* Astronomy

LHC sees hint of boson heavier than Higgs

The two experiments that discovered the Higgs boson in 2012 have sensed an intriguing if very preliminary whiff of a possible new elementary particle. Both collaborations announced their observations on 15 December, as they released their first significant results since completing a major upgrade earlier this year.
The results largely matched a rumour that has circulated on social media and blogs for several days: that both the CMS and ATLAS detectors at the Large Hadron Collider (LHC) outside Geneva, Switzerland, have seen in the debris of proton-proton collisions an unexpected excess of pairs of photons carrying around 750 giga electronvolts (GeV) of energy each. This could be a tell-tale sign of a new particle - also a boson, but not necessarily similar to the Higgs - weighing the equivalent of around 1,500 GeV and decaying into two photons of equal mass. It would be nearly nine times more massive than the next heaviest particle discovered so far, the top quark, and a dozen times more massive than the Higgs.
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