The particular conditions for the recent measurement of 91Zr(n,α)88Sr reaction cross sections at incident energies below 5.3 MeV [Phys. Rev. C 106, 064602 (2022)] as well as a previous detailed analysis of other reaction channels involving neutrons incident on 91Zr, using a consistent set of model parameters, have two main advantages. First, the close agreement between the calculated and experimentally obtained data for the incident energy associated mainly with the ground-state activation provides strong support for the α-particle optical potential involved in this analysis. Second, a further underestimation of the cross section is observed around the energy corresponding to the isoscalar giant quadrupole resonance (ISGQR), beyond any model parameter uncertainty. This underestimation is consistent with previous observations of ISGQR-like α-particle decay of excited nuclei for neutron-induced reactions in the mass range 54≤A≤98. To phenomenologically identify the ISGQR-like behavior, a comparison is made between their strengths and the ISGQR strengths measured through the (γ,α) reaction and inelastic scattering of 3He and α-particles. Additionally, an isotope effect, possibly related to the decrease in Q-value with the target-nuclei asymmetry parameter, supports the observation of a low energy-weighted sum rule (EWSR) fraction for the ISGQR-like strength function in the excited nucleus 92Zr.

中文翻译：

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中子诱导的α粒子发射中的巨大四极共振？


最近在入射能量低于 5.3 MeV 的情况下测量 91Zr（n，α）88Sr 反应截面的特殊条件 [Phys. Rev. C 106， 064602 （2022）] 以及之前使用一组一致的模型参数对涉及入射 91Zr 的中子的其他反应通道的详细分析，具有两个主要优点。首先，主要与基态激活相关的入射能量的计算数据和实验获得的数据之间的紧密一致性为该分析中涉及的α粒子光势提供了强有力的支持。其次，在对应于等标量巨型四极杆共振 （ISGQR） 的能量周围观察到横截面的进一步低估，超出了任何模型参数的不确定性。这种低估与之前观察到的质量范围内 54≤A≤98 的中子诱导反应中激发原子核的 ISGQR 样 α 粒子衰变一致。为了从现象学上鉴定 ISGQR 样行为，将它们的强度与通过 3He 和 α 粒子的 （γ，α） 反应和非弹性散射测量的 ISGQR 强度进行了比较。此外，可能与目标-核不对称参数的 Q 值降低有关的同位素效应支持在激发核 92Zr 中观察 ISGQR 样强度函数的低能量加权和规则 （EWSR） 分数。