Search for trapped antihydrogen
Search for trapped antihydrogen
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DOI：
10.1016/j.physletb.2010.11.004
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发表时间：
2011-01-10
影响因子：
4.4
通讯作者：
Yamazaki, Y.
中科院分区：
文献类型：
--
作者：
Andresen, G. B.;Ashkezari, M. D.;Yamazaki, Y.
本文介绍了在欧洲核子研究中心反质子减速器上用阿尔法反氢阱寻找被囚禁的反氢原子的实验结果。被捕获的反质子和正电子等离子体的温度，大小和密度的灵敏诊断已经开发出来，这反过来又允许技术的发展，以精确和可重复地控制初始实验参数。位置敏感的湮没顶点探测器的使用，连同可控淬火超导磁最小陷阱的能力，使我们能够进行高灵敏度和低背景搜索被困的合成反氢原子。我们的目标是确定反氢原子在陷阱中保持至少130毫秒后在大约30毫秒内被释放的湮灭。在2009年进行了为期三周的实验后，将10（7）个反质子与1.3 × 10（9）个正电子混合，产生6 × 105个反氢原子，我们已经确定了六个反质子湮灭事件，这与被困反氢的释放是一致的。宇宙射线背景估计贡献0.14个计数，与这一观测结果不相容，显着性为5.6西格玛。大量的模拟预测，另一种湮灭源，即被镜面捕获的反质子的逃逸，是极不可能的，尽管这种可能性还没有被实验排除。(C)2010 Elsevier B.V.保留所有权利。
We present the results of an experiment to search for trapped antihydrogen atoms with the ALPHA antihydrogen trap at the CERN Antiproton Decelerator. Sensitive diagnostics of the temperatures, sizes, and densities of the trapped antiproton and positron plasmas have been developed, which in turn permitted development of techniques to precisely and reproducibly control the initial experimental parameters. The use of a position-sensitive annihilation vertex detector, together with the capability of controllably quenching the superconducting magnetic minimum trap, enabled us to carry out a high-sensitivity and low-background search for trapped synthesised antihydrogen atoms. We aim to identify the annihilations of antihydrogen atoms held for at least 130 ms in the trap before being released over similar to 30 ms. After a three-week experimental run in 2009 involving mixing of 10(7) antiprotons with 1.3 x 10(9) positrons to produce 6 x 105 antihydrogen atoms, we have identified six antiproton annihilation events that are consistent with the release of trapped antihydrogen. The cosmic ray background, estimated to contribute 0.14 counts, is incompatible with this observation at a significance of 5.6 sigma. Extensive simulations predict that an alternative source of annihilations, the escape of mirror-trapped antiprotons, is highly unlikely, though this possibility has not yet been ruled out experimentally. (C) 2010 Elsevier B.V. All rights reserved.