Semileptonic ${\mathrm{\Lambda }}_b\to {\overline{\nu }}_{l}l{\mathrm{\Lambda }}_c(2595)$ and ${\mathrm{\Lambda }}_b\to {\overline{\nu }}_{l}l{\mathrm{\Lambda }}_c(2625)$ decays in the molecular picture of ${\mathrm{\Lambda }}_c(2595)$ and ${\mathrm{\Lambda }}_c(2625)$

We evaluate the partial decay widths for the semileptonic ${\mathrm{\Lambda }}_b\to {\overline{\nu }}_{l}l{\mathrm{\Lambda }}_c(2595)$ and ${\mathrm{\Lambda }}_b\to {\overline{\nu }}_{l}l{\mathrm{\Lambda }}_c(2625)$ decays from the perspective that these two ${\mathrm{\Lambda }}_c^{*}$ resonances are dynamically generated from the $DN$ and $D^{*}N$ interaction with coupled channels. We find that the ratio of the rates obtained for these two reactions is compatible with present experimental data and is very sensitive to the $D^{*}N$ coupling, which becomes essential to obtain agreement with experiment. Together with the results obtained for the ${\mathrm{\Lambda }}_b\to {\pi }^{-}{\mathrm{\Lambda }}_c^{*}$ reactions, it gives strong support to the molecular picture of the two ${\mathrm{\Lambda }}_c^{*}$ resonances and the important role of the $D^{*}N$ component neglected in prior studies of the ${\mathrm{\Lambda }}_c(2595)$ from the molecular perspective.

Figure 1

Diagrammatic representation of the ${\mathrm{\Lambda }}_b\to (l{\overline{\nu }}_l){\mathrm{\Lambda }}_c^{*}$ decay.

Figure 2

Mechanism to produce a ${\mathrm{\Lambda }}_c^{*}$ resonance that is mostly made from $DN$, $D^{*}N$.

Figure 3

$\frac{\mathrm{d}\mathrm{\Gamma }}{\mathrm{d}{M}_{\mathrm{inv}}}$ for the $(\overline{\nu }l)$ pair as a function of $M_{\mathrm{inv}}(\overline{\nu }l)$ in the ${\mathrm{\Lambda }}_b\to {\overline{\nu }}_{l}l{\mathrm{\Lambda }}_c(2595)$ decay.