The new pentaquarks in the diquark model

Pentaquark baryons are a natural expectation of an extended picture of hadrons where quarks and diquarks are the fundamental units. The parity/mass pattern observed, when compared to that of exotic mesons, appears as the footprint of a compact five-quark structure. What has been learned from the X, Y, Z phenomenology informs about the newly found pentaquark structure and suggests further experimental tests and directions to be explored.