Competition between predissociative and radiative decays in the e(3)Sigma(+)(u) and d(3)Pi(-)(u) states of H-2 and D-2
Competition between predissociative and radiative decays in the e(3)Sigma(+)(u) and d(3)Pi(-)(u) states of H-2 and D-2
复制标题
H-2 和 D-2 的 e(3)Sigma( )(u) 和 d(3)Pi(-)(u) 态中预解离衰变和辐射衰变之间的竞争
DOI：
10.1103/physreva.60.4494
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发表时间：
1999
影响因子：
2.9
通讯作者：
A. Stolyarov
中科院分区：
文献类型：
--
作者：
T. Kiyoshima;S. Sato;S. O. Adamson;E. Pazyuk;A. Stolyarov
给出了氢分子和氘分子e3 <$u+和d3 <$u−态在较宽的振动v′和转动N′量子数范围内的实验和理论寿命τ v′ N′。寿命已被测量的延迟符合方法以下的电子碰撞激发从基态。通过详细的分析，估计级联效应对测得的寿命可以忽略不计。预解离率是根据费米黄金法则，基于绝热旋振波函数和径向耦合矩阵元B（R），对e3 <$u+<$b3 <$u+和d3 <$u− <$c3 <$u−相互作用态对进行估算的。两个激发态的辐射寿命由理论上的e3 u+− a3 g+和d3 u-a3 g+跃迁偶极矩函数d（R）和相关态的绝热旋振波函数计算。在量子亏损理论的框架下，通过直接从头计算得到了电子矩阵元B（R）和d（R）。采用基于全组态相互作用电子波函数的有限差分法和Sidis解析公式计算了从头算B（R）函数。在小的和中等的核间距的量子亏损矩阵元同意以及与他们的从头算对应。发现氢的e3 Σ u+（v '>~ 0）和d3 Π u-（v'>~ 4）态的预解离速率随着预解离能级v '值的增加而急剧增加，并且与辐射衰变速率一致。在氘的预解离效应是可以忽略不计的两个国家的研究，因此，他们的实验寿命对应的辐射衰变通道。理论辐射率和预离解率之和与e3 u+态的实验结果非常一致，但对d3 u−态的估计略高。本文还讨论了产生差异的原因，并提出了进一步改进的建议。
Experimental and theoretical lifetimes τ v′ N′ for e 3 Σ u+ and d 3 Π u− states of molecular hydrogen and deuterium are presented in a wide range of vibrational v′ and rotational N′ quantum numbers. Lifetimes have been measured by a delayed coincidence method following electron-impact excitation from the ground state. The cascade effects on the lifetimes measured were estimated to be negligible through a detailed analysis. Predissociative rates were estimated by the Fermi golden rule based on adiabatic rovibronic wave functions and radial coupling matrix elements B (R) for the e 3 Σ u+∼ b 3 Σ u+ and d 3 Π u−∼ c 3 Π u− pairs of interacting states. The radiative lifetimes of both excited states were evaluated by the theoretical e 3 Σ u+− a 3 Σ g+ and d 3 Π u–a 3 Σ g+ transition dipole moment functions d (R) and adiabatic rovibronic wave functions of the states involved. The electronic matrix elements B (R) and d (R) were obtained by direct ab initio calculations as well as within the framework of quantum defect theory. The ab initio B (R) functions were calculated by the finite-difference method and by the analytical Sidis formula, which were based on the full configuration-interaction electronic wave functions. At small and medium internuclear distances the quantum defect matrix elements agree well with their ab initio counterparts. The predissociative rates for both e 3 Σ u+(v′>~ 0) and d 3 Π u−(v′>~ 4) states of hydrogen were found to increase sharply as the v′ value of the predissociated level increases, and become compatible with the radiative decay rate. The predissociation effect in the deuterium was negligible for both states studied; hence their experimental lifetimes correspond to the radiative decay channel only. A sum of the theoretical radiative and predissociative rates was in good agreement with the experimental results for the e 3 Σ u+ state but slightly overestimated for the d 3 Π u− state. Reasons for the remaining discrepancies are discussed and suggestions for further improvements are given.