Pentaquark ${\Theta }^{+},$ constituent quark structures, and prediction of charmed ${\Theta }_c^0$ and bottomed ${\Theta }_b^{+}$

The newly observed ${\Theta }^{+}$ resonance is believed to be a pentaquark with the constituent quarks $\mathrm{uudd}\overline{s}.$ There are a few options for the constituent quark structure. Some advocate diquark-diquark-antiquark $\mathrm{}\left(\mathrm{ud}\right)\mathrm{}-\mathrm{}\left(\mathrm{ud}\right)\mathrm{}-\overline{s}$ while others favor diquark-triquark $\mathrm{}\left(\mathrm{ud}\right)\mathrm{}-\left(ud\overline{s}\right)$ structure. We use the color-spin hyperfine interaction to examine the energy levels of these structures, and we find that the diquark-diquark-antiquark structure is slightly favored. We proceed to write down the flavor triplet and antisextet of the charmed or bottomed exotic baryons with internal $\mathrm{qqqq}\overline{Q}$ quarks. We also estimate the mass of ${\Theta }_c^0$ and ${\Theta }_b^{+}.$