2025/12/11 by Cao, Ye, Duan, Ming-Xiao, Tao, Zhong +1
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #Nuclear Theory (nucl-th)
paper · doi:10.48550/arxiv.2512.10346
We provide a unified approach for the two-body hadronic weak decays of hyperons with S=-1, i.e. Λ and Σ^±, in the framework of the non-relativistic constitute quark model (NRCQM). A combined analysis shows that the branching ratios and asymmetry parameters of the decay channels Λ→ pπ- and Σ^±→ Nπ can be well described in the same framework with the direct pion emission, color suppressed internal W emission, and pole terms included. However, the channel Λ→ nπ0 indicates significant deviations from the experimental data based on these mentioned transition mechanism. We demonstrate that the final state interactions (FSIs) via the coupled-channel rescatterings play a crucial role in Λ→ nπ0. Namely, the dominant decay channel of Λ→ pπ- can contribute to Λ→ nπ0 via the pπ-→ nπ0 rescatterings. This is a leading correction effect for Λ→ nπ0 at the one-loop level. We find that such FSIs only become the leading effects in Λ→ nπ0, but contribute as subleading contributions in other channels. We also demonstrate that the pole terms are indispensable in these hyperon decays. In particular, for Σ-→ nπ- and Σ+→ nπ+, it shows that Λ(1405) as the intermediate state in the pole term amplitude is necessary for reproducing the experimental data. We also find that a dynamic selection rule forbids the radial excitation state N(1710) of the quark model multiplet |70, 28,2,0+,1/2+⟩ from contribution. To some extent, the hyperon hadronic weak decays serve as a special probe for the underlying transition mechanisms and can provide some constraints on the intermediate JP=1/2^± baryon resonances.