Lattice QCD study of $\Lambda_c \Lambda_c$ scattering

TL;DR

This study uses lattice QCD to analyze the near-threshold scattering of two Lambda_c baryons, providing the first such result and indicating a repulsive interaction with a specific scattering length.

Contribution

First lattice QCD calculation of near-threshold Lambda_c Lambda_c scattering, using finite volume methods and specific ensembles, with detailed analysis of interaction characteristics.

Findings

Interaction is repulsive in the Lambda_c Lambda_c channel.

Scattering length determined as -0.21(4)(8) fm.

No mixing observed with Xi_cc N channel.

Abstract

We present the first lattice result of the near threshold $\Lambda_c\Lambda_c$ scattering with $I(J^P) = 0(0^+)$. The calculation is performed on two $N_f = 2+1$ Wilson-Clover ensembles with pion mass $m_\pi \sim 303$\,MeV and lattice spacing $a = 0.07746$\,fm. The L\"uscher's finite volume method is utilized to extract the scattering parameters from the finite-volume spectrum. The coupled channel $\Xi_{cc}N$ is ignored in the scattering analysis based on the observation that the energy levels computed from the $\Lambda_c\Lambda_c$ and $\Xi_{cc}N$ operators do not mix. The $\Sigma_c\Sigma_c$ channel is not included either since the energy range explored in this study is well below its threshold. Our results indicate that the interaction in the $\Lambda_c\Lambda_c$ single channel is repulsive, and the scattering length is determined to be $a_0 = -0.21(4)(8)$\,fm, where the first error is the statistical error and the second is the systematic error.