Branching ratios for the decay of d*(2380)

Abstract

We calculate the charge distributions of d * (2380). Two different interpretations of the d * are considered for a comparison. One is a compact explanation with coupled ∆∆ + CC two-channel approximation in the chiral constituent quark model. Another is a resonance state of D12π. The remarkable differences of the charge distributions in the two pictures are shown and it is expected that the future experiments may provide a clear test for the different theoretical interpretations.

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].…”

“…[40]. There also the experimentally extracted partial widths Γ i (s = m 2 R ) and Γ f (s = m 2 R ) are given and can be deduced, respectively, from the quoted partial cross sections at resonance.…”

Recent Results from WASA-at-COSY

“…The observed d * decay branchings into the diverse two-pion channels are consistent with expectations from isospin decomposition [28] as well as explicit theoretical calculations [29][30][31].…”

“…From the knowledge of the resonance contributions to the various two-pion production channels the expected resonance contribution to elastic np scattering has been estimated [28] to be in the order of about 170 µb. This number has to be compared to a total np cross section of nearly 40 mb.…”

Dibaryons at COSY

“…All the data [4,5,[7][8][9][10][11] collected so far suggest that in 88 percent of cases d * decays into ∆∆ and in 12% to pn [18,19]. It can be further specified that 90% of the pn decays proceed via 3 D 3 partial wave (angular momentum L = 2 between nucleons) and 10% via 3 G 3 partial wave (L = 4) [4,5].…”