SU(3) symmetry analysis in charmed baryon two body decays with penguin diagram contribution

TL;DR

This paper performs a SU(3) symmetry analysis of charmed baryon two-body decays, including penguin diagram contributions, to better understand decay amplitudes and CP violation with current experimental data.

Contribution

It introduces a global analysis incorporating penguin diagrams and reduces amplitude parameters using the KPW theorem, providing new insights into decay contributions and CP violation predictions.

Findings

Penguin diagram contributions are comparable to tree-level amplitudes.

Excluding certain data improves fit quality significantly.

Large uncertainties hinder precise determination of penguin effects.

Abstract

An increasing number of experimental measurements from the BESIII, Belle, and Belle-II collaborations encourage investigations into charmed baryon two-body decay processes. By including contributions from the penguin diagrams that are ignored in previous studies, we perform a global analysis with SU(3) flavor symmetry. Assuming all form factors are real, we achieve a remarkable minimal $\chi^{2}/d.o.f = 0.788$ and find that the contribution of the amplitude proportional to $V_{cb}^*V_{ub}$ is of the order $\sim 0.01$, comparable with the contribution of the tree-level diagram. Additionally, by using the KPW theorem to reduce the number of amplitudes from 13 to 7 in the leading contribution, it becomes possible to consider the complex form factor case for the leading IRA amplitude in the global analysis. However, the analysis of complex form factors significantly conflicts with the experimental data $Br(\Xi_c^0\to\Xi^-\pi^+)$, and by excluding this data, $\chi^2/d.o.f$ is reduced from 5.95 to 1.19. Although the analysis of complex form factors shows a significant central value of the penguin diagram contribution, the large errors from the corresponding form factors make it a challenge to precisely determine its true contribution. Consequently, the direct CP violation in decay processes is predicted to be approximately zero. With more data in future experiments, the penguin diagram contribution with the amplitude proportional to $V_{cb}^*V_{ub}$ will be precisely determined, allowing for a more accurate prediction of CP violation. Our analysis necessitates further theoretical investigations and experimental measurements in the future.