Theorists perplexed by hints of unexpected new particle

Hundreds of papers attempt explanation for surprising LHC data

illustration of proton collision

NEW LIGHT A possible new particle shows up in proton collisions at the Large Hadron Collider that produce two photons, as in an event (illustrated here) seen by the CMS detector.

CMS/CERN

Physicists may soon know if a potential new subatomic particle is something beyond their wildest dreams — or if it exists at all.