We study theoretically the resonance scattering of positronium (Ps) atoms by nitrogen molecules and compare it with resonance e –N 2 scattering in the Π g symmetry. The velocity positions of the Ps–N 2 resonances in Σ u , Π u , and Δ g symmetries are very close to the velocity position of the e –N 2 resonance which leads to the total Ps–N 2 cross section being very similar to the e –N 2 cross section when both are plotted as functions of the projectile velocity. However, in the Ps–N 2 case the resonances are much wider and their positions vary much slower with increasing internuclear separation than in the e –N 2 case. This makes the Ps-impact vibrational excitation cross section much smaller than the electron-impact vibrational excitation cross section, and no boomerang oscillations are observed in Ps–N 2

中文翻译：

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氮分子对正电子原子的共振散射

我们从理论上研究了氮分子对正电子（Ps）原子的共振散射，并将其与Πg对称的共振e -N 2散射进行了比较。Ps–N 2共振在Σu，Πu和Δg对称下的速度位置非常接近e –N 2共振的速度位置，这导致总的Ps–N 2横截面与两者的e –N 2横截面均作为弹丸速度的函数绘制。然而，在Ps–N 2情况下，与e –N 2情况相比，随着核间距的增加，共振范围更大，并且其位置变化要慢得多。这使得Ps冲击振动激发截面比电子冲击振动激发截面小得多，并且在Ps–N 2中没有观察到飞旋镖振荡。