Sometimes, experiments lead the way in suggesting new particles. A decade ago, particle physics was abuzz when more than 10 experiments worldwidereported hints of a "pentaquark" - an agglomeration of four quarks and one antiquark that weighed half as much again as a proton.

有时实验会给出新粒子。十年前，世界范围内超过10个的实验揭示了"五夸克态"——凝聚了四个夸克和一个反夸克的束缚态，比质子多出一半的质量，这引发了粒子物理学家极大的兴趣。

Protons and other composite particles known in the standard model are either made from three quarks bound together, or are a ménage à deux of a quark and an antimatter antiquark. Yet there is no fundamental reason to believe weightier particles with combinations of four, five, six or even seven quarks and antiquarks don't exist, says particle theorist Frank Close of the University of Oxford. There are, however, very good reasons to believe we would be hard-pressed to spot them. A pentaquark, for example, would be expected to decay within less than 10-23 seconds - "about the time it takes for 0light to cross a particle", says Close.

标准模型中的质子和其他复合粒子要么是三个夸克结合在一起的，要么是一个夸克和一个反夸克结合在一起的。但是没有根本上的理由说重粒子态如四、五、六、七夸克和反夸克的组合不存在，牛津大学的粒子理论家Frank Close说。然而，有很好的理由相信我们会很难发现它们。例如一个五夸克态，预计将在小于10^-23秒内衰减——"所用的时间相当于光飞过一个粒子的尺寸"，Close说。

Our glimpse of pentaquarks certainly proved suitably fleeting. The presumed discoveries melted away in 2005 when a dedicated search for the particlesturned up nothing.

当时我们看到的五夸克态，最终被证明没有站得住脚。如果确实有这样的发现，2005年的一个专门设计的寻找实验应该能看到，但是结果并没有看到。

Yet even as pentaquarks have faded, there has been an uptick in sightings of "tetraquarks". These composite particles of two quarks and two antiquarks might be produced when an electron and its antiparticle, the positron, annihilate. The problem here, says Close, is one of interpretation: are we actuallyseeing true closely bound particles, or something more like "molecules" of two conventional quark-antiquark pairings loosely, and fleetingly, linked together?

然而即使五夸克态已经消失，现在又出现了四夸克态。这种两个夸克和两个反夸克的复合粒子可能会在电子和它的反粒子正电子湮灭时产生。问题就在于解释，Close说，我们实际看到的是真正的复合粒子，还是如同"分子"的两个传统的夸克反夸克对的松散的，飞离着的连在一起的对？

Such tales of particles found and lost gain resonance as we sieve through the LHC's outpourings. Is that really the Higgs boson, or a sign of supersymmetry - or will it too dissolve into thin air?

这样的发现而后又否定发现的情况将很可能在大型强子对撞机的运行中不断被反复。是真正的希格斯玻色子，或者超对称的信号，还是它最终将消失在空气中呢？

• fundamental [,fʌndə´mentl]   a.基本的 n.原理   (初中英语单词)
• glimpse [glimps]   n.&v.瞥见   (初中英语单词)
• actually [´æktʃuəli]   ad.事实上；实际上   (初中英语单词)
• dissolve [di´zɔlv]   v.(使)溶解；解除   (初中英语单词)
• decade [´dekeid]   n.十年(间)   (高中英语单词)
• particle [´pɑ:tikl]   n.微粒；极小量   (高中英语单词)
• oxford [´ɔksfəd]   n.牛津   (高中英语单词)
• interpretation [in,tə:pri´teiʃən]   n.解释；翻译；表演   (高中英语单词)
• seeing [si:iŋ]   see的现在分词 n.视觉   (高中英语单词)
• annihilate [ə´naiəleit]   vt.歼灭；消灭   (英语四级单词)
• conventional [kən´venʃənəl]   a.常规的；协定的   (英语四级单词)
• loosely [´lu:sli]   ad.松散地   (英语四级单词)
• fleeting [´fli:tiŋ]   a.飞逝的，疾驰的   (英语六级单词)