# Ab initio three-loop calculation of the W-exchange contribution to nonleptonic decays of double charm baryons

## TL;DR

This paper presents a detailed three-loop quark model calculation of the W-exchange contribution to nonleptonic decays of doubly charmed baryons, providing insights into decay mechanisms beyond factorizable contributions.

## Contribution

It introduces an ab initio three-loop calculation of W-exchange effects in doubly charmed baryon decays using a covariant confined quark model, advancing theoretical precision.

## Key findings

- W-exchange contributions are significant and comparable to tree-level contributions.
- Calculated decay widths align with some existing theoretical models.
- Quantitative analysis of helicity amplitudes for decay processes.

## Abstract

We have made an ab initio three-loop quark model calculation of the $W$-exchange contribution to the nonleptonic two-body decays of the doubly charmed baryons $\Xi_{cc}^{++}$ and $\Omega_{cc}^{+}$. The $W$-exchange contributions appear in addition to the factorizable tree graph contributions and are not suppressed in general. We make use of the covariant confined quark model previously developed by us to calculate the tree graph as well as the $W$-exchange contribution. We calculate helicity amplitudes and quantitatively compare the tree graph and $W$-exchange contributions. Finally, we compare the calculated decay widths with those from other theoretical approaches when they are available.