Dynamical calculation of theΔΔdibaryon candidates

Abstract

We perform a dynamical calculation of the ∆∆ dibaryon candidates with IJ P = 03 + and IJ P = 30 + in the framework of two constituent quark models: the quark delocalization color screening model and the chiral quark model. Our results show that the dibaryon resonances with IJ P = 03 + and IJ P = 30 + can be formed in both models. The mass and width of IJ P = 03 + state are smaller than that of IJ P = 30 + state due to the one-gluon-exchange interaction between quarks. The resonance mass and decay width of IJ P = 03 + state in both models agree with that of the recent observed resonance in the reaction pn → dπ 0 π 0 . The IJ P = 30 + ∆∆ is another dibaryon candidate with smaller binding energy and larger width. The hidden-color channel coupling is added to the chiral quark model, and we find it can lower the mass of the dibaryons by 10-20 MeV.

Examination of the nature of the ABC effect

“…This is in accordance with meanwhile numerous theoretical work about this resonance [29][30][31][32][33][34][35][36][37][38][39]. It also is in agreement with the measured branchings of the d * decay into the diverse N N ππ channels [40].…”

Recent Results from WASA-at-COSY

“…The Los Alamos theory group [36] originally predicted its mass to be lower by as much as 200 MeV. However, its recent calculations [37] agree with the experimental value. Another real prediction of this state at the proper mass is from Z. Y. Zhang et.al.…”

Resonances at COSY — the dibaryon issue

“…However, initially they predicted an enormous binding energy as large as 350 MeV for such a state. Only recently -after the experimental observation -the calculations of this group approached the experimental value [57].…”