Search for doubly charmed baryons ${\Xi }_{cc}^{+}$ and ${\Xi }_{cc}^{++}$ in BABAR

We search for the production of doubly charmed baryons in $e^{+}{e}^{-}$ annihilations at or near a center-of-mass energy of 10.58 GeV, in a data sample with an integrated luminosity of $232{\mathrm{fb}}^{-1}$ recorded with the BABAR detector at the PEP-II storage ring at the Stanford Linear Accelerator Center. We search for ${\Xi }_{cc}^{+}$ baryons in the final states ${\Lambda }_c^{+}{K}^{-}{\pi }^{+}$ and ${\Xi }_c^0{\pi }^{+}$, and ${\Xi }_{cc}^{++}$ baryons in the final states ${\Lambda }_c^{+}{K}^{-}{\pi }^{+}{\pi }^{+}$ and ${\Xi }_c^0{\pi }^{+}{\pi }^{+}$. We find no evidence for the production of doubly charmed baryons.

Figure 1

Distributions of the mass difference $\Delta M({\Xi }_{cc}-{\Lambda }_c^{+})$ for (a,b) ${\Xi }_{cc}^{+}$ and (c,d) ${\Xi }_{cc}^{++}$ candidates with (a,c) no $p^{*}$ requirement and (b,d) $p^{*}>2.3\mathrm{GeV}/c$. Data points with error bars correspond to candidates near the ${\Lambda }_c^{+}$ mass: $2281<M({\Lambda }_c^{+})<2291\mathrm{MeV}/c^2$. Shaded histograms correspond to candidates in $M({\Lambda }_c^{+})$ sidebands ($2256<M({\Lambda }_c^{+})<2281\mathrm{MeV}/c^2$ and $2291<M({\Lambda }_c^{+})<2316\mathrm{MeV}/c^2$), scaled to represent the expected amount of non-${\Lambda }_c^{+}$ background in the data projections.

Figure 2

Distributions of the mass difference $\Delta M({\Xi }_{cc}-{\Xi }_c^0)$ for (a,b) ${\Xi }_{cc}^{+}$ and (c,d) ${\Xi }_{cc}^{++}$ candidates with (a,c) no $p^{*}$ requirement and (b,d) $p^{*}>2.0\mathrm{GeV}/c$. Data points with error bars correspond to ${\Xi }_{cc}$ candidates reconstructed using ${\Xi }_c^0$ candidates near the ${\Xi }_c^0$ mass, $2457<M({\Xi }_c^0)<2485\mathrm{MeV}/c^2$; the shaded histograms correspond to $M({\Xi }_c^0)$ sidebands ($2451<M({\Xi }_c^0)<2457\mathrm{MeV}/c^2$ and $2487<M({\Xi }_c^0)<2501\mathrm{MeV}/c^2$) scaled to represent the expected amount of non-${\Xi }_c^0$ background in the $M({\Xi }_c^0)$ signal region.