Scientists on an experiment at the Large Hadron Collider(LHC) see massive W particles emerging from collisions with electromagnetic fields. How can this happen?
在大型強子對撞機(LHC)中，進行實驗的科學家們發現，來自具有電磁場之碰撞的大質量W粒子(也就是W玻色子，兩種被認為傳導弱力之大質量帶電的亞原子粒子之一。弱力是左右某些種類原子核中，放射性衰變的力)。這怎麼會發生？
The Large Hadron Collider plays with Albert Einstein’s famous equation, E = mc², to transform matter into energy and then back into different forms of matter. But on rare occasions, it can skip the first step and collide pure energy – in the form of electromagnetic waves.
大型強子對撞機戲弄了，愛因斯坦E = mc²的著名等式，將物質轉變成能量，然後轉變成不同形式的物質。不過，在諸多罕見情況下，這會跳過第一步，而以電磁波的形式，碰撞純粹的能量。
Last year, the ATLAS experiment at CERN’s LHC observed two photons, particles of light, ricocheting off one another and producing two new photons. This year, scientists have taken that research a step further and discovered photons merging and transforming into something even more interesting: W bosons, particles that carry the weak force, which governs nuclear decay.
去年(2019年)，在歐洲核子研究組織，大型強子對撞機的環狀大型強子對撞機設備(ATLAS：A Toroidal LHC Apparatus)實驗，觀測到兩個光子互相彈跳，且產生兩個新光子。今年，科學家們已經進一步進行那項研究，且發現光子合併及轉變成更引人關注之物：W玻色子，這是左右核衰變之傳導弱力的粒子。
The research doesn’t just illustrate the central concept governing processes inside the LHC: that energy and matter are two sides of the same coin. It also confirms that at high enough energies, forces that seem separate in our everyday lives – electromagnetism and the weak force – are united.
該項研究不僅闡明，LHC內部左右變化過程的主要概念：也就是，能量及物質是相同硬幣的兩個面。也證實，在夠高的能量下，在咱們日常生活中，似乎分開的力(電磁及弱力)是一體的。
If you try to replicate this photon-colliding experiment at home by crossing the beams of two laser pointers, you won’t be able to create new, massive particles. Instead, you’ll see the two beams combine to form an even brighter beam of light.
倘若在家中，試圖藉由交叉兩個雷射指示器的光束，來複製此光子碰撞實驗，則將無法產生新的大質量粒子。反而，會看到兩個光束結合，形成更亮的光束。
“If you go back and look at Maxwell’s equations for classical electromagnetism, you’ll see that two colliding waves sum up to a bigger wave,” says Simone Pagan Griso, a researcher at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). “We only see these two phenomena recently observed by ATLAS when we put together Maxwell’s equations with special relativity and quantum mechanics in the so-called theory of quantum electrodynamics.”
美國能源部所屬勞倫斯柏克萊國家實驗室(Berkeley Lab)研究員，Simone Pagan Griso宣稱：「倘若回顧並探究古典電磁學的麥克斯韋方程組，則會看到兩個碰撞波總合成一個更大的波。當他們將麥克斯韋方程組與狹義相對論，及在所謂量子電動力學理論中的量子力學併凑在一起時，他們僅看到，最近由ATLAS實驗觀測到的上述兩種現象。」
Inside CERN’s accelerator complex, protons are accelerated close to the speed of light. Their normally rounded forms squish along the direction of motion as special relativity supersedes the classical laws of motion for processes taking place at the LHC.
在歐洲核子研究組織的加速器設備內，質子被加速接近光速。當狹義相對論取代，在大型强子對撞機中，發生之過程的古典運動定律時，它們通常成圓形的形狀沿著運動方向擠壓。
The two incoming protons see each other as compressed pancakes accompanied by an equally squeezed electromagnetic field (protons are charged, and all charged particles have an electromagnetic field). The energy of the LHC combined with the length contraction boosts the strength of the protons’ electromagnetic fields by a factor of 7500.
兩個剛開始的質子彼此視同，由同樣擠壓之電磁場(質子是帶電的，因此所有帶電粒子皆具有電磁場)伴隨的壓縮煎餅。大型强子對撞機的能量，結合長度收縮(也被稱為洛倫茲收縮，是指觀察者在觀察與其相對速度非零的物體時，看到之長度變小的現象)，提升了質子的電磁場強度達7500倍。
When two protons graze each other, their squished electromagnetic fields intersect. These fields skip the classical “amplify” etiquette that applies at low energies and instead follow the rules outlined by quantum electrodynamics. Through these new laws, the two fields can merge and become the “E” in E=mc².
當兩個質子相互摩擦時，它們被擠壓的電磁場相交。這些電磁場跳過，適用於低能量的古典“放大”規則，而依循由量子電動力學概述的準則。透過這些新法則，這兩個電磁場會合併，而成為E =mc²中的“E”。
“If you read the equation E=mc² from right to left, you’ll see that a small amount of mass produces a huge amount of energy because of the c² constant, which is the speed of light squared,” says Alessandro Tricoli, a researcher at Brookhaven National Laboratory – the US headquarters for the ATLAS experiment, which receives funding from DOE’s Office of Science.
布魯克海文國家實驗室(接受來自美國能源部科學局資助之環狀大型強子對撞機設備實驗的美國總部)研究員，Alessandro Tricoli宣稱：「倘若從右至左讀出E =mc²該等式，則會看到，由於c²常數(光速的平方)，少量的質量產生大量的能量。
But if you look at the formula the other way around, you’ll see that you need to start with a huge amount of energy to produce even a tiny amount of mass.”
不過，倘若以另一種方式檢視此公式，則會看到，需要以大量的能量，來產生甚至很少量的質量。」
The LHC is one of the few places on Earth that can produce and collide energetic photons, and it’s the only place where scientists have seen two energetic photons merging and transforming into massive W bosons.
LHC是地球上，能產生及碰撞高能光子的少數地方之一，且這是科學家們已經發現兩個高能光子，合併及轉變成大質量W玻色子的唯一地方。
The generation of W bosons from high-energy photons exemplifies the discovery that won Sheldon Glashow, Abdus Salam and Steven Weinberg the 1979 Nobel Prize in physics: At high energies, electromagnetism and the weak force are one in the same.
從高能光子產生W玻色子，是Sheldon Glashow、Abdus Salam 及Steven Weinberg獲得1979年諾貝爾物理學獎之發現，在高能量下，電磁與弱力是同樣一體的例證。
Electricity and magnetism often feel like separate forces. One normally does not worry about getting shocked while handling a refrigerator magnet. And light bulbs, even while lit up with electricity, don’t stick to the refrigerator door. So why do electrical stations sport signs warning about their high magnetic fields?
電與磁往往感覺像是分開的力。人們通常並不擔心處理冰箱磁鐵時，會被電擊。而燈泡，即使用電點亮，也不會粘在冰箱門上。那麼，為何發電站引人注目地標示，有關其高磁場的警告標誌？
“A magnet is one manifestation of electromagnetism, and electricity is another,” Tricoli says. “But it’s all electromagnetic waves, and we see this unification in our everyday technologies, such as cell phones that communicate through electromagnetic waves.”
Tricoli宣稱：「磁是電磁的一種顯現，而電是另一種。不過，這全是電磁波。因此，在咱們諸如透過電磁波通信的手機等日常科技中，看到了此一致性。」
At extremely high energies, electromagnetism combines with yet another fundamental force: the weak force. The weak force governs nuclear reactions, including the fusion of hydrogen into helium that powers the sun and the decay of radioactive atoms.
在極高能量下，電磁與另一種基本力結合在一起：弱力。弱力左右包括，為太陽及放射性原子衰變，提供動力之將氫融合成氦的核反應。
Just as photons carry the electromagnetic force, the W and Z bosons carry the weak force. The reason photons can collide and produce W bosons in the LHC is that at the highest energies, those forces combine to make the electroweak force.
就如同光子傳導電磁力，W及Z玻色子也傳遞導弱力。在LHC中，光子會碰撞並產生W玻色子的原因是，在最高能量下，那些力結合形成電弱力。
“Both photons and W bosons are force carriers, and they both carry the electroweak force,” Griso says. “This phenomenon is really happening because nature is quantum mechanical.”
Griso宣稱：「光子及W玻色子兩者是力載體，因此它們皆傳導電弱力。這種現象確實正在發生，因為大自然是屬量子力學的。」
原文網址：https://newscenter.lbl.gov/2020/09/23/lhc-creates-matter-from-light/
翻譯：許東榮
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