添加的内容 删除的内容
(修改自此处;原许可:CC BY-SA 3.0[网站升级迁移]) |
小 (机器人:清理不当的来源、移除无用的模板参数;整理源码) |
||
(未显示2个用户的4个中间版本) | |||
第1行: | 第1行: | ||
{{noteTA|G1=物理 |
{{noteTA|G1=物理学}} |
||
''' |
'''轴子'''(axion)是一种假想的[[亚原子粒子]],大约是1970年代为了解決[[CP破坏|CP守恒]]问题所提出的一个假想粒子,1977年的{{le|皮塞-奎恩理论|Peccei–Quinn theory}}(Peccei–Quinn theory)首先提到這个概念。目前[[意大利]]{{link-it|国立核子物理研究所|Istituto nazionale di fisica nucleare}}(Istituto Nazionale di Fisica Nucleare)的{{le|PVLAS探测器|PVLAS}}正在不停努力的尋找它。 |
||
== 性 |
== 性质 == |
||
理 |
理论預测轴子的[[质量]]极微小,只有10<sup>−6</sup>到10<sup>−2</sup>[[电子伏特|eV]]([[电子]]的五千亿分之一到五千万分之一),而且[[电荷]]和[[自旋]]都是零。轴子曾被认为是[[暗物质]]的组成部分之一,但近年来一些学者却将轴子从暗物质粒子的候选者中排除了。<ref>[http://www.sciencedirect.com/science/article/pii/S2212686414000156 Direct detection searches for axion dark matter]</ref><ref>[http://tech.huanqiu.com/discovery/2016-04/8820485.html 科学家排除轴子是暗物质粒子的候选者]</ref> |
||
== 探 |
== 探测 == |
||
目前探 |
目前探轴子的方法有两种。其中一种是利用[[意大利]]的PVLAS探测器,其原理是用一束线[[偏振]]的[[雷射]]照射到一个具有强[[磁场]]的[[真空]]中,然后观测雷射穿越磁场后的偏振變化。<ref name="sciscape">{{cite web |url=http://www.sciscape.org/news_detail.php?news_id=2271 |title=存档副本 |accessdate=2008-09-04 }}</ref>而且已经探到10<sup>−12</sup> [[弧度|rad]]的變化,但有可能只是儀器本身的问题。<ref name="sciscape"/>另一种方法是每当十月左右[[类星体]][[3C 279]]与[[太阳]]和[[地球]]排成一直线的时候,3C 279发出的[[光子]]通过太阳,而這些光子可能会被太阳的[[磁场]]转成轴子,并且又變回光子,而探测這些光子可以帮助我们了解轴子的是否存在<ref>[http://iopscience.iop.org/article/10.1088/1475-7516/2011/11/020/meta;jsessionid=5EED222869EEC90213E7FCDEBAB28600.c4.iopscience.cld.iop.org Axion-like particle imprint in cosmological very-high-energy sources]</ref>。 |
||
== 2014年的新发现 == |
== 2014年的新发现 == |
||
第15行: | 第15行: | ||
{{Reflist}} |
{{Reflist}} |
||
== |
== 链接 == |
||
* [http://physics.aps.org/articles/v1/36 November 24, 2008 article in APS Physics] |
* [http://physics.aps.org/articles/v1/36 November 24, 2008 article in APS Physics] |
||
* [http://www.newscientist.com/channel/fundamentals/dn11041-lastgasp-test-could-reveal-dark-matter.html January 28, 2007 news article by newscientist.com] |
* [http://www.newscientist.com/channel/fundamentals/dn11041-lastgasp-test-could-reveal-dark-matter.html January 28, 2007 news article by newscientist.com] |
||
* [ |
* [http://www.physorg.com/news84633896.html December 06, 2006 news article by physorg.com] |
||
* [http://sciam.com/article.cfm?chanID=sa004&articleID=0006BA85-FC58-1492-BAAC83414B7F0000&ref=nature July 17, 2006 news article from Scientific American] |
* [http://sciam.com/article.cfm?chanID=sa004&articleID=0006BA85-FC58-1492-BAAC83414B7F0000&ref=nature July 17, 2006 news article from Scientific American] |
||
* [http://physicsweb.org/articles/news/10/3/19/1 March 27, 2006 news article by PhysicsWeb.org] |
* [http://physicsweb.org/articles/news/10/3/19/1 March 27, 2006 news article by PhysicsWeb.org] |
||
* [http://physicsweb.org/articles/news/8/11/13/1 November 24, 2004 news article by PhysicsWeb.org] |
* [http://physicsweb.org/articles/news/8/11/13/1 November 24, 2004 news article by PhysicsWeb.org] |
||
* [http://cern.ch/cast CAST Experiment] |
* [http://cern.ch/cast CAST Experiment] |
||
* [ |
* [http://cast.mppmu.mpg.de/ CAST at MPI/MPE] |
||
* [ |
* [http://astropp.physik.tu-darmstadt.de/cast/ CAST at University of Technology Darmstadt] |
||
* [http://www.phys.washington.edu/groups/admx/home.html ADMX at University of Washington] |
* [http://www.phys.washington.edu/groups/admx/home.html ADMX at University of Washington] |
||