KU research team helped find the Higgs boson

Philip Baringer, a Kansas University professor of physics and astronomy. Photo courtesy of Kansas University.

KU professor of physics and astronomy Alice Bean. Photo courtesy of Kansas University.

Circulating among researchers in Kansas University’s Malott Hall is an ever-so-slightly altered reproduction of Tuesday’s announcement of the Nobel Prize in physics. From a few feet back it reads, “The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2013 to… the ATLAS and CMS experiments at CERN’s Large Hadron Collider.”

Don’t mind the acronyms for now, because they didn’t, and can’t, win the Nobel. Look closer and you’ll see, in teeny tiny print after the “to,” the names of theoretical physicists Peter Higgs and Francois Englert, who developed the idea for the Higgs boson, and who were the actual winners of the prize.

Behind the gentle joke is a huge international collaboration of experimental scientists who worked to confirm the ideas of Higgs and Englert. That includes a KU team of physicists who helped build sensors for the Large Hadron Collider, the miles-long particle accelerator used to create a Higgs boson by smashing it free of colliding protons.

The team recently won a $1.78 million grant from the National Science Foundation to continue its work with the Hadron. Philip Baringer, a KU professor of physics and astronomy, heads the team with researchers Alice Bean, David Besson and Graham Wilson, all of whom are physics and astronomy faculty as well. KU’s involvement with the Hadron and the European Organization for Nuclear Research, or CERN, goes back to the late 1990s.

Looking for needles in haystacks

Right now the team is working on testing prototypes of upgraded sensors that will go into what Baringer describes as the “ginormous detector” at the Hadron. The multi-layered cylinder of sensors enveloping the accelerator, which lies nearly 100 meters underground near Geneva, Switzerland, looks like something Darth Vader might walk out of.

The sensors at the collider help measure the paths and emitted energy of debris particles flung out by collisions of protons inside the accelerator. The sensors themselves work similarly to a digital camera, but work at incredible speeds, taking the equivalent of 40 million pictures per second.

Those sensors helped identify a particle announced as a Higgs boson in July 2012. The announcement set the physics world ablaze and captured the imagination of much the public.

Higgs bosons are particles predicted in the Standard Model of particle physics, which posits a field that all particles pass through, and which is ultimately responsible for giving particles their mass. Baringer said that the Standard Model was mathematically solid and showed much experimental confirmation, but if the Higgs had gone unfound, it would have blown a major hole in the Standard Model.

Back to the drawing board

Baringer and Bean will both tell you they would almost rather have not found the Higgs. In the days leading up to last July’s announcements, when data analysis was being culled by researchers to determine what, exactly, they had found inside the accelerator, Bean and a colleague would say to each other, “God, we hope it’s not the Higgs.”

“We were hoping not to find it because that would be even more surprising,” she said.

For an experimental physicist, it’s just no fun to confirm an idea posited by the theorists. “I always like telling them they have to go back to the drawing board,” Bean said.

Even with the elusive Higgs identified, the Large Hadron collider could still hold surprises. Plenty questions remain about the world of the very small. As Bean explains, much of the universe’s matter remains a mystery in the form of “dark matter,” accounted for by physicists, but unexplained.

Once the accelerator, which shut down in February, comes back online it will have double the energy with which to smash protons into each other. There’s no telling what might come out.