The multinucleon transfer (MNT) reaction approach was successfully employed for the first time to measure the isomeric ratios (IRs) of Po isomer (25/2) and its ground state (9/2) at the IGISOL facility using a 945 MeV Xe beam impinged on Bi and Pb targets. The dominant production of isomers compared to the corresponding ground states was consistently revealed in the -decay spectra. Deduced IR of Po populated through the Xe+Pb reaction was found to have an enhancement of ≈1.8-times than that observed for the Xe+Bi. State-of-the-art Langevin-type model calculations have been utilized to estimate the spin distribution of an MNT residue. The computations qualitatively corroborate with the considerable increase in the IRs of Po produced from Xe+Pb compared to Xe+Bi. Theoretical investigations indicate a weak dependence of target spin on the IRs. The enhancement of the Po isomer in the Xe+Pb over Xe+Bi can be attributed to the different proton ()-transfer production routes. Estimations demonstrate an increment in the angular momentum transfer, favorable for isomer production, with increasing projectile energy. Comparative analysis reveals the two entrance channel parameters, projectile mass and -transfer channels, strongly influencing the population of the high-spin isomer of Po (25/2). This letter reports the first experimental and theoretical study on the IRs of nuclei formed from two different -transfer channels via two independent MNT reactions.

中文翻译：

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多核子转移反应中异构比的首次研究：入口通道对自旋分布的影响


首次成功采用多核子转移 (MNT) 反应方法在 IGISOL 设施中使用 945 MeV Xe 束测量 Po 异构体 (25/2) 及其基态 (9/2) 的异构比 (IR)撞击 Bi 和 Pb 目标。与相应的基态相比，异构体的主要产生在β衰变光谱中得到了一致的揭示。发现通过 Xe+Pb 反应填充的 Po 的推导 IR 比 Xe+Bi 观察到的增强约 1.8 倍。最先进的 Langevin 型模型计算已用于估计 MNT 残基的自旋分布。计算定性地证实了 Xe+Pb 产生的 Po 的 IR 与 Xe+Bi 相比显着增加。理论研究表明目标自旋对红外光谱的依赖性较弱。 Xe+Pb 中的 Po 异构体比 Xe+Bi 中的增强可归因于不同的质子 ()-转移生产路线。估计表明，随着弹丸能量的增加，角动量传递会增加，有利于异构体的产生。比较分析揭示了两个入口通道参数，弹丸质量和-传输通道，强烈影响Po的高自旋异构体的数量（25/2）。这封信报告了对通过两个独立的 MNT 反应由两个不同的转移通道形成的原子核的 IR 的首次实验和理论研究。