Heptaquark

In particle physics, heptaquarks are a family of hypothetical composite particles, each consisting of seven quarks or antiquarks of any flavours.

Properties
One model predicts that the lowest-energy heptaquark state would be a spin-1/2 or spin-3/2 state of energy roughly 2.5 GeV. Another study found that the most stable heptaquark would include three strange quarks and two strange antiquarks.