$\Lambda_c N$ interaction from lattice QCD and its application to $\Lambda_c$ hypernuclei

TL;DR

This study uses lattice QCD to investigate the interaction between $\Lambda_c$ and nucleons, finding an attractive potential that suggests the possible existence of $\Lambda_c$ hypernuclei for atomic numbers $A \,\ge\, 12$, with implications for understanding charmed baryon interactions.

Contribution

The paper provides the first lattice QCD calculation of the $\\Lambda_c N$ interaction, including potentials and phase shifts, and predicts the formation of $\\Lambda_c$ hypernuclei for sufficiently large atomic numbers.

Findings

The $\\Lambda_c N$ interaction is attractive at low energies.

No two-body bound states are formed by $\\Lambda_c N$.

$\\Lambda_c$ hypernuclei can exist for $A \ge 12$ with a few MeV binding energy.

Abstract

The interaction between $\Lambda_c$ and a nucleon ($N$) is investigated by employing the HAL QCD method in the (2+1)-flavor lattice QCD on a $(2.9~\mathrm{fm})^3$ volume at $m_\pi \simeq 410,~570,~700$ MeV. We study the central potential in $^1S_0$ channel as well as central and tensor potentials in $^3S_1 - $$^3D_1$ channel, and find that the tensor potential for $\Lambda_c N$ is negligibly weak and central potentials in both $^1S_0$ and $^3S_1 - $$^3D_1$ channels are almost identical with each other except at short distances. Phase shifts and scattering lengths calculated with these potentials show that the interaction of $\Lambda_c N$ system is attractive and has a similar strength in $^1S_0$ and $^3S_1$ channels at low energies (i.e. the kinetic energy less than about $40$ MeV). While the attractions are not strong enough to form two-body bound states, our results lead to a possibility to form $\Lambda_c$ hypernuclei for sufficiently large atomic numbers ($A$). To demonstrate this, we derive a single-folding potential for $\Lambda_c$ hypernuclei from the $\Lambda_c$-nucleon potential obtained in lattice QCD, and find that $\Lambda_c$ hypernuclei can exist for $A \ge 12$ with the binding energies of a few MeV. We also estimate the Coulomb effect for the $\Lambda_c$ hypernuclei.