${\Xi }_c\to \Xi$ Semileptonic Decays: An LCSR View on the Experiment-Lattice Tension

Abstract

We present a light-cone QCD sum rule analysis of the semileptonic decays of ${\Xi }_c$ baryons, focusing on the channels ${\Xi }_c^0\to {\Xi }^{-}{\ell }^{+}{\nu }_{\ell }$, and ${\Xi }_c^{+}\to {\Xi }^0{\ell }^{+}{\nu }_{\ell }$. The transition form factors are calculated within the light-cone QCD sum rules framework, using the distribution amplitudes of the heavy ${\Xi }_c$ baryons. The obtained form factors are then used to compute the differential and total decay widths, as well as the branching fractions. Our numerical results for the branching fractions are $\mathcal{B}({\Xi }_c^0\to {\Xi }^{-}{\ell }^{+}{\nu }_{\ell })=(3.73\pm 1.04)\%$ , $\mathcal{B}({\Xi }_c^0\to {\Xi }^{-}{\mu }^{+}{\nu }_{\mu })=(3.59\pm 1.01)\%$, $\mathcal{B}({\Xi }_c^{+}\to {\Xi }^0{\ell }^{+}{\nu }_{\ell })=(11.2\pm 3.25)\%$, and $\mathcal{B}({\Xi }_c^{+}\to {\Xi }^0{\mu }^{+}{\nu }_{\mu })=(10.8\pm 3.13)\%$. These results are in good agreement with recent lattice QCD calculations, while being larger than the current experimental measurements and differing from the predictions of other theoretical approaches.

Comments: Typos in formulas are corrected