Final-state rescattering mechanism of charmed baryon decays

TL;DR

This paper introduces a final-state rescattering mechanism to comprehensively analyze charmed baryon decays, successfully explaining experimental data and providing insights into CP violation with reduced uncertainties.

Contribution

It develops a novel approach using loop integrals for long-distance effects, enabling complete calculation of decay amplitudes and strong phases in charmed baryon decays.

Findings

All nine experimental branching fractions are explained with one parameter.

Decay asymmetries and CP violations are insensitive to the model parameter.

The method provides a complete calculation of both real and imaginary parts of decay amplitudes.

Abstract

The dynamical studies on the non-leptonic weak decays of charmed baryons are always challenging, due to the large non-perturbative contributions at the charm scale. In this work, we develop the final-state rescattering mechanism to study the two-body non-leptonic decays of charmed baryons. The final-state interaction is a physical picture of long-distance effects. Instead of using the Cutkosky rule to calculate the hadronic triangle diagrams which can only provide the imaginary part of decay amplitudes, we point out that the loop integral is more appropriate, as both the real parts and the imaginary parts of amplitudes can be calculated completely. In this way, it can be obtained for the non-trivial strong phases which are essential to calculate CP violations. With the physical picture of long-distance effects and the reasonable method of calculations, it is amazingly achieved that all the nine existing experimental data of branching fractions for the $\Lambda_c^+$ decays into an octet light baryon and a vector meson can be explained by only one parameter of the model. Besides, the decay asymmetries and CP violations are not sensitive to the model parameter, since the dependence on the parameter is mainly cancelled in the ratios, so that the theoretical uncertainties on these observables are lowered down.