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A view of the center of the ATLAS |
Technion researchers are playing important roles at the LHC project in CERN – the world’s most powerful particle accelerator. Recently, news reports say the greatest scientific experiment in history has had amazing results and that the Higgs Boson – alias the “God particle” – has been discovered.
During the sixties and seventies, a model was developed that explains phenomena observed in the world of particles that comprise the entire universe. The model, which is called the “Standard Model”, explains brilliantly and accurately all experimental results and observations. But this model has originally had a problem: it could not be used to explain particles that have a mass. It is simply that mathematically, the equations did not hold if the mass of these particles was added to them. In the mid-sixties, several physicists, among them Peter Higgs, suggested what is currently known as the “Higgs mechanism”, through which mass can be added to the Standard Model. But adding this mechanism meant that a new particle had to exist – the Higgs Boson. We have been searching for it ever since. Last night, the world was told of its discovery.
This is, without a doubt, a technological achievement, but the real achievement is not in the technological realm, but rather in the news that the model we have been following is likely the correct one. We have, in fact, completed our first puzzle. We can now safely proceed in search of the next puzzle, namely the “new physics” or “physics beyond the Standard Model”, where we investigate phenomena that are not described by the Standard Model. Each such discovery, if made, will completely change our perception of the universe around us.
The Technion group has made a major contribution to the discovery, in that the construction and examination of the muon detectors, which are a critical part of the experiment’s ability to measure the events, were done in Israel. The muon detection software was developed by Prof. Tarem, and Prof. Rozen is responsible for the tremendous grid computing system. Students guided by Prof. Tarem developed the detector control system, and several students and researchers are now working under her guidance on one of the Higgs decay channels, as presented in the press conference last night.
About three years ago, only a moment before the huge tunnel in which the accelerator was built was sealed, Avi Blizovsky visited the place and we now bring his impressions once again.
We visited “ATLAS” – one of the main detectors in the LHC project in CERN. In a modest office in building number 40 – one of the main buildings on the CERN campus – seats Prof. Shlomit Tarem, of the High Energy Group in the Technion’s Department of Physics. Prof. Tarem is participating in the project together with her colleague in the group, Prof. Yoram Rozen, and their graduate students. The office houses also post-doctoral fellow Sofia Vallecorsa (originally of Rome) and doctoral student Sagi Ben-Ami. Among the Israeli group members are also researchers from the Weizmann Institute and Tel Aviv University. With them works Arwa Bannoura, a student from Birzeit who lives in Bethlehem, and who is currently in CERN for the summer semester.
The Israeli group is headed by Giora Mikenberg of the Weizmann Institute, who has held in the past formal positions in CERN. According to Mikenberg, the credit for Israel joining the project is due, first and foremost, to the late Prof. Paul Singer of the Technion’s Department of Physics, who served as Chairman of the Israel Science Foundation.
During its construction, Israeli engineers collaborated with engineers of the Pakistan Atomic Energy Commission, and Israeli equipment allows fast and accurate optical communications between the facilities and the enormous server cluster. Many Israeli companies participated in building “ATLAS”, the huge facility that comprises 2,700 detectors on eight “wheels” 20 meters in diameter. Once the tunnel was sealed in August it could no longer be entered, which emphasizes the importance of the examinations conducted toward this move, to avoid technicians having to enter the tunnel in order to make repairs once the experiment begins.
The different elements of the CERN project were indeed examined prior to the start of the experiment, but the operation of the project as a whole could not be tested at the time. As was announced, the project was shut down for two months shortly after it began, because of a helium leak, but Prof. Tarem cautions against any concern. “This experiment will last for at least a decade, so two months are not too significant a period. Besides, malfunctions cannot be avoided in such a big, complicated experiment.”
Today, Profs. Tarem and Rozen and thousands of their colleagues worldwide can smile with pride and satisfaction. They were part of the discovery of the “God particle”.
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A graphic diagram of the particle accelerator in Geneva
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From right to left: Eli Hadash, Shikma Bressler, Silvia Behar, David Cohen, Yoram Gernitzky, Alon Hershenhorn and Yaniv Katan. In the second row: Sofia Vallecorsa, Dikla Oren, and Enrique Kachomovitz. Prof. Rozen (horizontal). |