An experimental study on the temperature ($T$) dependence of giant dipole resonance (GDR) width was performed for the medium mass nucleus ${}^{74}\mathrm{Kr}$ in the range of $T\approx 2–2.5$ MeV at an average angular momentum of $26\hslash$ using the ${}^{16}\mathrm{O}+{}^{58}\mathrm{Ni}$ fusion reaction. The emitted high-energy $\gamma$ rays and evaporated neutrons were measured in coincidence with low-energy discrete $\gamma$-ray multiplicities. The GDR parameters, nuclear level density parameter, and nuclear temperature were determined by the statistical model analysis of the high-energy $\gamma$-ray spectra as well as evaporated neutron spectra. The measured GDR width is found to increase monotonically with temperature, in contradiction with the recent observation of the width saturation in ${}^{88}\mathrm{Mo}$. Comparisons of the measured data with predictions of the adiabatic thermal shape fluctuation model and its refined version, the critical temperature included fluctuation model, are presented and discussed.

中文翻译：

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中等质量原子核中没有巨偶极共振宽度饱和的特征

温度的实验研究（$吨$) 对中等质量核进行了巨偶极共振 (GDR) 宽度的依赖性 ${}^{74}氪$ 在范围内 $吨\approx 2——2.5$ MeV 的平均角动量为 $26\hslash$ 使用 ${}^{16}\mathrm{哦}+{}^{58}你$聚变反应。发射的高能$\gamma$ 射线和蒸发中子的测量与低能离散 $\gamma$-射线多重性。GDR参数、核能级密度参数和核温度由高能的统计模型分析确定。$\gamma$射线光谱以及蒸发中子光谱。发现测量的 GDR 宽度随温度单调增加，这与最近观察到的宽度饱和${}^{88}莫$. 介绍和讨论了测量数据与绝热热形状波动模型及其改进版本、临界温度包括波动模型的预测的比较。