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

Understand

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.