Saito Haruo, Hyodo Toshio
Institute of Physics, Graduate School of Arts and Sciences, University of Tokyo, 3-8-1, Komaba, Tokyo, 153-8902, Japan.
Phys Rev Lett. 2006 Dec 22;97(25):253402. doi: 10.1103/PhysRevLett.97.253402. Epub 2006 Dec 19.
Spin-orbit interaction of positronium (Ps) with the surrounding atoms, predicted by Mitroy and Novikov [Phys. Rev. Lett. 90, 183202 (2003)], has been detected experimentally. We have found that the lifetime of the magnetically unperturbed ortho-Ps in Xe gas of 1 atm decreases significantly when a magnetic field of 1.0 T is applied. This decrease is attributed to the Ps spin conversion caused by spin-orbit interaction during Ps-Xe collision. The annihilation cross section of ortho-Ps due to this interaction has been determined to be 3 times as large as that expected by Mitroy and Novikov.
米特罗伊和诺维科夫[《物理评论快报》90, 183202 (2003)]预测的正电子素（Ps）与周围原子的自旋-轨道相互作用已通过实验检测到。我们发现，当施加1.0 T的磁场时，1个大气压的氙气中磁未受扰的正电子素的寿命会显著降低。这种降低归因于正电子素-氙碰撞过程中自旋-轨道相互作用引起的正电子素自旋转换。由于这种相互作用，正电子素的湮灭截面已被确定为米特罗伊和诺维科夫预期值的3倍。
