Ready for another round

The Large Hadron Collider is turning back on and Rice physicists have leadership roles 

Rice University physicist Paul Padley has been named manager of detector operations for the United States’ contribution to the Compact Muon Solenoid, a component of the world’s largest science experiment, the Large Hadron Collider.

The powerful accelerator, activated in 2008, fires protons at each other at near-light speed to break them down into more elemental particles and help scientists discover hidden truths about the universe.

Karl Ecklund, left, and Paul Padley. Photo by Jeff Fitlow

The newly upgraded collider will soon begin to look for sequels to the blockbuster 2012 discovery of the Higgs boson, the subatomic particle long suspected of giving mass to other fundamental particles.

Padley, a Rice professor of physics and astronomy, will manage the detector operations program funded by the Department of Energy and the National Science Foundation at $7 million annually. Scientists and students from many American universities — including five Rice professors and many postdoctoral researchers, graduate and undergraduate students — are part of the international project, the European Organization for Nuclear Research (aka CERN), based in Switzerland. (The circular collider itself straddles the border of Switzerland and France.)

“Rice is an important player in this international effort, with a big effort and people in leadership roles,” Padley said. Another Rice faculty member, Karl Ecklund, is the deputy manager of the Compact Muon Solenoid’s tracking system, a $100 million component of the experiment.

It’s an exciting time to take on a bigger role, Padley said. The nearly 17-mile-long collider is being prepared to start a new multiyear run with data collection beginning this summer. The energy of the accelerator will be almost double that of the previous run, and the experiments have been upgraded to operate at these previously unseen energies. These upgrades include electronic components designed and built at Rice.

“We are working hard to make sure we’re well-prepared for the startup of the collider,” Padley said.

One early task will be to reproduce the Higgs results. Last month, Compact Muon Solenoid collaborators presented refined data from the earlier run and showed their discovery is indistinguishable from the Higgs particle predicted by the Standard Model of particle physics, which explains how the building blocks of all matter interact. (Padley noted PBS’ recent Nova broadcast, “Big Bang Machine,” which featured Rice alumnus Don Lincoln ’90, offered “the best explanation I’ve seen on any TV program of the Higgs mechanism.”)

“Historically, whenever we’ve advanced the collision energy, new things show up in the data,” he said. “Last time it was the Higgs boson, and we know we’ll make lots more Higgs. We’re hoping for something new this time.

“Once you’ve discovered something new, it becomes a tool you can use for more new discoveries, just like the Higgs is now a tool. We can look for things that decay to the Higgs, or for it to decay to other things.”

Unlike the search for the Higgs, there is no “unique prediction” to dictate what scientists should look for next, he said. “We have a lot of different ideas to test, while also watching out for the new and unexpected. It could be we make breakthroughs by studying what we know with greater precision and see that it doesn’t quite mesh up with the model. Or we could make something completely new, which would be the dream scenario.”

Padley said physicists are hot on the trail of dark matter and dark energy, which can’t be seen directly but make up most of the universe. “We want to make some and try to figure out what it is. There are all kinds of theories about what it might be.”

In addition to Ecklund and Padley, Rice faculty members J. Roberts, Wei Li and Frank Geurts all work on the experiment, along with three postdoctoral researchers, seven graduate students and several undergraduate researchers.

Padley said these are busy times on the experiment. In addition to finishing up the analyses of data from the last run and preparing for the startup of the collider, upgrades are in the works for scheduled shutdowns in 2018 and 2025.

“We’ve embarked upon the improvements and upgrades that will be done for the next shutdown, because it takes that much time to get ready and build things,” he said. “And we’re planning and doing the initial design studies for upgrades in the 2020s. Through all this, Rice plans to be at the forefront of this tremendous project.”