The Large Hadron Collider has helped staff spot two previously unseen particles. Both are known as baryons and are made up of three quarks.

The two baryons have the somewhat uncatchy names of  Xi_b’^– and Xi_b*^–. The existence of both had previously been predicted by the quark model, but they had yet to be seen in reality. Both have around six times the mass of a proton.

According to CERN’s Dr Patrick Koppenberg, ongoing analysis of data collected from the Large Hadron Collider helps identify an average of five particles a year, but it’s very rare to make two such discoveries at the same time. Being able to identify both the mass of the two baryons and their spin (the two have opposite spins to one another) will help scientists continue to narrow the range of known ways in which quarks can be (and are) arranged to form particles.

(Image credit: Julian Herzog via Creative Commons license)