The LHC collides ions at new record energy
Geneva, 25 November 2015. After the successful restart of the Large Hadron Collider and its first months of data taking with proton collisions at a new energy frontier, the LHC is moving to a new phase, with the first lead-ion collisions of season 2 at an energy about twice as high as that of any previous collider experiment. Following a period of intense activity to re-configure the LHC and its chain of accelerators for heavy ion beams, CERN 's accelerator specialists put the beams into collision for the first time in the early morning of 17 November 2015 and 'stable beams' were declared at 10.59am today, marking the start of a one-month run with positively charged lead ions: lead atoms stripped of electrons. The four large LHC experiments will all take data over this campaign, including LHCb, which will record this kind of collision for the first time. Colliding lead ions allows the LHC experiments to study a state of matter that existed shortly after the big bang, reaching a temperature of several trillion degrees. "It is a tradition to collide ions over one month every year as part of our diverse research programme at the LHC," said CERN Director General Rolf Heuer. " This year however is special as we reach a new energy and will explore matter at an even earlier stage of our universe." Early in the life of our universe, for a few millionths of a second, matter was a very hot and very dense medium - a kind of primordial 'soup' of particles, mainly composed of fundamental particles known as quarks and gluons.
