The meson-exchange model for the $\Lambda\bar{\Lambda}$ interaction

TL;DR

This study uses the one-boson-exchange potential model to explore whether the particles Y(2175) and η(2225) can be interpreted as bound states of Lambda-antiLambda pairs, considering various meson exchanges.

Contribution

It applies the OBEP model to analyze Lambda-antiLambda interactions and suggests possible bound state interpretations for Y(2175) and η(2225).

Findings

Y(2175) may be a Lambda-antiLambda bound state in the ^3S_1 channel.

η(2225) may be a Lambda-antiLambda bound state in the ^1S_0 channel.

The results are sensitive to the cutoff parameters of meson exchanges.

Abstract

In the present work, we apply the one-boson-exchange potential (OBEP) model to investigate the possibility of Y(2175) and $\eta(2225)$ as bound states of $\Lambda\bar{\Lambda}(^3S_1)$ and $\Lambda\bar{\Lambda}(^1S_0)$ respectively. We consider the effective potential from the pseudoscalar $\eta$-exchange and $\eta^{'}$-exchange, the scalar $\sigma$-exchange, and the vector $\omega$-exchange and $\phi$-exchange. The $\eta$ and $\eta^{'}$ meson exchange potential is repulsive force for the state $^1S_0$ and attractive for $^3S_1$. The results depend very sensitively on the cutoff parameter of the $\omega$-exchange ($\Lambda_{\omega}$) and least sensitively on that of the $\phi$-exchange ($\Lambda_{\phi}$). Our result suggests the possible interpretation of Y(2175) and $\eta(2225)$ as the bound states of $\Lambda\bar{\Lambda}(^3S_1)$ and $\Lambda\bar{\Lambda}(^1S_0)$ respectively.