Physicists today welcomed the beginning of a new era in particle physics with the first successful traverse of the Large Hadron Collider (LHC) by protons. At the University of Arizona, Elliot Cheu, Associate Dean of the College of Science, Professor of Physics, and a member of the LHC-ATLAS team, spoke to the public about the event and upcoming particle physics research using the LHC.
University of Arizona President Robert Shelton and Cheu kicked off “From the Big Bang to Dark Matter: Turning on the Large Hadron Collider” with confirmation that the largest particle accelerator ever built had been successfully activated around 12:30 AM Arizona Time this morning. Over the next hour, researcher at the LHC, located on the border of France and Switzerland near Geneva, successfully sent a proton all the way around the 27 kilometer ring. UA physicists had a good reason for spending a sleepless night awaiting updates on this test run: several components of ATLAS, one of the six LHC experiments, were designed and built here.
ATLAS will detect the spray of particles that result from the collisions between two protons. Cheu compared the multi-story ATLAS to an onion; various layers of instrumentation can detect different classes of particles made of quarks (known as hadrons.) These include electrons, protons, neutrons, muons, and perhaps new particles never before detected. For example, a theorized particles called the Higgs Boson is especially important to the Standard Model of particle physics. Some scientists believe the Higgs Boson gives matter its mass. Should ATLAS and other experiments in the LHC detect this particle, then theoretical updates to the Standard Model will be confirmed. If not, then the Standard Model, an otherwise very successful model of particles in our universe, may be in trouble.
With today’s race around the ring, how far are we away from results? Cheu said the first collisions between protons injected into the ring in opposite directions could come later in September or in October. Terabytes of data will be collected and analyzed for evidence of new particles created in these colossal collisions. According to Cheu the first scientific results could come as soon as Spring 2009.
LHC and its instruments will also look for particles that might make up dark matter, explore the nature of photons and cosmic rays, and tell us something about the conditions believed to exist in the universe less than a second after the Big Bang.
All these terabytes of data requires analysis. UA researchers have become software programmers, said Cheu, to help turn data about collisions and their resulting data into useful graphs and other abstractions. Meanwhile, advances in networking, GRID computing and software technology were required to meet the needs of the experiment. This technological progress could benefit the existing internet in upcoming years.
Addressing concerns about the danger of turning on the LHC, Cheu highlighted some of the physics that would make Earth-eating microscopic black holes and stranglets unlikely, if not completely impossible. Natural particle accelerators and the existence of neutron stars suggest that these dangers do not exist. Even if these dangers did exist, based on various calculations they would take far longer than the remaining age of the Sun to present any threat to the Earth.
The discovery of the electron in 1897 heralded the birth of the particle physics discipline, but it was not immediately clear how it would impact everyday life, if at all. In fact, over the past century, the discovery of this particle led to electricity, television, computers, cellphones, and much more. Cheu suggested that new particles detected by the LHC could also radically change our lives over the coming decades.
The LHC was built by the European Organization for Nuclear Research (CERN). It was first conceived of in the early 1980s and formally approved in December 1994. Construction began at the end of that decade and was completed this year. Over the coming months and years, scientists will explore reality at scales tinier and more elusive than atoms.
- Large Hadron Collider (LHC)
- “CERN – The Large Hadron Collider“
- The ATLAS Experiment
- University of Arizona