The Large Hadron Collider has been back online and pushing the limits of physics again for a few months now. But it's about to enter a new phase, colliding lead ions at twice the energy that any collider has ever achieved in the past.
The equipment at the LHC was readied for the new collisions on November 17, but yesterday scientists confirmed that they'd created stable beams that were ready for use in experiments. Now, all four of the LHC's detectors will take part in analysing what happens when lead ions slam into each other.
Colliding lead ions — the normal metal atoms, just stripped of electrons — isn't a new idea. When they collide, they create a quark and gluon plasma that resembles the kind of matter that would have been present just after the Big Bang. But colliding them at the kinds of energies that the LHC can now achieve — where temperatures are set to reach several trillion degrees — will allow the physicists to see a greater volume than ever of the matter.
In a press release, Paolo Giubellino from the LHC explained what the scientists are eager to learn about when they look at it:
"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. For instance, we are eager to learn how the increase in energy will affect charmonium production, and to probe heavy flavour and jet quenching with higher statistics. The whole collaboration is enthusiastically preparing for a new journey of discovery."
Just exactly what the the researchers will find out, then, remains somewhat of a mystery. But, like some of the quarks that the researchers will be studying, therein lies the charm.
Image by CERN