Analysis of the semileptonic decays of $\hat{I}{ž}_{cc}$ and $\hat{I}{\text{c◯}}_{cc}$ baryons in QCD sum rules

Abstract

We firstly carry out a systematic analysis on the spin ${\frac{1}{2}}^{+}\to {\frac{3}{2}}^{+}$ weak transition process in the framework of three-point QCD sum rules, where the initial and final states are doubly and singly charmed baryons. In the phenomenological side, all possible couplings of interpolating current to hadronic states are considered. In doing operator production expansion at QCD side, the contributions of the perturbative part, vacuum condensate terms of $⟨\bar{q}q⟩$, $⟨g_s^{2}GG⟩$, $⟨\bar{q}{g}_s\ddot{I}ƒGq⟩$ and $g_s^2⟨\bar{q}q{⟩}^2$ are all considered. After the form factors in space-like region ($Q^2>0$) are obtained, the numerical results are extrapolated into time-like region ($Q^2<0$) by a fitting function. Using the predicted form factors, we finally analyze the semileptonic decays of $\hat{I}{ž}_{cc}^{++}\to \hat{I}{\pounds }_c^{\ast +}{l}^{+}\hat{I}{½}_l$, $\hat{I}{ž}_{cc}^{++}\to \hat{I}{ž}_c^{\prime \ast +}{l}^{+}\hat{I}{½}_l$, $\hat{I}{\text{c◯}}_{cc}^{+}\to \hat{I}{ž}_c^{\prime \ast 0}{l}^{+}\hat{I}{½}_l$ and $\hat{I}{\text{c◯}}_{cc}^{+}\to \hat{I}{\text{c◯}}_c^{\ast 0}{l}^{+}\hat{I}{½}_l$ with $l=e,\hat{I}¼$. The predictions in this work can deepen our understanding of the dynamics in the decay processes of doubly heavy baryons and provide useful information to explore the possibility of new physics in heavy baryonic decay channels.