Heavy pentaquark spectroscopy in the diquark model

QQ'qq (q) over bar pentaquarks are studied in a potential model, under the hypothesis that they are composite objects of two diquarks and one antiquark. The interaction between two colored objects includes two contributions, one based on the q (q) over bar potential in QCD, computed in the gauge/string duality approach, and another describing the spin-spin interaction. The model has been extended to investigate pentaquarks with different quark content, as Qqqq (q) over bar and Qqqq (Q) over bar, the latter including the states observed by LHCb, P-c(4380)(+) and P-c(4450)(+), later updated, with a new data sample, to P-c(4312)(+), P-c(4440)(+), and P-c(4457)(+).