by Lidiya SMIRNOVA, Dr. Sc. (Phys. & Math.), Skobeltsyn Research Institute of Nuclear Physics, Lomonosov Moscow State University
In late November 2009, the start of the Large Hadron Collider (LHC) was successfully accomplished at the European Center for Nuclear Research (CERN, Switzerland). Proton bunches within a pulse of 450 GeV/s were put into its ring, transported in two directions of circulation without additional acceleration and put together in collision areas. The detectors of interaction recorded the first collisions of particles at an energy of 900 GeV. In December 6-12 they were accelerated to the impulse value of 1.18 TeV/s. Since March 30, 2010, LHC is uninterruptedly working at an energy of proton collision of 7 TeV.
The LHC acceleration ring has four intersection points of oncoming proton beams, in which ATLAS, CMS, ALICE and LHCb* interaction detectors are constructed. The first two are of general purpose, and their basic task is search for Higgs boson and other new particles. ALICE is designed to find quark-gluon plasma. Its formation is expected at collisions of relativistic heavy nuclei, first of all of gold (Au), which will be also accelerated in the collider. LHCb is designed for stud-
* See: L. Smirnova, "The 21st Century Megaproject". Science in Russia, No. 5, 2009.-Ed.
ies of symmetry violation at B-meson decomposition and indirect observation of Higgs boson and other new particles in properties of such decompositions.
It should be noted that all these detectors were ready for operation by September 10, 2008, the date of the launch of the collider, but the heat removal system had failed. It took more than a year to eliminate the failure. Nonetheless, the detectors did not stand idle, they recorded particles of cosmic rays penetrating to them under the ground to a depth of about 100 m. The flux of such particles consists of muons, which slightly interact with the su ... Read more