“Try turning it off and on again” is a common piece of tech advice, but when you are dealing with the world’s biggest machine, things aren’t so simple.
Researchers at CERN near Geneva are getting ready to reboot the Large Hadron Collider, which was shut down in February 2013 to prepare it for colliding beams of protons at higher energies. The full switch-on is set for May 2015.
The LHC has performed well so far: in 2012 it discovered the Higgs boson, the last missing piece of the standard model of particle physics. But as the reboot approaches, some physicists worry that their machine won’t find anything else.
We know that the standard model is an incomplete description of the universe – it has nothing to say about gravity, for example. So there must be a more all-encompassing theory out there. It was hoped that the Higgs might have a few personality quirks to point physicists in the right direction, but it is looking more and more like the bog-standard version the standard model predicts.
One of the standard model’s leading competitors is a theory called supersymmetry, or SUSY, which posits the existence of a heavier partner for all of the standard particles. But no such particles have yet turned up.
If running at higher energies fails to find any superpartners, it will leave physicists with a multibillion dollar dilemma: should they build a successor to the LHC, capable of higher-energy collisions that might reveal SUSY? Or should they abandon SUSY in favour of something new? With no particles to show theoreticians the way, that decision won’t be easy, and no amount of switching the LHC off and on again will help.
This article appeared in print under the headline “2015 Preview: Rebooting the particle smasher”
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