Barbosa Alessandra Souza, Pastega Diego F, Bettega Márcio H F
Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-990 Curitiba, Paraná, Brazil.
J Chem Phys. 2015 Dec 28;143(24):244316. doi: 10.1063/1.4938427.
This work reports elastic integral and differential cross sections for positron collisions with pyrimidine, for energies up to 20 eV. The cross sections were computed with the Schwinger multichannel method in the static plus polarization approximation. We also employed the Born closure procedure to account for the long range potential due to the permanent dipole moment of the molecule. Our results are compared with the experimental total cross section of Zecca et al. [J. Phys. B 43, 215204 (2010)], the experimental grand-total, quasi-elastic integral and differential cross section of Palihawadana et al. [Phys. Rev. A 88, 12717 (2013)]. We also compare our results with theoretical integral and differential cross sections obtained by Sanz et al. [Phys. Rev. A 88, 62704 (2013)] with the R-matrix and the independent atom model with screening-corrected additivity rule methods, and with the results computed by Franz and Gianturco [Phys. Rev. A 88, 042711 (2013)] using model correlation-polarization potentials. The agreement between the theory and the experiment is encouraging.
这项工作报道了能量高达20电子伏特时正电子与嘧啶碰撞的弹性积分截面和微分截面。这些截面是在静态加极化近似下用施温格多通道方法计算得到的。我们还采用了玻恩闭合程序来考虑由于分子的永久偶极矩而产生的长程势。我们的结果与泽卡等人[《物理学报B》43, 215204 (2010)]的实验总截面、帕利哈瓦达纳等人[《物理评论A》88, 12717 (2013)]的实验总截面、准弹性积分截面和微分截面进行了比较。我们还将我们的结果与桑兹等人[《物理评论A》88, 62704 (2013)]用R矩阵和具有屏蔽校正加和规则方法的独立原子模型得到的理论积分截面和微分截面，以及与弗兰兹和詹图尔科[《物理评论A》88, 042711 (2013)]使用模型相关极化势计算得到的结果进行了比较。理论与实验之间的一致性令人鼓舞。
