}\ensuremath{\a​​pprox}31\ensuremath{\hbar}$ 在 ${E}_{\ensuremath{\gamma}}\ensuremath{\a​​pprox}10\phantom{\rule{0.28 处观察到一个尖峰em}{0ex}}\mathrm{MeV}$ 指向具有四重变形参数 $\ensuremath{\beta}\ensuremath{\a​​pprox}0.7$ 的雅可比形状的过渡。结果已通过基于旋转液滴模型框架的理论计算得到证实。28em}{0ex}}\mathrm{MeV}$ 指向具有四重变形参数 $\ensuremath{\beta}\ensuremath{\a​​pprox}0.7$ 的雅可比形状的过渡。结果已通过基于旋转液滴模型框架的理论计算得到证实。28em}{0ex}}\mathrm{MeV}$ 指向具有四重变形参数 $\ensuremath{\beta}\ensuremath{\a​​pprox}0.7$ 的雅可比形状的过渡。结果已通过基于旋转液滴模型框架的理论计算得到证实。