UNL involvement in Large Hadron Collider startup

The first particle collisions at the Large Hadron Collider at the European Organization for Nuclear Research (CERN) near Geneva, Switzerland, took place Nov. 23 and the high-energy physics team at the University of Nebraska-Lincoln is already at work analyzing data.

The LHC, a particle accelerator nearly 17 miles in circumference that spans the border between Switzerland and France, is designed to study the building blocks of all matter. Two beams of subatomic particles called "hadrons" -- either protons or lead ions -- travel in opposite directions inside the circular accelerator, gaining energy with every lap. Physicists will use the LHC to recreate the conditions just after the Big Bang, by colliding the two beams head-on at very high energy.

Teams of physicists from around the world will analyze the particles created in the collisions using special detectors in a number of experiments dedicated to the LHC. UNL researchers are involved in one of the two largest experiments, the Compact Muon Solenoid (CMS), designed to investigate a wide range of physics, including the search for the Higgs boson, extra dimensions and particles that could make up dark matter.

In September 2008, only a few days after protons first circulated through the collider (but before collisions occurred), an electrical bus between two of the machine's superconducting magnets vaporized, causing a shutdown and a delay of more than a year in starting collisions. This time, things went much better.

"The LHC startup has been going shockingly well, with the first collisions happening (Monday), so soon after the first circulating beams on Friday," said Ken Bloom, associate professor of physics and astronomy and a member of UNL's high-energy physics team, along with professors Dan Claes, Aaron Dominguez, Ilya Kravchenko and Greg Snow, plus graduate and undergraduate students and postdoctoral researchers.

Two UNL postdoctoral researchers, Helena Malbouisson and Jamila Butt, were in the control room of the CMS experiment during the first collisions. Bloom said the team almost immediately started transferring data to the Holland Computing Center, mostly to the Red supercomputer in the Schorr Center on the UNL City Campus. He said Firefly, the Holland Computing Center's supercomputer at the Peter Kiewit Institute in Omaha has become the largest contributor in the world to the production of CMS simulations.

More information on the CMS experiment can be found at http://cms.cern.ch. More information about the LHC is available at http://public.web.cern.ch/public/en/LHC/LHC-en.html.