On the morning of April 4, a dozen students and postdoctoral fellows gathered in the offices of Elena Aprile, a Professor of physics at Columbia University, to get their first look at the data from an experiment across the world. In a deep tunnel under a Gran Sasso (Italy), Dr. Aprile and an international team of scientists had connected a vessel containing liquid Xenon 134 books to save the pit-pat of invisible particles, the so-called dark matter that astronomers say is a quarter of the universe.
Photographers were on hand to record the action - after all, you never - know although theoretical calculations suggest that, with only 100 days of observation, the experience of Xenon is probably still shy of the necessary time to see the dark matter. "We will not discover dark matter today", said Dr. Aprile. "We will be doing this again and again.".
A dark matter teased and tantalized physicists since the 1970s when it has been shown that some invisible documents must provide the gravitational glue to hold the galaxies together. Knowing that it is might provide a roadmap of new particles and forces, a new view of what happened in the Big Bang, and more Nobel prize you can count. Failed to find it would mean that Einstein did not have the laws of gravity quite right.
The best guess is that this dark matter is composed of clouds of exotic subatomic particles flying over from the Big Bang and generically called wimps, for weakly interacting massive particles that can pass through the Earth as the smoke through a door screen.
Some particle physicists hope to produce in the large Hadron Collider of hadrons out of Geneva or read their signature in cosmic rays from space. Just to experience the Alpha magnetic spectrometer, which is scheduled to be launched into space and installed on the International Space Station later this month. Other physicists, including Dr. Aprile team, tried to catch the putative detectors all particles far underground to guard against contamination by cosmic rays.
For the last year that in the eyes of the physical world were on the experience of Dr. Aprile in the Gran Sasso, part of the Italy National Lab National Institute of nuclear physics, which is widely recognized as the largest and most sensitive detector there. She hopes to save the characteristic signal - a bump and a flash - to the rare collision of a wimp with a Xenon nucleus. The experience began last year and ran for 100 days.
At the push of a button data, invisible up to now to guard against unconscious bias, would start circulating in an analysis pipeline and appear as red dots on a big computer screen.
On a table in the corner is a stack of folded yellow notepapers, on which collaboration members had written their bets on events how - putative matter dark detections - would be recorded. They ranged from 20, by an optimistic graduate student, and 2 to a skeptical astrophysicist. Increased tension and Vertigo in the room: 10: 30 Date deadline came and went, due to computer problems.
Finally, the promised chart appears on the screen, showing the first 91 batches of data. A red dot appears, the first signal of event. He was quickly joined by another and then another, each accompanied by a sharp breath in room supply.
"Oh, God," Dr. Aprile said as the number increased to four. "" "". I cannot sit anymore. "She got up from his chair.
There is more to OH Papa as the count has risen to six, more would be expected of the radioactivity of the background to the detector and finally stopped.
Everybody applauded, and Dr. Aprile went around the room offering of hugs and kissing the cheeks. But the results, she admitted, were ambiguous.
"Six points mean nothing until they have been analyzed", she said. "I am optimistic about the future." We have much more to do. ?
Indeed, collaborators soon laid three of these points, concluding that they were caused by noise in electronics.
"We knew that less than 10 minutes," said Rafael Lang of Columbia. "It was quite clear."
That left with three events, compared to the two recitals of substance, not a large enough disparity to request proof of a WIMP. Wednesday night group of Dr. Aprile posted a paper on the www.arXiv.com Web site physics and Physical Review Letters, saying that they did had not yet detected any wimps.
But the group refused to be disappointed. The results, members, said, had set new and more stringent limits on the nature of the putative dark matter particles, eliminate some theoretical models, as well as to show that the detector occurred at the height. Dr. Aprile called "a spectacular result."
Neal Weiner, a theorist of the particle at the University of New York, agreed, noting that it was only the first results of an experiment that will continue for years and get more sensitive. If there is any dark matter in their data set, they will not wait years to discover, said, "we just have to wait until later this year."
Dr. Lang said: "it is the sense of the community that something new and big is just around the corner." We did there not immediately but perhaps we are not far, and it is very exciting. ?
Dr. Aprile said they would definitely do this again.
In an e-mail to the Italy, she wrote, "I know nothing more exciting than a signal, but when we seek the unknown, we probe more we arrive at the truth.".
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