Rice Physicist to Direct $40M LHC Program

Rice University announced that physicist B. Paul Padley has been chosen to lead the scientific operations for one of the particle detector systems at the European Organization for Nuclear Research's Large Hadron Collider (LHC). Scheduled to begin operations next year, LHC will be the most powerful particle accelerator in the world.

Padley, associate professor of physics and astronomy, has been chosen to lead the scientific operations of the $40 million CMS Endcap Muon System, one of the major particle detector subsystems of the 13,000-ton Compact Muon Solenoid (CMS). Muons are short-lived particles that act much like electrons but are far more massive.

CMS is housed in a 27-km ring of subterranean tunnels in Cessy, France, just across the border from Geneva, and is run by the European Organization for Nuclear Research (CERN, an acronym derived from its former name, the Conseil Européen pour la Recherche Nucléaire). The CERN project team includes 2300 people from 159 scientific institutions.

Like most particle physics detectors, the heart of CMS is a powerful electromagnet. As subatomic particles fly away from the collisions inside the accelerator, they follow a curved track and pass through the detector's magnetic field. Based on the tracks the particles follow, scientists can distinguish the various particles based on their charge-to-mass ratios.

Simulation of a Higgs decay to four isolated muons in the CMS detector at the Large Hadron Collider at CERN. The lines denote particles produced from the collision of a pair of ultrahigh energy protons. Energy deposits of the particles in the detector are shown in blue. (Image: CERN)

A goal of CMS is to detect the rapid stream of muons that will be created in the LHC, which will smash together beams of protons traveling near light speed in order to recreate high-energy conditions that existed during the universe's infancy. Detection of muons is crucial at the LHC because they will play a key role in unveiling the physics of the Higgs field and of supersymmetry, two of the collider's primary goals, Padley said.

"Precise and reliable detection of muons is a notoriously difficult task at hadron colliders, but we must solve this problem at LHC if we are to adequately reconstruct the decay products of the Higgs particle," Padley said. "Most exciting of all, we may be able to shed light on the mysterious dark matter that pervades the universe."

The CMS Endcap Muon System consists of some 6000 square meters of muon detectors and approximately 400,000 electronic readout channels. Scientists have to design systems that can sift through the massive data stream flowing from the detectors in order to reconstruct the chain of events that occurs during each particle collision. For example, the path of each muon must be calculated to within one millimeter's accuracy in space and to within four nanoseconds accuracy in time.

"Some of the best minds in physics are working to ensure that the Endcap Muon System provides the best possible physics, and I count it as a rare honor to be able to take part," Padley said.

For more information, visit: www.rice.edu