Test of the hyperon-nucleon interaction within leading order covariant chiral effective field theory

Abstract

Motivated by the recent experimental measurements of differential cross sections of the ${\mathrm{\ensuremath{\Sigma}}}^{\ensuremath{-}}p$ elastic scattering in the momentum range of 470 to $850\phantom{\rule{4pt}{0ex}}\mathrm{MeV}/c$ by the J-PARC $\mathrm{E}40$ experiment, we extend our previous studies of $S=\ensuremath{-}1$ hyperon-nucleon interactions to relatively higher energies up to $900\phantom{\rule{4pt}{0ex}}\mathrm{MeV}/c$ for both the coupled-channel $\mathrm{\ensuremath{\Lambda}}p\ensuremath{\rightarrow}(\mathrm{\ensuremath{\Lambda}}p,{\mathrm{\ensuremath{\Sigma}}}^{+}n,{\mathrm{\ensuremath{\Sigma}}}^{0}p)$, ${\mathrm{\ensuremath{\Sigma}}}^{\ensuremath{-}}p\ensuremath{\rightarrow}(\mathrm{\ensuremath{\Lambda}}n,{\mathrm{\ensuremath{\Sigma}}}^{0}n,{\mathrm{\ensuremath{\Sigma}}}^{\ensuremath{-}}p)$ and single-channel ${\mathrm{\ensuremath{\Sigma}}}^{+}p\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Sigma}}}^{+}p$ reactions. We show that although the leading order covariant chiral effective field theory is only constrained by the low energy data, it can describe the high energy data reasonably well, in particular, the J-PARC E40 differential cross sections. The predicted cusp structure close to the $\mathrm{\ensuremath{\Sigma}}N$ threshold in the $\mathrm{\ensuremath{\Lambda}}p\ensuremath{\rightarrow}\mathrm{\ensuremath{\Lambda}}p$ reaction agrees with the latest ALICE observation as well as with the results of the next-to-leading order heavy baryon chiral effective theory. On the other hand, the comparison with the latest CLAS data on the $\mathrm{\ensuremath{\Lambda}}p$ cross sections between 0.9 and 2.0 $\mathrm{GeV}/c$ clearly indicates the need for higher order chiral potentials for such high momenta. This is also the case for the latest J-PARC data on the $\mathrm{\ensuremath{\Sigma}}p\ensuremath{\rightarrow}\mathrm{\ensuremath{\Lambda}}n$ differential cross sections. Nevertheless, even for these cases, the predictions are in qualitative agreement with the data, albeit with large uncertainties, implying that the predicted total and differential cross sections are of relevance for ongoing and planned experiments.