Anticharmed Pentaquark from $B$ Decays

We explore the possibility of observing the anticharmed pentaquark state from the ${\Theta }_c\overline{n}{\pi }^{+}$ decay of $B$ mesons produced in $B$-factory experiments. We first show that the observed branching ratio of the $B^{+}$ to ${\Lambda }_c^{-}p{\pi }^{+}$, as well as its open histograms, can be remarkably well explained by assuming that the decay proceeds first through the ${\pi }^{+}{\overline{D}}^0$ (or ${\overline{D}}^{*0}$) decay, and then through the subsequent decay of the virtual ${\overline{D}}^0$ or ${\overline{D}}^{*0}$ mesons to ${\Lambda }_c^{-}p$. We then note that the ${\Theta }_c$ can be similarly produced when the virtual ${\overline{D}}^0$ or ${\overline{D}}^{*0}$ decay into an antinucleon and a ${\Theta }_c$. Combining the present theoretical estimates for the ratio $g_{DN{\Lambda }_c}/g_{DN{\Theta }_c}\sim 13$ and $g_{D^{*}N{\Theta }_c}\sim \frac{1}{3}{g}_{DN{\Theta }_c}$, we find that the anticharmed pentaquark ${\Theta }_c$, which was predicted to be bound by several model calculations, can be produced via $B^{+}\to {\Theta }_c\overline{n}{\pi }^{+}$, and be observed from the $B$-factory experiments through the weak decay of ${\Theta }_c\to p{K}^{+}{\pi }^{-}{\pi }^{-}$.

Figure 1

Hadronic description for the hadronic decay $B^{+}\to {\Lambda }_c\overline{p}{\pi }^{+}$.

Figure 2

Comparison of the experimental data [34] to the present calculation on the open histogram of the $B^{+}\to {\Lambda }_c^{-}p{\pi }^{+}$ decay as a function of $M({\Lambda }_c^{-}p)$, requiring $M({\Lambda }_c^{-}\pi )>2.6\mathrm{GeV}/c^2$ and $M(p{\pi }^{+})>1.6\mathrm{GeV}/c^2$.

Figure 3

Similar to Fig. 2, but as a function of $M(p{\pi }^{+})$, requiring $M({\Lambda }_c^{-}\pi )>2.6\mathrm{GeV}/c^2$ and $M({\Lambda }_c^{-}p)>3.5\mathrm{GeV}/c^2$.

Figure 4

Hadronic description for the hadronic decay $B^{+}\to {\Theta }_c\overline{n}{\pi }^{+}$.