Revisit the diquark of ${\Lambda }_c$ in the ${\Lambda }_c\to \Lambda K^{+}$ and ${\Lambda }_c\to {\Sigma }^0{K}^{+}$ processes

Abstract

The spatial distributions of $[ud]$ diquark and heavy-light diquark of the SU(3)-flavor antitriplet charmed baryons are investigated by the two singly Cabibbo-suppressed hadronic weak decays, ${\Lambda }_c\to \Lambda K^{+}$ and ${\Lambda }_c\to {\Sigma }^0{K}^{+}$ within the nonrelativistic constituent quark model. The above two spatial distributions are reflected by the two parameters ${\alpha }_{\rho }$ and ${\alpha }_{\lambda }$, which are the harmonic oscillator strength parameters of the charmed baryons. These two parameters obtain strong constraints from the decay widths of ${\Lambda }_c\to \Lambda K^{+}$ and ${\Lambda }_c\to {\Sigma }^0{K}^{+}$. The larger the harmonic oscillator parameter is, the more compact the spatial distribution will become. The current ${\alpha }_{\rho }$ and ${\alpha }_{\lambda }$ indicate that neither the light diquark nor the heavy-light diquark turns out to favor a compact structure. In addition, some selection rules, including the ``$\Lambda$ selection rule'', can be useful for the search of excited baryons in the heavy-flavor baryon hadronic weak decays.

14 pages, 4 figures