Correa C E, Correa J R, Ordonez C A
Department of Physics, University of North Texas, Denton, Texas 76203, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2005 Oct;72(4 Pt 2):046406. doi: 10.1103/PhysRevE.72.046406. Epub 2005 Oct 28.
The classical trajectory of an initially unbound positron within the electric field of an antiproton and a uniform magnetic field is simulated in three dimensions. Several simulations are run incorporating experimental parameters used for antihydrogen production, which has been achieved by two different groups [M. Amoretti, Nature (London) 419, 456 (2002); G. Gabrielse, Phys. Rev. Lett. 89, 213401 (2002)]. The simulations indicate that temporary bound states of antihydrogen can form at positive energies, where the energy of the system is defined to be zero when the positron and antiproton are at rest with infinite separation. Such quasibound states, which form only when the magnetic field is present, are typically smaller than in a dimension perpendicular to the magnetic field. An analytical model is developed for a formation cross section, and it is found that quasibound states may form more frequently than stable Rydberg states.
在三维空间中模拟了初始未束缚的正电子在反质子电场和均匀磁场中的经典轨迹。结合用于产生反氢的实验参数进行了多次模拟，反氢的产生已由两个不同的研究小组实现[M. 阿莫雷蒂，《自然》（伦敦）419, 456 (2002)；G. 加布里埃尔塞，《物理评论快报》89, 213401 (2002)]。模拟表明，反氢的临时束缚态可以在正能量下形成，当正电子和反质子静止且相距无限远时，系统的能量被定义为零。这种仅在磁场存在时形成的准束缚态，在垂直于磁场的维度上通常比稳定的里德堡态小。针对形成截面建立了一个解析模型，发现准束缚态可能比稳定的里德堡态更频繁地形成。
