Successful first year of LHC operations
The first year of operating the Large Hadron Collider (LHC) at CERN near Geneva, Switzerland is coming to a successful end. Since March 2010 the LHC has provided collisions of protons with protons at a world record energy of 7 Trillion Electron Volts (TeV) inside the four large particle detectors.
An important target for 2010 was to reach a luminosity - a measure of the collision rate – of 10^32 per square centimeter per second. This was achieved on 13 October, three weeks before the end of the proton-proton collisions. CERN director general Rolf Heuer commented "The significance of this milestone can’t be underestimated, since it is a necessary step on the way to the larger goal of delivering an integrated luminosity of one inverse femtobarn to the experiments by the end of 2011. That’s the amount of data we need to ensure that if nature has put new physics in our path at the LHC’s current collision energy, we’ll have a good chance of seeing it." The main goal for 2011 is for the experiments to collect enough data - an amount known by the physicists as one inverse femtobarn, which is about 40 times more than the data taken this year - to make significant advances across a broad frontier of physics. The ATLAS experiment (along with the CMS, LHCb and ALICE experiments) has already entered new territory with its first measurements at the collision energy of 7 TeV. The results so far have included the validation of aspects of the Standard Model of particles and forces at these new high energies; the first observations of the top quark in proton-proton collisions; and limits set on the production of certain new particles, for example "excited" quarks. The high-energy physics group at Iowa State is part of the international ATLAS collaboration. The group consists of professors Chen, Cochran, Prell and Rosenberg, senior scientist Krumnack, postdocs, and graduate students. They are busy studying data that has been collected this year by the ATLAS experiment. Their research focuses on measurements of the production of J/ψ, D* and Z particles, top quark properties, search for the Higgs boson and new physics phenomena. ISU graduate student Andrew Nelson and ISU postdoctoral associate Arantxa Ruiz Martinez have already presented first results from the ATLAS experiment at international conferences this summer.