Natura - nature actualia - actual entities Mundus Plinius - physical world particles hadrons - composite particles baryons - fermionic hadrons 1 N baryons - baryons with three u and/or d quarks (I=1/2) 2 Delta baryons - baryons with three u and/or d quarks (I=3/2) 3 Lambda baryons - baryons with two u and/or d quarks (I=0) 4 Sigma baryons - baryons with two u and/or d quarks (I=1) 5 Xi baryons - baryons with one u or d quark (I=1/2) 6 Omega baryons - baryons with no u or d quarks (I=0) 7 charmed baryons 8 "doubly charmed baryons" [unconfirmed] 9 bottom baryons