[spxtr]

> The new particle contains two charm quarks and an up and a down antiquark. Several tetraquarks have been discovered in recent years (including one with two charm quarks and two charm antiquarks), but this is the first one that contains two charm quarks, without charm antiquarks to balance them.

This is not the first time a tetraquark has been measured, but instead it's the first time a tetraquark with two charm quarks and no charm antiquarks. That's still nice work, but I was initially confused by the headline ("didn't they discover those already?").

[lisper]

I read it as: "CERN has discovered a new particle, and that new particle is an instance of a known class of particles called tatraquarks". The wording is a little sloppy and ambiguous, but headlines are pretty tightly constrained so I'm willing to cut the writers a little slack on this. I've seen much worse.