d ^∗ (2380) and its partners in a diquark model

The purpose of the present study was to explore the possibility of accommodating the d ^∗ (2380) and its flavor SU(3) partners in a diquark model. Proposing that d ^∗ (2380) is composed of three vector diquarks, its mass is calculated by use of an effective Hamiltonian approach and its decay width is estimated by considering the effects of quark tunneling from one diquark to the others and the decays of the subsequent two-baryon bound state. Both the obtained mass and decay width of d ^∗ (2380) are in agreement with the experimental data, with the unexpected narrow decay width being naturally explained by the large tunneling suppression of a quark between a pair of diquarks. The masses and decay widths of the flavor SU(3) partners of d ^∗ (2380) are also predicated within the same diquark scenario.