Rutgers plays key role in mining data from world’s biggest particle accelerator
Rutgers physicist Matthew Strassler's research cited in New York Times' science section November 25.
Rutgers is a small but important part of the world’s largest physics experiment: a massive accelerator under the French-Swiss border near Geneva that will reveal some of nature’s most basic subatomic particles – the building blocks of all things.
Known as the Large Hadron Collider (LHC), the accelerator, which began operating in September, could unlock mysteries about the makeup of our universe, while posing new questions that will keep future generations of physicists very busy.
“The LHC will change fundamental physics, and Rutgers will be at the forefront of the search for results,” said Amitabh Lath, associate professor of physics and astronomy in the School of Arts and Sciences. That’s because Rutgers researchers, who make up a tiny fraction of the world’s 10,000 scientists, engineers, and technicians involved in the project, are contributing essential electronic equipment to LHC instruments and are poised to analyze the wealth of new data the LHC will produce.
This could include finding the elusive Higgs boson – a particle thought to give mass to all matter in nature – as well as discovering exotic particles or phenomena that physicists have yet to predict, Lath said.
Lath’s claim is more than a boast. It’s based on the department’s years of experience working on a similar but smaller particle accelerator at Fermi National Accelerator Laboratory (Fermilab) outside Chicago. More so, it is based on the department’s diverse mix of experimental and theoretical high-energy physicists, not typically found in other universities or institutions.
The accelerator will change
fundamental physics, and Rutgers
will be at the forefront of the
search for results.– Amitabh Lath
“We have a very close collaboration here, which is quite unusual,” said Professor Matthew Strassler, one of the theoretical physicists. “Rutgers is one of few universities or institutes where theorists and experimentalists sit down the hallway from each other. This allows for routine and spontaneous interaction, not just yearly meetings at professional conferences.”
Ten faculty and staff, six postdoctoral researchers, and seven graduate students are involved with the project, along with seven undergraduate researchers, two of whom are supported by Aresty Research Program grants. Historically, Rutgers’ high-energy physics team has had excellent undergraduates. “They’ve gone on to graduate schools at Stanford, Santa Barbara, Princeton, and Harvard – basically, the best,” Lath said. And because of the LHC’s scientific visibility and glamour, undergraduates are competing for coveted research positions.
Rutgers joined the LHC effort in 1997 during its planning and construction phase, working on one of two major proton collision detectors called the Compact Muon Solenoid (CMS). The team’s first job was to design and build custom electronic chips for what is essentially a 60-million pixel digital camera in the CMS detector. Taking 40 million pictures a second, it will capture traces of subatomic debris that scatter from protons colliding head-on, just shy of the speed of light. These pictures will show evidence of subatomic particles that have colorful names such as quarks, bosons, leptons, mesons, muons, and gluons.
The chips, designed by Rutgers Professor Stephen Schnetzer and physicist Robert Stone, along with electrical engineer Edward Bartz, will route the rapid-fire signals from the camera’s pixels to computers for storage and analysis. The chips are “radiation hard,” meaning the silicon circuits resist breakdown in the high radiation environment of the LHC.
The researchers also are working on instruments that use diamond sensors to take measurements close to the proton beam. In these instruments, thin slices of diamond replace silicon to detect particles streaking through them. Diamond-based detectors are impervious to radiation damage, and, while more expensive, they are in some ways easier to make than comparable silicon-based detectors.
One instrument already in the CMS uses Rutgers diamond technology – a radiation detector that will verify the quality of the proton beams circulating in the LHC.
Another instrument that will use diamond detectors is being designed to measure the intensity of the proton collisions. And yet another is on the drawing board to replace the current silicon-based camera. Both will be part of the proposed “Super LHC” upgrade in 2015 that will increase the intensity of proton collisions tenfold.
When officials fired up the LHC on September 10, Professor Yuri Gershtein was on-site in Geneva and among the first to detect evidence of the proton beam circulating around the 27-kilometer racetrack. A magnet failure the following week has postponed the first proton collisions until next May, but Rutgers physicists remain busy sharpening plans on how they will gather and analyze data. They would be glad to catch an early glimpse of the prized Higgs boson, unseen but predicted by a roadmap called the “Standard Model” of physics. But their main mission is to search for particles and interactions of which no one has yet conceived.
“We’re looking for something new that is outside the Standard Model, something we call new physics or exotic physics,” said Assistant Professor Eva Halkiadakis. She notes that Rutgers has a track record in such efforts: Professor Sunil Somalwar just finished a study that the physics community regards as the best search to date for unique pairings of particles known as supersymmetric particles.
The highly publicized controversy about whether the LHC would actually create black holes – star-like objects so dense that their massive gravitational pull doesn’t allow light to escape – actually had its roots at Rutgers. The first scientist to propose the possibility was Associate Professor Scott Thomas, in a paper he published six years ago in the journal Physical Review.