First Collisions Recorded at the LHC with 7.0 TeV Beams


Today, Tuesday March 30, 2010 at 6:58 AM EST the LHC collided beams at 3.5 TeV per beam for the very first time. The long awaited event proceeded smoothly and without incident and culminated with the delivery of 600,000 events to the CMS experiment. The day also marks the beginning of data taking for the physics experiments at the LHC, something that has been in the making since 1992 when the LHC was firts proposed. Since then experimenters have been anxiously awaiting this new frontier at the highest energy and luminosity in pursuit of physics beyond the standard model. The unprecedented energy and collision rates will yeild important insights in to the origin of mass, the make up of mater and energy and nature of space-time. It is truly and exciting day for the HEP group at FIU, the HEP community beyond and the physics in general. To follow along on the latest check out the CERN public web site at Also visit us at our new CMS Center now under construction and soon to be installed in CP 257.

The plot shows neutral pions reconstructed from the first 600,000 events collected with CMS at 7 TeV on March 20, 2010. This plot was amongst the first created shortly after data was delivered. It showcases CMS' prompt-online data analysis capabilities. Neutral pions are common by-products of collisions at HEP experiments. While they decay too quickly, 10 millionth-billionth of a second, to be observe directly they can be easily spotted by reconstructing their decays into two photons. Note: all correction have yet to be applied to this distribution, thus the mass, indicated by the central value of the peak, is off by 19 MeV from the known mass.