W-exchange contribution to the decays $\Xi_{cc}^{++}\to\Xi_{c}^{+(\prime)}\pi^{+}$ using light-cone sum rules

TL;DR

This paper calculates the W-exchange contribution to specific doubly charmed baryon decays using light-cone sum rules, providing theoretical predictions that align well with experimental data.

Contribution

It introduces a light-cone sum rule approach to evaluate W-exchange effects in $ ext{Xi}_{cc}^{++}$ decays, enhancing understanding of non-factorizable contributions.

Findings

The decay branching ratio ${ m B}( ext{Xi}_{cc}^{++} o ext{Xi}_c^{+ ext{'}} ext{pi}^+)$ to ${ m B}( ext{Xi}_{cc}^{++} o ext{Xi}_c^+ ext{pi}^+)$ is predicted as 1.42±0.78.

The theoretical ratio agrees with the experimental value of 1.41±0.17±0.1.

W-exchange contributions are significant in understanding these decay processes.

Abstract

We calculate the W-exchange contribution to the $\Xi_{cc}^{++}\to\Xi_{c}^{+(\prime)}\pi^{+}$ decay using light-cone sum rules. The two-particle light-cone distribution amplitudes of the pion are used as non-perturbative input for the sum rules calculation, and the perturbative kernel is calculated at the leading order. We obtain the corresponding decay branching fractions by combining our W-exchange amplitudes with the factorizable amplitudes given by various theoretical methods from the literature. It is shown that with the factorizable amplitudes from heavy quark effective theory, we obtain the branching fraction ratio ${\cal B}(\Xi_{cc}^{++}\to\Xi_{c}^{+\prime}\pi^{+})/{\cal B}(\Xi_{cc}^{++}\to\Xi_{c}^{+}\pi^{+})= 1.42\pm 0.78$, which is consistent with the experimental value of $1.41\pm 0.17\pm 0.1$.