Previously, Skwarnicki said, it wasn't clear how the five quarks
were arranged inside the pentaquark.
In the 1960s, when physicists were first theorizing about all of these quarks, they realized that there was no
reason not to have particles made of four or five quarks, Skwarnicki told Live Science.
But there hadn't been experimental evidence of five-quark particles, or pentaquarks- that is, until 2015,
when Skwarnicki and his colleagues discovered the objects among the particles created
by collisions in the Large Hadron Collider in Geneva.