2025/05/27 by Wang, Y. L., Hsiao, Y. K.
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2505.21311
Using the topological-diagram approach based on SU(3) flavor symmetry, we investigate two-body Λc+→ \bf BS decays, where Λc+ is a member of the anti-triplet charmed baryons (\bf Bc), \bf B denotes a final-state baryon, and S refers to a light scalar meson, such as f0/f0(980), a0/a0(980), σ0/f0(500), or κ/K0^*(700). Our analysis demonstrates that short-distance contributions, represented by the topological amplitudes, play a dominant role in these decays. In particular, this framework naturally accounts for the experimentally observed branching ratio \cal B(Λc+ → Λa0+), which exceeds predictions based solely on long-distance effects by an order of magnitude. Considering the light scalar mesons as tentraquark states, we predict \cal B(Λc+→ p f0,pσ0) =(1.7± 0.6,0.02±0.01)× 10-3 and \cal B(Λc+→ Σ+ f0,Σ+ σ0) =(0.7± 0.5, 1.5± 0.7)× 10-2. In addition, the decay Λc+ → Ξ0 κ+, which proceeds via a single W-exchange diagram, is found to have a branching fraction of (4.9 ± 0.9) × 10-2. These results suggest that the branching ratios of \bf Bc → \bf B S are generally comparable to those of \bf Bc → \bf BM, where M denotes a pseudoscalar meson. The predicted rates are sufficiently large to be probed in current experiments at BESIII, Belle II, and LHCb, offering promising opportunities to explore the internal structure of light scalar mesons.