After nearly 15 years of planning and construction, the world’s most powerful particle accelerator — the Large Hadron Collider — successfully completed its first experiment last Wednesday.
Amidst a flurry of media attention, a beam of protons thinner than a human hair was steered around the 16.8-mile ring hundreds of feet below the Alps along the Franco-Swiss border. This initial success marks the beginning of a ground-breaking scientific endeavor to prove or disprove the Standard Model of creation on which particle physics currently operates.
“It’s a machine which we expect will make some very important discoveries,” said Prof. Gerald Dugan, physics. “There are very good ideas to believe that our Standard Model of physics, when extended into the LHC, will fail for some fundamental reasons. We expect to make observations that we can’t explain, and that will shed some light on how we can proceed.”
Within the next six to eight weeks, the European Organization for Nuclear Research (CERN) will begin colliding beams of protons in an attempt to produce both dark matter and the Higgs boson, which is the last unobserved particle postulated by the Standard Model.
Tarek Anous ’08, a Cornell alumnus now at Harvard pursuing a Ph.D. in applied physics, explained the importance of the Higgs boson.
“They’re looking for dark matter and the Higgs boson, the particle that is supposed to give mass to all particles. I guess you could call it the fundamental mass giver,” he said. “It’s important because particle physics hasn’t been able to prove its existence so far, and its part of the Standard Model. They really want to observe to see if it exists.”
“There is good reason to believe that we haven’t seen them because they are too heavy to be seen in current accelerators,” Dugan said. “This theory ties up the loose ends of the Standard Model.”
Whether the LHC proves or refutes the Standard Model, the physics community is excited to have the means to answer some long-awaited questions.
“I think that we are very excited about the possibility of answering some questions that have been troubling all of us for a long time. We are close to having a device that can help us answer these questions,” said Prof. David Rubin, physics.
“It will at least point us in the direction of where to go now, because particle physics is at a dead end. There are a lot of things that need to be measured that haven’t,” Anous said.
The breakthrough device and its subsequent experiments have placed Europe back at the head of scientific innovation. CERN General Director Robert Aymar stated in a press release that the LHC would “restore Europe to its rightful place at the forefront on science, and in particular, at the forefront of physics.”
“We lost the leadership in this field, and it is now in Europe. How we are going to gain leadership is not obvious,” Dugan said.
“It’s definitely the ball being passed to Europe. And there is no project in the pipeline that would bring it back into the U.S.,” said Prof. Peter Wittich, physics.
The U.S. had the opportunity to build an even more powerful supercollider, but the project was terminated in 1993 after the proposed budget rocketed from four billion dollars to 12 billion.
“It’s going to make it so that Europe has the most advanced technology, which the U.S. could have had if they hadn’t pulled the plug on the superconducting supercollider that they were building in Texas. It would have been even bigger than the LHC,” Anous said.
Rubin was hopeful that the U.S. could pursue an International Linear Collider (ILC) that would focus on electron and anti-electron collision if the results from the LHC necessitate further experimentation.
“We certainly could win back our advantage if America was willing to make certain investments, but I’m not sure that they will,” Rubin said. “There is a lot of interest in the U.S. to build the next generation of supercolliders. I think that in a couple of years, we will have some results from the LHC, and, based on those, we can make an educated guess about whether or not the ILC would be a good investment.”
Meanwhile, as the only University home to a particle accelerator — the Cornell Electron Storage Ring (CESR) — Cornell is heavily involved in the LHC project.
“Cornell is involved at the physics department and the Laboratory for Elementary-Particle Physics. Perhaps a dozen or so professors are collaborators and they are helping to get some very sophisticated instrumentation working,” Rubin said. “They are working on the detectors and they will be involved in analyzing the data that comes out of these experiments.”
Wittich, who makes several visits a year to the LHC, and spent six weeks at the site this summer, expanded on Cornell’s role in the experiment.
“I’ve been working on this since 2005. There were precursory experiments at Wilson Lab, which were a smaller scale of the LHC that have been going on for 30 years. We’re doing the science here on campus.” Wittich said. “We have been heavily involved in custom software development — writing the underlying software that all the scientistists will use, called the software framework. We’ve also been heavily involved in the commissioning of the experiment, which is taking this from a set of individual components to a cohesive whole.”
According to Wittich, there are 25 to 30 Cornellians involved in the development of the software, and several faculty members involved in the main experiments. On seeing the behemoth structure, Wittich stated that he was struck by the ease of international collaboration.
“It’s fantastic. You have this lab entirely dedicated to this science, and the energy that comes from all working together towards the same thing is incredible,” Wittich said. “We have scientists from all over the world in our group. The international boundaries are not that important. I was in the control room in July, and this guy was having technical conversations in French, German, Italian and English.”
Despite the initial success, the LHC experiments are proceeding extremely slowly due to safety concerns and a need for the scientists to become familiar with the complex equipment.
“It’s a very complicated device — a lot of pieces need to work just right, and it’s a very time consuming process,” Rubin said. “They need to be extremely careful because when the beam is circulating, it has a lot of energy, and if the beam goes off course it could do a lot of damage by melting something. They would have to fix the damage and have to re-cool the whole system, and that’s a couple of months process.”
The entire device is kept at 1.9 degrees Kelvin – two degrees from absolute zero, making it the world’s largest cryogenic facility. Other than the possibility of misteered beams, one fear highlighted by the media was the possible creation of black holes by the collisions that could swell and swallow the Earth. However, all four professors and Anous dissuaded this theory.
“Black holes radiate and evaporate. These micro-black holes would evaporate so fast they wouldn’t do anything,” Anous said.
“That will be really cool if that happens, but its not going to,” Rubin joked.
However, the negative attention garnered by these apocalyptic predictions has managed to fluster some in the physics community. Some concerned citizens have even gone so far as to send death threats to scientists at MIT.
“I had mixed feelings about the media’s portrayal. On one hand it’s great people hear about the science, but you have people who are genuinely worried, and they think this apocalypse is going to happen,” Wittich said. “A lot of the complaints we get are that we are megalomaniacal scientists bent on the destruction of the planet, so it’s a little distressing.”
But the LHC’s debut has heartened physicists who don’t often see their work at the forefront of the international news arena.
“It’s exciting to have a big physics project get a lot of news, it doesn’t happen often. The really exciting time will be when data begins to get analyzed, but that’s still a ways off,” Rubin said.