“Six thousand billion of them are going through your body every second.” That’s physicist Lawrence Krauss on neutrinos, on the June 15th weekly Science Talk podcast. “Neutrinos are the lightest elementary particles we know of. The name comes from the fact that they had to be neutral because we couldn’t see them in detectors. But they had to be light. So Enrico Fermi called them ‘a little neutron,’ in Italian is neutrino. So they were baby neutrons, which were the only other neutral particles at the time that were known.”
“每秒鐘會有六萬億個中微子穿過你的身體。”這是物理學家勞倫斯·克勞斯在6月15日的每周科學講話節目中提出的有關中微子的論述。“中微子是目前為止我們所知的最輕的基本粒子。由于我們在探測器中觀察不到它們，它們一定是中性的，這就是它們名字的由來。并且它們又很輕，所以恩里科·費爾米稱它們為‘小中子’，意大利人則叫它中微子。因此，它們是很小的中子，從被發現起就是除了中子以外唯一的中性粒子。”
Now astrophysicists [Shaun Thomas, Ofer Lahav and Filipe Abdalla] have put a best-guess upper limit on the mass of the neutrino. The research is being reported this week at the Weizmann UK conference at University College London and will appear in an upcoming issue of Physical Review Letters.
目前，天體物理學家們已經對中微子的質量上限做出了最好的測定。研究成果將于本周在英國倫敦大學的英倫魏茨曼會議上報導，并將發表在下一期的《物理評論快報》上。
The work took advantage of the huge 3-D galaxy map called Mega Z. Because there are so many neutrinos, their tiny masses add up to influence the overall distribution of galaxies. And the researchers say the galactic map depends on a neutrino’s mass being no more than 0.28 electron volts, less than a billionth of the mass of an atom of hydrogen, the lightest element. “These are the most interesting particles in nature.”
此研究利用了巨大的3D星系地圖Mega Z。由于宇宙中有巨量的中微子，盡管其質量極小，但合起來就足以影響到星系的分布。并且，研究人員說，從宇宙星系分布圖來推測，中微子的質量最多不超過 0.28電子伏特，比氫原子質量的十億分之一還要輕，可以說是最輕的微粒了。“事實上，它們是最有趣的粒子。”
來源:可可英語 http://www.ccdyzl.cn/hangye/201201/167426.shtml
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