翻译一篇英文文章《The race to break the standard model》
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发布时间：2022-04-30 07:57
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时间：2022-06-19 09:47
因此，物理学家一直在试图超越标准模型以往任何时候都因为它是把20世纪70年代。实际上，他们将打破该模型与实验数据，违背其近乎完美的方程。然后，从它的碎片，他们必须建立一个新的，更好的理论。大型强子对撞机（复合） ，一个巨大的粒子加速器在欧洲核子研究中心，欧洲粒子物理实验室附近，瑞士日内瓦，是最新试图打破标准模型-之一，许多人认为所有，但成功的保证。在庞大的能源产生将迫使粒子领域的标准模型无法贯彻。在比赛中超越现状“的复合体是迄今最喜欢的”说，弗兰克威尔茨克，一个理论家在麻省理工学院在剑桥谁赢得了2004年诺贝尔物理学奖，他的工作所依据的标准模式。
但是，复合不是唯一的。几十年来，物理学家曾试图超越标准模型的各种方法，有时加速器，有时用精密测量惊险罕见的事件，有时观察外层空间。在时间的复合体得到充分加速-它的第一批结果预计不会，至少到明年夏天（见'的阻挡对撞机' ） -一些实验组认为他们有一个战斗的机会抓住第一个奖。他们的任务将难以：标准模型是一项艰巨的一块工作，抵制一切方便和明显的攻击。打击它，实验将需要前所未有的灵敏度，众多的数据，超过一点点运气。这里破败的英雄谁觉得几年最多的任务。
Tevatron
虽然得到了复合质子加速，世界上其他重量级粒子加速器赛车打破标准模型首次。自2001年以来， Tevatron ，位于费米实验室在巴达维亚，伊利诺伊州，一直在加速质子和反质子在能源约1万亿电子伏特。
这是只有七分之一的最终能源的复合体，但总能量是不是一切在寻找新的物理学。碰撞会产生新的粒子以外的标准模型是极其罕见的，这意味着不再是一个加速器运行和更多的数据积累，更好的机会找到的东西。因此，一段时间，至少Tevatron将继续有一个数据，领先的复合体。即使是夏天到2009年， Tevatron将有几倍的数据总量超过其新的竞争对手。
已经这些数据显示出一些诱人的，如果暂时的，暗示的东西超出了标准模型。一个有偏差的测量粒子被称为奇怪的乙（布）介子。该旅馆是一个奇异夸克和反夸克底部，它是最重的所有介子。根据规则被称为电荷宇称对称性，标准模型预言的旅馆衰变以同样的方式作为其反粒子（提出的反奇怪底部和夸克） 。但是，测量两个暗示的差异及其衰变。据德米特里杰尼索夫，发言人的D -零实验在Tevatron ，这一差异可能是一个重要的线索在寻求发现。这可能预示着存在新的，充满异国情调的粒子，或以前未知的原则。在任何情况下，杰尼索夫说， “这是一个激动人心的测量。 ”
异常的旅馆并不是唯一的怪人出现在加速器，增加了罗伯特Roser ，一个发言人Tevatron的其他主要实验，碰撞探测器实验室，或民防部队。不寻常的功能衰减的对顶部和反顶夸克了他的好奇。同样，他承认，这远不能肯定。但一些这些信号可能是重要的， Roser说。 “当您新增的数据之一， [这些不正常现象]可以成为现实。 ”
也许这并不奇怪，更怀疑的看法来自约翰埃利斯，一个在欧洲核子研究中心的理论家。是的， Tevatron可以提供一些诱人的暗示说，埃利斯，但它是不可能作出明确的发现之前，复合体是强大的。在世界上的粒子物理，他指出，没有构成发现，直到它是衡量五个σ （ 5个标准偏差的平均值） ，相当于99.99994267 ％的准确度。更多的数据比Tevatron积累了迄今将需要达到严格的标准，该探测器是不可能使这些大幅上涨之前，它是超越了其新的竞争对手。 “我认为它会非常，非常难的Tevatron ， ”埃利斯说。 “我只是不想看到他们之前获得的复合体始于去迸发。 ”
宇宙
虽然高能量物理学家聚集在他们的机器的控制室，另一组物理学家正在寻找的天堂。因此，他们希望找到的东西打破了标准模型-如果宇宙的合作。
最主要的，他们的航天器将寻找迹象表明暗物质的幽灵物质，可以弥补多达85 ％的事项宇宙中。天文学家知道，暗物质的存在不仅是因为它的引力对星系及其对宇宙的形状;它似乎传递正确的通过什么样的普通物质中发现恒星，行星和人民。据推测，暗物质是一种烟雾颗粒很少，如果有的话，反应的普通品种。但是，没有人是相当确定这些粒子可能-除非他们不占的标准模式。
一位候选人是来自'超对称理论，预测，每一个粒子的标准模型，另一个躺在较重的合作伙伴以外的模式。最轻的超对称伙伴被称为neutralino ，并预计将刚才的权利性质是暗物质。
Neutralinos本身将不会被望远镜，轨道或以其他方式。但是，定期，两个neutralinos可能发生碰撞和消灭-创造一个淋浴普通的粒子轨道探测器可能回升。尤德夫（载荷为探索物质的反物质和轻核天体物理）实验已经看到一个有趣的线索。该卫星传播的工具收报盈余的反电子，可能已经产生的黑暗物质annihilations （见自然454 ， 808 ; 2008年） 。 “这是一个美丽的结果，说： ”格拉谢Gelmini ，物理学家在加州大学，洛杉矶，谁看到东区的数据。不过，她补充说，复杂的测量需要谨慎。
第二，最近推出的卫星还可以现场不幸去世的neutralino 。在费米伽玛射线太空望远镜是美元690万美元的空间文书，旨在扫描整个天空的超高能量光子。这是可能的，这种γ射线可以建立由neutralino碰撞，在这种情况下，他们将显示为无处不在烟雾中的轨道探测器的天空地图。 “这将是一个惊人，惊人签字，说： ”史蒂芬酒店，该望远镜项目科学家，美国航天局戈达德太空飞行中心绿地，马里兰州。
这些签字，如果他们发现并确认的时间，肯定有机会战胜复合体在寻求突破的标准模型，特纳说，迈克尔，一个宇宙学家在芝加哥大学的在伊利诺伊州。但是，酒店指出，虽然在技术上天体物理学会首先作出这样的发现，他们不能做更多的事情了。反电子， γ射线和其他类似的签名可以提供物理学家只有一个粗略的大规模一系列新粒子，并更不用说超对称如何可能的工作。由于这些原因“仍然会有大量的必不可少的问号” ，说酒店-问题，就必须解决的复合体。
不可阻挡的对撞机
至于自然到新闻界，大型强子对撞机（复合）在欧洲核子研究中心，欧洲粒子物理实验室日内瓦附近，即将循环第一质子。但有很多事情要做的机器前制作发布的科学发现。在未来的几个月，甚至运营商微调对撞机本身，其他物理学家将设法让实验间隔周围环启动和运行。
开关探测器上的大小建设是一项不小的任务。每种乐器是成千上万的小探测器，它必须同步轨道的粒子所产生的碰撞。该探测器目前正在进入调整利用宇宙射线来自外层空间说，彼得珍妮的发言人阿特拉斯（环形复合体装置）的实验。但是，观看真正的粒子碰撞将是一个完全不同的问题。碰撞质子束将产生数以亿计的独特的'事件'每一秒钟，每一事件，包括数百或数千碎片粒子飞行外向从碰撞点。由于探测器的目的是跟踪大多数或所有这些粒子单独，结果将是更多的数据远远高于experimentalists可以处理。幸运的是，绝大多数的碰撞会产生，这只是一起普通。因此，实验者已经配备的电子探测器' triggers'that单独的有趣碰撞的休息。例如，一个简单的标记将触发碰撞proce'muons ' -粒子，可创造的衰变更大规模的粒子。每个触发将被设计为保存证据某种有趣的活动，每个国家都必须认真加以调整，根据珍妮。
经过数据的筛选，他们必须analysed.To为此，数据从实验将被发送到成千上万的物理学家通过大规模的网格计算，可以穿梭PB的数据，大学实验室，遍布世界各地。初步试验进展顺利，吉姆Virdee说的发言人契约μ介子螺线管（不育系）在欧洲核子研究中心实验，另一项重大试验，并在阿特拉斯队和不育系现在钻探与计算机生成的实际数据。
假如一切顺利，珍妮和Virdee都说，结果最早可能在2009年夏天。到那时，加速器应已运行了几个月的充分7万亿电子伏的力量，有时间已经理清任何技术问题。
请问复合找到一些新的物理学中，首先运行？有可能。该机器将会碰撞粒子大约7倍的能量，目前世界上领先的加速器，在Tevatron ，位于费米实验室在巴达维亚，伊利诺伊州。这是一个大跳跃，它原则上，才有可能看到新的粒子几乎立即表示， Virdee 。 “你不需要很多数据，以探测超出实验室做了， ”他说。
费米实验室的物理学家怀疑这是可以理解的这种评价。花了两个整年工作的物理学家在Tevatron可以充分把握其特点的实验，说
罗伯特Roser ，一个发言人在碰撞检测实验室。甚至与更高的能量，将需要大量的碰撞中找到一些新的，德米特里杰尼索夫说，在一名发言人费米实验室的D -零的实验。 “一个质子对撞与质子中心的检测是不够的， ”他说。 G.B
黑暗
其他物理学家选择黑暗的光。从他们的lairs内废弃矿山和交通隧道，他们观看了一些高度敏感的探测器，可以找到直接签字的暗物质，包括超对称neutralinos （见自然448 ， 240 ; 2007年） 。
大约有50个不同的计划，这种探测器，但它们都遵循同样的基本概念。采取一些东西你觉得可以应付的暗物质，将其放置地下深处，以保护它从宇宙射线和其他破坏性的影响，并等待什么发生。 “这就像看基层成长，说： ”威尔茨克。
虽然他们也许不是最令人兴奋的方式击败了复合体，这些探测器正在显着进展。一个实验中，低温暗物质搜寻二，或CDMS二，目前正在积累数据的在苏丹矿井深处明尼苏达州。其经营目标是三冠王其目前的敏感性今年年底。另一项实验要求XENON100 ，位于隧道意大利大萨索山，随时有机会第一次出结果之前，复合的探测器能完成处理他们的调查结果。 “外地会这么快，有这么多的竞争，这是不容易生存的时刻，说： ”选手阿波西勒，主要调查员XENON100在纽约哥伦比亚大学。 “这是一个惊人的时间。 ”
再加上这些前景，一组声称，它已经发现了暗物质在其探测器。今年早些时候，按需分配/天秤座（暗物质大批量碘化钠珍稀过程）实验，也在大萨索国家实验室宣布，它已看到了信号在其最新一代的探测器（见自然452 ， 918 ; 2008年） 。但他们发现有其他团体难倒说，阿波西勒，其实验坐落在一个地窖旁边的按需分配/天秤座。没有其他人尚未能够确认信号，而事实上，调查结果从其他球队看起来是矛盾的，她说。 “我们肯定不会一致。 ”
尽管这些探测器似乎是在改善跨越式发展，他们有一个致命的弱点：他们只是工作，如果迄今看不见的黑暗物质粒子相互作用，至少偶尔会，并定期此事。没有保证，这种情况下，埃利斯说。至于他的关心，使这些实验的“球在黑暗中。 ”
不过，埃利斯承认，有机会，这些深奥的搜索可能会设法看到面前的复合体可以。 “我认为，黑暗物质家伙是jokers的包， ”他说。
中微子
今后几个月将是一个咖啡因燃料模糊的大部分这些科学家争先恐后地击败了复合体。但中微子物理学家可以很容易：他们已经新的突破，他们没有在十年前。
中微子是中性的成员'轻子'家庭的粒子，该集团，其中包括电子。原始版本的标准模型预言，中微子应该完全massless ，但另有experimentalists怀疑。多年来，他们看到少中微子从太阳比理论预测。一个可能的解释为赤字，太阳能中微子可以从一个转换到另一个类型。但是，开关将有可能只有当中微子有质量。 1998年，日本实验飞弹所谓的超级神冈看到了中微子开关的行动，这一结果是第一次-迄今为止唯一的-公司发现，违抗标准模型。
不幸的是，埃利斯说，中微子的质量可容纳的标准模型，使只是几个简单的修改方程。 “这是有可能增加一些在相对容易， ”他说。因此，虽然中微子物理学可以说索赔的奖金，他们发现没有帮助理论家在他们寻找新的物理模型。
但是，中微子可能不只是尚未完成。实验在美国，欧洲和日本正在发射的中微子束在其探测器的尝试，以了解更多关于如何切换中微子从一种到另一个。确切的细节交换可能有助于缩小可能的领域中新的理论模型，兰德尔说，丽莎，一个理论家在哈佛大学，马萨诸塞州坎布里奇。
和两个新的探测器可能会进一步仍在。欧洲的合作是现在运行的天文望远镜和中微子深渊环境研究（火星）探测器在地中海海岸的土伦，法国，和一队的美国人正在安装IceCube的冰层南极洲。同时使用字符串探测器看到高能量宇宙中微子来源惊人的水或冰。安塔里斯完成今年夏季早些时候，而IceCube大约有一半的70串的探测器安装。但是，已经IceCube是美国的5倍以上更敏感超级神冈，根据弗朗西斯Halzen ， IceCube的主要调查员在威斯康星大学麦迪逊分校。 “这不是我们想象的可以找到的东西， ”他说。
究竟这东西可能是为辩论。一种可能性是中微子产生的黑暗物质粒子被困在Sun的核心。但是， Halzen说，什么都看到了中微子实验几乎肯定会需要采取后续行动的复合体。 “我认为这些实验是相辅相成的， ”他说。 “但如果你给我一个选择，我宁愿看到它第一次。 ”
成功？
因此，任何能够对这些项目的最佳标准模型？威尔茨克是持怀疑态度。 “我不是边缘的我的座位， ”他说。看记录，看来， “标准模型总是赢” 。他认为，只有复合体随时有真正的机会，打破现有的模式。
而且也没有保证，即使是巨型对撞机将找到新的东西。 “超对称性可以随时显示中期至2009年，从来没有， ”埃利斯说。如果是从来没有的日期，他说，物理学家将面临“最大的恐怖情景可以想象。 ” “什么，我们这样做呢？ ”他问。
但特纳采取了不同的看法。归根结底，这些实验和复合体战斗的战斗在一起。他相信，通过他们的数据相结合的复合的，标准模型可以击败，新物理学会被发现。 “我们正在接近一个重大*， ”他说。
杰夫Brumfiel是一个资深记者自然总部设在伦敦。
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热心网友
时间：2022-06-19 09:48
热心网友
时间：2022-06-19 09:48
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时间：2022-06-19 09:49
因此，物理学家一直在试图超越标准模型以往任何时候都因为它是把20世纪70年代。实际上，他们将打破该模型与实验数据，违背其近乎完美的方程。然后，从它的碎片，他们必须建立一个新的，更好的理论。大型强子对撞机（复合） ，一个巨大的粒子加速器在欧洲核子研究中心，欧洲粒子物理实验室附近，瑞士日内瓦，是最新试图打破标准模型-之一，许多人认为所有，但成功的保证。在庞大的能源产生将迫使粒子领域的标准模型无法贯彻。在比赛中超越现状“的复合体是迄今最喜欢的”说，弗兰克威尔茨克，一个理论家在麻省理工学院在剑桥谁赢得了2004年诺贝尔物理学奖，他的工作所依据的标准模式。
但是，复合不是唯一的。几十年来，物理学家曾试图超越标准模型的各种方法，有时加速器，有时用精密测量惊险罕见的事件，有时观察外层空间。在时间的复合体得到充分加速-它的第一批结果预计不会，至少到明年夏天（见'的阻挡对撞机' ） -一些实验组认为他们有一个战斗的机会抓住第一个奖。他们的任务将难以：标准模型是一项艰巨的一块工作，抵制一切方便和明显的攻击。打击它，实验将需要前所未有的灵敏度，众多的数据，超过一点点运气。这里破败的英雄谁觉得几年最多的任务。
Tevatron
虽然得到了复合质子加速，世界上其他重量级粒子加速器赛车打破标准模型首次。自2001年以来， Tevatron ，位于费米实验室在巴达维亚，伊利诺伊州，一直在加速质子和反质子在能源约1万亿电子伏特。
这是只有七分之一的最终能源的复合体，但总能量是不是一切在寻找新的物理学。碰撞会产生新的粒子以外的标准模型是极其罕见的，这意味着不再是一个加速器运行和更多的数据积累，更好的机会找到的东西。因此，一段时间，至少Tevatron将继续有一个数据，领先的复合体。即使是夏天到2009年， Tevatron将有几倍的数据总量超过其新的竞争对手。
已经这些数据显示出一些诱人的，如果暂时的，暗示的东西超出了标准模型。一个有偏差的测量粒子被称为奇怪的乙（布）介子。该旅馆是一个奇异夸克和反夸克底部，它是最重的所有介子。根据规则被称为电荷宇称对称性，标准模型预言的旅馆衰变以同样的方式作为其反粒子（提出的反奇怪底部和夸克） 。但是，测量两个暗示的差异及其衰变。据德米特里杰尼索夫，发言人的D -零实验在Tevatron ，这一差异可能是一个重要的线索在寻求发现。这可能预示着存在新的，充满异国情调的粒子，或的
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时间：2022-06-19 09:49
The Large Hadron Collider is the latest attempt to move fundamental physics past the frustratingly successful 'standard model'. But it is not the only way to do it. Geoff Brumfiel surveys the contenders attempting to capture the prize before the collider gets up to speed.
Geoff Brumfiel
ILLUSTRATIONS BY J. RIORDANIt is powerful; it is galling; it is doomed. The incredibly successful mathematical machine that physicists call the 'standard model' is a set of equations that describes every known form of matter, from indivial atoms to the farthest galaxies. It describes three of the four fundamental forces in nature: the strong, weak and electromagnetic interactions. It predicts the outcome of one experiment after another with unprecedented accuracy. And yet, as powerful as it is, the standard model is far from perfect. Its mathematical structure is arbitrary. It is littered with numerical constants that seem equally ad hoc. And perhaps most disturbingly, it has resisted every attempt to incorporate the last fundamental force: gravity.
So physicists have been trying to get beyond the standard model ever since it was put together in the 1970s. In effect, they will have to shatter the model with experimental data that contradict its near-perfect equations. And then, from its fragments, they must build a newer, better theory. The Large Hadron Collider (LHC), a giant particle accelerator at CERN, Europe's particle-physics laboratory near Geneva, Switzerland, is the latest attempt to break the standard model — and one that many see as all but assured of success. The prodigious energy it generates will force particles into realms where the standard model cannot follow. In the race to move beyond the status quo, "the LHC is by far the favourite", says Frank Wilczek, a theorist at the Massachusetts Institute of Technology in Cambridge who won the 2004 Nobel Prize in Physics for his work underpinning the standard model.
But the LHC is not the only game in town. For decades physicists have tried to get beyond the standard model in all sorts of ways, sometimes with accelerators, sometimes with precision measurements of breathtakingly rare events, sometimes with observation of outer space. And in the time it takes for the LHC to get fully up to speed — its first results aren't expected until at least next summer (see 'The unstoppable collider') — some of those experimental groups think that they have a fighting chance of seizing the prize first. Their task will be hard: the standard model is a formidable piece of work that has resisted all the easy and obvious attacks. To crack it, experiments will need unprecedented sensitivity, a multitude of data, and more than a little luck. Here's a rundown of the heroic few who feel up to the task.
Tevatron
While the LHC gets its protons up to speed, the world's other heavyweight particle-accelerator is racing to break the standard model first. Since 2001, the Tevatron, located at Fermilab in Batavia, Illinois, has been accelerating protons and antiprotons at an energy of around 1 tera electron volt.
That's only a seventh of the eventual top energy of the LHC, but total energy isn't everything in the hunt for new physics. Collisions that would generate new particles outside the standard model are extremely rare, which means that the longer an accelerator runs and the more data it accumulates, the better its chances of finding something. So for a while, at least, the Tevatron will continue to have a data lead over the LHC. Even by the summer of 2009, the Tevatron will have several times more total data than its new competitor.
And already those data are showing some tantalizing, if tentative, hints of something beyond the standard model. One deviation comes in measurements of a particle known as the strange B (Bs) meson. The Bs is made of a strange quark and an anti-bottom quark, and it is among the heaviest of all mesons. Under a rule known as charge-parity symmetry, the standard model predicts the Bs will decay in the same way as its antiparticle (made of an anti-strange and a bottom quark). But measurements of the two are hinting at a difference in their decays. According to Dmitri Denisov, a spokesperson for the D-Zero experiment at the Tevatron, that difference could be an important clue in the quest for discoveries. It might signal the existence of new, exotic particles, or of previously unknown principles. In any case, says Denisov, "it's an exciting measurement".
The Bs anomaly is not the only oddity showing up at the accelerator, adds Robert Roser, a spokesperson for the Tevatron's other major experiment, the Collision Detector at Fermilab, or CDF. An unusual feature in the decays of pairs of top and anti-top quarks has him intrigued. Again, he admits, it's far from certain. But some of these signals may turn out to be important, Roser says. "As you add data, one of [these anomalies] may become real."
Perhaps not surprisingly, a more sceptical view comes from John Ellis, a theorist at CERN. Yes, the Tevatron could provide some tantalizing hints, says Ellis, but it is unlikely to make a definitive find before the LHC comes on strong. In the world of particle physics, he points out, nothing constitutes a discovery until it is measured to five σ (five standard deviations from the mean), the equivalent of 99.99994267% accuracy. Much more data than the Tevatron has accumulated so far will be needed to reach that exacting standard, and the detector is unlikely to make those big gains before it is overtaken by its new rival. "I think its going to be very, very tough for the Tevatron," Ellis says. "I just don't see them getting it before the LHC starts going gangbusters."
Cosmos
While the high-energy physicists gather in their machine's control rooms, another group of physicists is looking to the heavens. There they hope to find something that shatters the standard model — if the Universe cooperates.
The main thing that their spacecraft will look for are indications of dark matter, the ghostly substance that could make up as much as 85% of the matter in the Universe. Astronomers know that dark matter exists only because of its gravitational pull on galaxies and its influence on the Universe's shape; it seems to pass right through the kind of ordinary matter found in stars, planets and people. Presumably, dark matter is a haze of particles that rarely, if ever, react with the ordinary variety. But nobody is quite sure what those particles might be — except that they are not accounted for in the standard model.
One candidate comes from the 'supersymmetry' theory, which predicts that every particle in the standard model has another, heavier partner lying outside the model. The lightest of these supersymmetric partners is called the neutralino, and is predicted to have just the right properties to be dark matter.
Neutralinos themselves wouldn't be seen by telescopes, orbiting or otherwise. But periodically, two neutralinos could collide and annihilate — creating a shower of more mundane particles that orbiting detectors might pick up. The PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) experiment has already seen an intriguing clue. The satellite-borne instrument has unofficially reported a surplus of anti-electrons that may have been generated by dark-matter annihilations (see Nature 454, 808; 2008). "It's a beautiful result," says Graciela Gelmini, a physicist at the University of California, Los Angeles, who has seen PAMELA's data. Still, she adds, the complexities of the measurement require caution.
A second, recently launched satellite may also be able to spot the untimely demise of the neutralino. The Fermi Gamma-ray Space Telescope is a US$690-million space instrument designed to scan the entire sky for ultra-high-energy photons. It is possible that such γ-rays could be created by neutralino collisions, in which case they would show up as a ubiquitous haze in the orbiting detector's sky-map. "That would be a stunning, stunning signature," says Steven Ritz, the telescope's project scientist at NASA's Goddard Space Flight Centre in Greenbelt, Maryland.
Such signatures, if they're spotted and confirmed in time, definitely have a chance to beat the LHC in the quest to break the standard model, says Michael Turner, a cosmologist at the University of Chicago in Illinois. But Ritz points out that although astrophysics could technically be the first to make such a discovery, they can't do much more than that. Anti-electrons, γ-rays and other such signatures could provide physicists with only a rough mass range for the new particles, and would say nothing about how supersymmetry might work. For those reasons "there would still be a large number of essential question marks", says Ritz — questions that would have to be resolved at the LHC.
The dark
Other physicists have chosen darkness over light. From their lairs inside disused mines and traffic tunnels, they are watching a number of highly sensitive detectors that could find direct signatures of dark matter, including supersymmetric neutralinos (see Nature 448, 240; 2007).
There are around half-a-dozen different schemes for such detectors, but they all follow the same basic concept. Take some stuff you think could respond to dark matter, place it deep underground to protect it from cosmic rays and other disruptive influences, and wait for something to happen. "It's like watching grass grow," says Wilczek.
Although they are perhaps not the most exciting way to beat the LHC, these detectors are making impressive progress. One experiment, the Cryogenic Dark Matter Search II, or CDMS II, is currently accumulating data in the Soudan Mine deep beneath Minnesota. Its operators aim to treble its current sensitivity by the end of the year. Another experiment called XENON100, located in a tunnel under Italy's Gran Sasso Mountain, stands a chance to have its first results out before the LHC's detectors can finish processing their findings. "The field is going so fast and there's so much competition, that it's not easy to survive at the moment," says Elena Aprile, the principal investigator for XENON100 at Columbia University in New York. "It's an amazing time."
And on top of these prospects, one group claims that it has already seen dark matter in its detector. Earlier this year, the DAMA/LIBRA (Dark Matter Large Sodium Iodide Bulk for Rare Processes) experiment, also at the Gran Sasso National Laboratory, announced that it had seen a signal in its latest generation of detector (see Nature 452, 918; 2008). But their finding has the other groups stumped, says Aprile, whose experiment sits in a vault next to that of DAMA/LIBRA. No one else has yet been able to confirm the signal, and in fact, the findings from other teams seem contradictory, she says. "We are definitely not consistent."
Although these detectors seem to be improving in leaps and bounds, they have an Achilles heel: they only work if the so-far unseen dark-matter particles interact, at least occasionally, with regular matter. There's no guarantee that that is the case, says Ellis. And as far as he's concerned, that makes these experiments "shots in the dark".
Still, Ellis concedes that there is a chance that these esoteric searches might manage to see something before the LHC can. "I think the dark-matter guys are the jokers in the pack," he says.
Neutrino
The next few months will be a caffeine-fuelled blur for most of those scientists racing to beat the LHC. But neutrino physicists can take it easy: they've already broken new ground, and they did it a decade ago.
Neutrinos are the neutral members of the 'lepton' family of particles, the group that includes the electron. The original version of the standard model predicted that neutrinos should be completely massless, but experimentalists suspected otherwise. For years they saw fewer neutrinos from the Sun than theorists predicted. One possible explanation for the deficit was that solar neutrinos could be switching from one type to another. But that switching would be possible only if neutrinos had mass. In 1998, a Japanese experiment in Hida called Super-Kamiokande saw the neutrino switch in action, and that result is the first — and to date the only — firm finding that defies the standard model.
Unfortunately, says Ellis, the neutrino's mass can be accommodated within the standard model by making just a few simple modifications to the equations. "It's possible to add something in relatively easily," he says. And consequently, although neutrino physicists can arguably claim the prize, their discovery hasn't helped theorists in their search for new models of physics.
But neutrinos may not be finished just yet. Experiments in the United States, Europe and Japan are now firing beams of neutrinos at their detectors to try to learn more about how the neutrinos switch from one kind to another. The precise details of this switching may help narrow the field of possible new theoretical models, says Lisa Randall, a theorist at Harvard University in Cambridge, Massachusetts.
And two new detectors could go further still. A European collaboration is now running the Astronomy with a Neutrino Telescope and Abyss Environmental Research (ANTARES) detector under the Mediterranean Sea off the coast of Toulon, France, and a team of Americans is installing IceCube beneath the ice of Antarctica. Both use strings of detectors to see high-energy neutrinos from cosmic sources striking water or ice. ANTARES was completed earlier this summer, whereas IceCube has about half of its 70 strings of detectors installed. But already IceCube is five times more sensitive than Super-Kamiokande, according to Francis Halzen, IceCube's principal investigator at the University of Wisconsin, Madison. "It's not inconceivable we'll find something," he says.
Just what that something might be is up for debate. One possibility would be neutrinos proced by dark-matter particles trapped in the Sun's core. But again, Halzen says, anything seen by the neutrino experiments would almost certainly require follow-up by the LHC. "I think these experiments are complementary," he says. "But if you give me a choice, I'd rather see it first."
Success?
So can any of these projects best the standard model? Wilczek is sceptical. "I'm not on the edge of my seat," he says. Looking the track record, it seems that, "the standard model always wins". He believes that only the LHC stands a real chance of breaking the existing paradigm.
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And there's no guarantee that even the giant collider will find something new. "Super symmetry could show up anytime between mid-2009 and never," says Ellis. If never is the date, he says, physicists will face "the maximum conceivable horror scenario". "What will we do next?" he asks.
But Turner takes a different view. Ultimately, these experiments and the LHC are fighting the battle together. He is confident that by combining their data with the LHC's, the standard model can be bested, and that new physics will be discovered. "We're on the verge of a major revolution," he says.
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时间：2022-06-19 09:50
在大型强子对撞机是最新的尝试移动基本物理过去的令人沮丧的成功的标准模型。但它不是唯一的方式做到这一点。杰夫Brumfiel调查的竞争者试图捕捉奖之前对撞机获得加速。
杰夫Brumfiel
插图由J. RIORDANIt是强大的，它是烦恼，这是注定。难以置信的成功的机器，数学物理学家称之为标准模型是一组方程，描述每一个已知形式的问题，从单个原子的最远的星系。它描述的三个四个基本部队的性质：强者，弱和电磁相互作用。它预测的结果之一另一个实验后以前所未有的精度。然而，作为强大的，因为它是标准模型是远远不够完善。其数学结构是任意的。这是充满了数值常数，似乎同样特设的。也许是最令人担忧的是，它一直抵制一切试图将过去的基本力：重力。
因此，物理学家一直在试图超越标准模型以往任何时候都因为它是把20世纪70年代。实际上，他们将打破该模型与实验数据，违背其近乎完美的方程。然后，从它的碎片，他们必须建立一个新的，更好的理论。大型强子对撞机（复合） ，一个巨大的粒子加速器在欧洲核子研究中心，欧洲粒子物理实验室附近，瑞士日内瓦，是最新试图打破标准模型-之一，许多人认为所有，但成功的保证。在庞大的能源产生将迫使粒子领域的标准模型无法贯彻。在比赛中超越现状“的复合体是迄今最喜欢的”说，弗兰克威尔茨克，一个理论家在麻省理工学院在剑桥谁赢得了2004年诺贝尔物理学奖，他的工作所依据的标准模式。
但是，复合不是唯一的。几十年来，物理学家曾试图超越标准模型的各种方法，有时加速器，有时用精密测量惊险罕见的事件，有时观察外层空间。在时间的复合体得到充分加速-它的第一批结果预计不会，至少到明年夏天（见'的阻挡对撞机' ） -一些实验组认为他们有一个战斗的机会抓住第一个奖。他们的任务将难以：标准模型是一项艰巨的一块工作，抵制一切方便和明显的攻击。打击它，实验将需要前所未有的灵敏度，众多的数据，超过一点点运气。这里有一个破败的英雄谁觉得几年最多的任务。
Tevatron
虽然得到了复合质子加速，世界上其他重量级粒子加速器赛车打破标准模型首次。自2001年以来， Tevatron ，位于费米实验室在巴达维亚，伊利诺伊州，一直在加速质子和反质子在能源约1万亿电子伏特。
这是只有七分之一的最终能源的复合体，但总能量是不是一切在寻找新的物理学。碰撞会产生新的粒子以外的标准模型是极其罕见的，这意味着不再是一个加速器运行和更多的数据积累，更好的机会找到的东西。因此，一段时间，至少Tevatron将继续有一个数据，领先的复合体。即使是夏天到2009年， Tevatron将有几倍的数据总量超过其新的竞争对手。
已经这些数据显示出一些诱人的，如果暂时的，暗示的东西超出了标准模型。一个有偏差的测量粒子被称为奇怪的乙（布）介子。该旅馆是一个奇异夸克和反夸克底部，它是最重的所有介子。根据规则被称为电荷宇称对称性，标准模型预言的旅馆十
