The University of California, Santa Cruz, will host an international gathering of particle physicists this week to discuss the development of a next-generation international particle accelerator facility. The Santa Cruz Linear Collider Retreat, June 26 to 29, will begin with a public presentation on the science of particle physics on Wednesday evening.
There will be two public lectures on Wednesday, June 26, starting at 7 p.m. in Theater Arts Building M, Room 110. Helen Quinn, a theoretical physicist at the Stanford Linear Accelerator Center (SLAC), will speak on "The Science of Particle Physics." Rick Van Kooten, a physicist at Indiana University, will speak on "The Next Mega Machine: The Linear Collider." The talks are free and open to the general public.
The UCSC meeting is one of a series of meetings of the American Linear Collider Physics Group, which is developing plans for a next-generation linear collider facility, currently referred to simply as the Linear Collider. Physicists use powerful accelerators and colliders to study the fundamental particles of matter and the forces between them. The new Linear Collider is being designed to extend the study of particle physics beyond the capacity of current machines.
The Santa Cruz Institute for Particle Physics (SCIPP) at UCSC is already involved in research and development of detector technology for the Linear Collider, said Bruce Schumm, associate professor of physics. Schumm, who is organizing the Santa Cruz meeting, leads one of the project's working groups.
The current prevailing theory of particle physics, called the Standard Model, is based on decades of research at accelerator facilities. It has held up well despite repeated challenges, but precision measurements at currently available energies can only be understood by postulating new phenomena at energies that will be accessible at the next generation of particle colliders. Research at these higher energies will provide new insights about the nature of matter and the forces that shape the universe, and may possibly alter our notions of space and time, Schumm said.
To develop the Linear Collider, U.S. particle physics labs are working cooperatively with the Deutsches Elektronen-Synchrotron (DESY) in Hamburg, Germany, and the High Energy Accelerator Research Organization (KEK) in Tsukuba, Japan. Two possible U.S. sites for the Linear Collider have been identified--FermiLab, near Chicago, and a site near Davis, California. DESY is a possible European site, and Japanese scientists are expected to describe potential sites in Japan at the Santa Cruz meeting.
The Linear Collider project would take many years to complete, and the facility would not begin operation until sometime after 2010, Schumm said. Before then, physicists will begin using the Large Hadron Collider (LHC), currently under construction at the European Organization for Nuclear Research (CERN) in Geneva, Switzerland. The LHC is a proton-proton collider, producing collisions between protons at higher energies than currently possible.
The Linear Collider will be an electron-positron collider. Unlike protons, which are composed of smaller particles called quarks and gluons, electrons and positrons are indivisible particles. This means that the results from the Linear Collider will be easier to interpret than those from the LHC. The two facilities will give particle physicists complementary information, Schumm said.
The Higgs boson, a theoretical particle that may explain how fundamental particles acquire mass, will be a primary focus of attention at both LHC and the Linear Collider.
"The LHC will almost certainly detect the Higgs boson if it exists, but the Linear Collider will enable us to make precise measurements of the properties of the Higgs particle to determine whether it behaves as predicted and to see if it does in fact solve the problems that it is predicted to solve," Schumm said.
About 150 physicists are expected to attend the Santa Cruz meeting, including the directors of several national and international physics laboratories, as well as representatives from the U.S. Department of Energy and the National Science Foundation.
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Editor's note: Reporters may contact Schumm at (831) 459-3034 or schumm@scipp.ucsc.edu.
