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Muons are fundamental particles in our universe that are essentially exactly the same as electrons, but heavier - 206.77 times heavier, to be precise.
μ介子是我们宇宙中的基本粒子，本质上与电子完全相同，但更重——准确地说，是电子的206.77倍。
Muons are super fascinating for a number of famous reasons, including (and this is definitely an incomplete list) as an experimental test of time dilation, as a catalyst making fusion possible at room temperature,
μ介子超级迷人的原因有很多，包括(这绝对是一个不完整的列表)作为时间膨胀的实验测试，作为使聚变在室温下成为可能的催化剂，
and that they can be used to make muonic versions of atoms, like muonic hydrogen (with a proton and a muon, instead of a proton and electron).
它们可以被用来制造介子版本的原子，比如介子氢(一个质子和一个介子，而不是一个质子和一个电子)。
But muons decay into an electron and some neutrinos after just a few microseconds on average, so they’re hard to store.
但μ介子平均在几微秒后就会衰变为电子和一些中微子，所以它们很难储存。
So to do experiments on muons, you need to have a source of muons on hand.
所以要在μ介子上做实验，你需要有一个现成的μ介子源。
A small number of muons are produced naturlly by cosmic rays striking our atmosphere, but one of the best ways of consistently and reliably making a lot of muons is with a particle accelerator.
少量的介子是由宇宙射线撞击我们的大气层而自然产生的，但持续且可靠地产生大量介子的最好方法之一是使用粒子加速器。
First, you take hydrogen and you strip off the electrons, leaving you with protons
首先，去掉氢原子和电子，剩下质子
(protons, as a reminder, are not fundamental particles- they consist of two up quarks and a down quark, stuck together by mutual attraction due to the strong nuclear force).
(提醒一下，质子不是基本粒子 --它们由两个上夸克和一个下夸克组成，由于强核力的相互吸引而粘在一起)。
Then you accelerate the protons really fast in an electric field (or a bunch of electric fields) and crash them into some other atomic nuclei, like lithium or carbon or whatever.
然后在电场(或一堆电场)中加速质子，使它们撞击到其他原子核，比如锂原子、碳原子或其他原子。
The energy of the collision creates a whole mess of particles that goes flying out, but most importantly for our purposes, it creates a particle called a pion
碰撞的能量产生了一大堆粒子，这些粒子会飞出去，但对我们来说，最重要的是，它产生了一种粒子，叫做介子
- either a pion with positive electric charge made from an up quark and an anti-down quark, or pion with negative electric charge made of a down and anti-up quark.
-由上夸克和反上夸克组成的带正电荷的介子，或由下夸克和反上夸克组成的带负电荷的介子。
If the pions keep traveling in a vacuum so that they don’t bump into anything else, they’ll spontaneously decay after about 26 nanoseconds, most frequently turning into a muon and a neutrino.
如果介子一直在真空中运动，这样它们就不会撞到其他任何东西，它们会在大约26纳秒后自发衰变，最常见的情况是变成介子和中微子。
Which you can use for fusion, or testing special relativity, or making cool cloud chamber esigns.
你可以用它来进行核聚变，或测试狭义相对论，或制作冷云室标志。
And that’s how you make muons - accelerate protons with enough energy that when they crash into other nuclei, the energy of the collision creates pions, which then decay into muons.
这就是产生介子的方法——用足够的能量加速质子，当它们碰撞到其他原子核时，碰撞的能量产生介子，然后衰变为介子。
Which, of course, after 2.2 microseconds on average, themselves spontaneously decay.
当然，平均在2.2微秒后，它们就会自发衰变。
