Nature recalls the discovery of an extremely rare 4 quark particle, amusingly named the "Tetraqaurk"
Unlike our well known cuddly 2 quark Mesons and 3 quark Baryons these new boys on the block probably only existed at the time of the bang bang itself.
The picture here shows the arrangement is similar, but different to a Two meson "molecule". I wonder if this is officially a Hadron?
For full details of this fascinating article go to http://www.nature.com/news/quark-quartet-opens-fresh-vista-on-matter-1.13225