Not only is the Large Hadron Collider (LHC) at CERN one of the most ambitious experimental facilities in human history, it is also one of the most successful. Most famously responsible for revealing the existence of the elusive Higgs boson, it seems to regularly discover particles that defy the Standard Model of particle physics through its awesome particle collisions. This week, CERN announced that the LHC has collided energetically charged particles (ions) at a new record energy.
After the successful restarting of the LHC this year, and following on from its first few months of taking data from proton-proton collisions, the facility is moving on to a new phase which will fire lead ions into each other at incredible speeds. After an intense period of careful reconfiguration, stable beams of positively charged lead ions were declared on November 25, marking the first collision of a month-long experiment from which all four major segments of the LHC will be taking data.
The energies released in each collision will be at least double that of any previous collision, producing temperatures reaching several trillion degrees. The purpose of colliding lead ions will be to investigate a state of matter that came into existence shortly after the Big Bang, one of several existing in a cosmic “primordial soup” containing mostly quarks (which constitute the smaller particles of larger elementary particles like electrons) and gluons (which “glue” particles like the quarks together).
ALICE – A Large Ion Collider Experiment – is one of the major components of the LHC, and will be directly involved during this new phase of lead ion collision. “There are many very dense and very hot questions to be addressed with the ion run for which our experiment was specifically designed and further improved during the shutdown,” said ALICE collaboration spokesperson Paolo Giubellino in a statement. “The whole collaboration is enthusiastically preparing for a new journey of discovery.”
Image credit: Collision between lead ions within ALICE. CERN
Increasing the energy of the lead ion collisions will serve to increase both the temperature and volume of the resulting quark and gluon plasma. This will allow researchers to probe the strongly-interacting, energetic soup of particles in an unprecedented way, hopefully producing particle interactions not previously observed.
The LHCb collaboration will join the group of experiments taking data from ion-ion collisions for the very first time. “This is an exciting step into the unknown for LHCb, which has very precise particle identification capabilities. Our detector will enable us to perform measurements that are highly complementary to those of our friends elsewhere around the ring,” said LHCb collaboration spokesperson Guy Wilkinson in a statement.
Image credit: Collisions seen within the LHCb detector. CERN
The LHCb, or the Large Hadron Collider beauty experiment, is named after a family of fundamental particles called “beauty quarks”; it is designed to detect these in the aftermath of powerful collisions, along with their counterparts, the “anti-beauty” quarks. Comparing these quarks will provide physicists with useful clues as to why there is an imbalance in the amount of matter and antimatter in our universe, and the higher energies of these new collisions will aim to shed additional light on this long-standing mystery.