First search for the weak radiative decays $\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^{+}{\hat{I}}^3$ and $\hat{I}{ž}_c^0\to \hat{I}{ž}^0{\hat{I}}^3$

Abstract

We present the first search for the weak radiative decays $\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^{+}{\hat{I}}^3$ and $\hat{I}{ž}_c^0\to \hat{I}{ž}^0{\hat{I}}^3$ using a data sample of 980~fb${}^{-1}$ collected by the Belle detector operating at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. There are no evident $\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^{+}{\hat{I}}^3$ or $\hat{I}{ž}_c^0\to \hat{I}{ž}^0{\hat{I}}^3$ signals. Taking the decays $\hat{I}{›}_c^{+}\to p{K}^{-}\ddot{I}{€}^{+}$ and $\hat{I}{ž}_c^0\to \hat{I}{ž}^{-}\ddot{I}{€}^{+}$ as normalization channels, the upper limits at 90\% credibility level on the ratios of branching fractions $\mathcal{B}(\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^{+}{\hat{I}}^3)/\mathcal{B}(\hat{I}{›}_c^{+}\to p{K}^{-}\ddot{I}{€}^{+})<4.0\times 10^{-3}$ and $\mathcal{B}(\hat{I}{ž}_c^0\to \hat{I}{ž}^0{\hat{I}}^3)/\mathcal{B}(\hat{I}{ž}_c^0\to \hat{I}{ž}^{-}\ddot{I}{€}^{+})<1.2\times 10^{-2}$ are determined. We obtain the upper limits at 90\% credibility level on the absolute branching fractions $\mathcal{B}(\hat{I}{›}_c^{+}\to \hat{I}{\pounds }^{+}{\hat{I}}^3)<2.6\times 10^{-4}$ and $\mathcal{B}(\hat{I}{ž}_c^0\to \hat{I}{ž}^0{\hat{I}}^3)<1.8\times 10^{-4}$.

10 pages, 6 pages; accepted for publication as a Regular Article in Physical Review D