Starts With A Bang

Could no new particles at the LHC be exactly what physics needs? (Synopsis)

The ATLAS and CMS diphoton bumps, displayed together, clearly correlating at ~750 GeV. Image credit: CERN, CMS/ATLAS collaborations, image generated by Matt Strassler at https://profmattstrassler.com/2015/12/16/is-this-the-beginning-of-the-end-of-the-standard-model/.

“We have made the discovery of a new particle – a completely new particle – which is most probably very different from all the other particles. It’s nearly a once in a lifetime experience, I would say.” – Rolf-Dieter Heuer

At the end of its second, high-energy run, the Large Hadron Collider appeared to display evidence that perhaps a new particle existed at an energy of 750 GeV. The excess of twin photons produced at that energy appeared in both the ATLAS and CMS detectors, and might indicate the first particle beyond the standard model.

The Standard Model particles and their supersymmetric counterparts. Exactly 50% of these particles have been discovered, and 50% have never showed a trace that they exist. Image credit: Claire David, of http://davidc.web.cern.ch/davidc/index.php?id=research.

It might also be a little-understood feature of the standard model itself, or — perhaps most likely — it may be merely statistical noise. But perhaps the ‘nightmare scenario’ of no new particles is exactly what physics needs, to divert us away from the dead ends of naturalness, elegance, unification and greater and greater symmetries, which have borne no experimental fruits in more than 40 years.

Inside the magnet upgrades on the LHC, that have it running at nearly double the energies of the first (2010-2013) run. Image credit: Richard Juilliart/AFP/Getty Images.

Go and read this wonderful take from Sabine Hossenfelder about why the nightmare scenario might be a real dream-come-true after all!