GENEVA (AP) – To cheers and standing ovations from scientists, the world's biggest atom smasher claimed the discovery of a new subatomic particle Wednesday, calling it "consistent" with the long-sought Higgs boson — popularly known as the "God particle" — that helps explain what gives all matter in the universe size and shape.

"We have now found the missing cornerstone of particle physics," Rolf Heuer, director of the European Center for Nuclear Research (CERN), told scientists.

He said the newly discovered subatomic particle is a boson, but he stopped just shy of claiming outright that it is the Higgs boson itself — an extremely fine distinction.

"As a layman, I think we did it," he told the elated crowd. "We have a discovery. We have observed a new particle that is consistent with a Higgs boson."

The Higgs boson, which until now has been a theoretical particle, is seen as the key to understanding why matter has mass, which combines with gravity to give an object weight. The idea is much like gravity and Isaac Newton's discovery of it: Gravity was there all the time before Newton explained it. But now scientists have seen something very much like the Higgs boson and can put that knowledge to further use.

CERN's atom smasher, the $10 billion Large Hadron Collider on the Swiss-French border, has been creating high-energy collisions of protons to investigate dark matter, antimatter and the creation of the universe, which many theorize occurred in a massive explosion known as the Big Bang.

Two independent teams at CERN said Wednesday they have both "observed" a new subatomic particle — a boson. Heuer called it "most probably a Higgs boson, but we have to find out what kind of Higgs boson it is. "

Asked whether the find is a discovery, Heuer answered, "As a layman, I think we have it. But as a scientist, I have to say, "'What do we have?'"

"It is consistent with a Higgs boson as is needed for the standard model," Heuer said. "We can only call it a Higgs boson — not the Higgs boson."

The leaders of the two CERN teams — Joe Incandela, head of CMS with 2,100 scientists, and Fabiola Gianotti, head of ATLAS with 3,000 scientists — each presented in complicated scientific terms what was essentially extremely strong evidence of a new particle.

Incandela said it was too soon to say definitively whether it is the "standard model" Higgs that Scottish physicist Peter Higgs and others predicted in the 1960s — part of a standard model theory of physics involving an energy field where particles interact with a key particle, the Higgs boson.

The phrase "God particle" was coined by Nobel Prize-winning physicist Leon Lederman but is used by laymen, not physicists, as an easier way of explaining how the subatomic universe works and got started.

【新闻快讯】

 欧洲核子中心4日举行新闻发布会，宣布已经观测到“类似‘上帝粒子’特性的一颗新粒子”。该中心总主任罗夫·赫尔博士称，人类在理解自然世界上跨越了一个崭新阶段。

 欧洲核子中心人员在台上伴着泣声，眼含泪花，激动地宣布，ATLAS和CMS两个通用大型实验结果显示，在125吉电子伏特（GEV） 的质量附近发现了一颗新粒子，其特性类似于粒子物理学界一直努力于寻找的“希格斯玻色子”，也被称为“上帝粒子”。

这一重大新闻的宣布赢得现场热烈的掌声。对“上帝粒子”作出预言的英国物理学家彼得·希格斯也参加了现场的新闻发布活动。参与实验值班的北京大学钱思进教授无比激动地对记者表示，这是50年来全球数千名科学家的艰辛努力所等待的结果。

新闻发布会上，CMS实验的新闻发言人饶·安岗德拉称，新发现的粒子应该是人类从未观测到的最重的一个玻色子，科学家们在研究和验证中极为谨慎。ATLAS实验的新闻发言人法彪拉·吉阿诺迪表示，这一骄人业绩令人兴奋。

钱思进教授表示，CMS实验的科研人员在2012年6月前记录数据上寻找标准模型中的希格斯玻色子终于取得了初步结果，分析显示新粒子的部分特性与“标准模型”中“上帝粒子”的预期一致，但这还仍需不断确认；大型强子对撞机目前在以引人注目的进度提供新数据。希望到2012年底数据样本总量翻3倍多，这些数据将使CMS能进一步阐明这种新粒子的本性；无论如何，今日新闻发布内容至少向世界表明，人类又发现了一颗新粒子，这也是粒子物理学界的又一重大发现。

据介绍，欧洲核子中心对过去两年积累的大量数据进行了细致分析，今年的部分数据仍在处理之中以待7月底发布；目前该中心还在等待后续的实验数据，估计年内会有更加全面的观测分析结果。

今年3月，欧洲核子中心决定提高欧洲大型强子对撞机的对撞能量，使得质子束流运行能量达到4万亿电子伏特，旨在对“上帝粒子”的存在空间尽快获得更清晰的和决定性的表述。