Production of K−p and K+p¯ bound states in pp collisions and interpretation of the Λ(1405) resonance

Abstract

We study the production of charged particles (${K}^{+}$, ${K}^{\ensuremath{-}}$, $p$, and $\overline{p}$) in proton-proton ($pp$) collisions at $\sqrt{s}=0.9\phantom{\rule{4pt}{0ex}}\mathrm{TeV}$ within the paciae model whose parameters we fix by comparing the yield of charged particles with experimental data from ALICE. We analyze the production of ${K}^{\ensuremath{-}}p$ and ${K}^{+}\overline{p}$ bound states with the paciae+dcpc model. Results of our work indicate that in $pp$ collisions at $\sqrt{s}=0.9\phantom{\rule{4pt}{0ex}}\mathrm{TeV}$ the $\mathrm{\ensuremath{\Lambda}}(1405)$ and its antiparticle may be produced at almost the same rate if the $\mathrm{\ensuremath{\Lambda}}(1405)$ is a ${K}^{\ensuremath{-}}p$ bound state formed during the hadron rescattering period. The combined yield of ${K}^{\ensuremath{-}}p$ and ${K}^{+}\overline{p}$ bound states is found to be of the order of ${10}^{\ensuremath{-}3}$, but the experimental results indicate that the combined yield of $\mathrm{\ensuremath{\Lambda}}(1405)+\overline{\mathrm{\ensuremath{\Lambda}}}(1405)$ is of the order of ${10}^{\ensuremath{-}2}$ if $\mathrm{\ensuremath{\Lambda}}(1405)$ is a standard three-quark baryon. Since there are no experimental data available on this observable at present, our work may provide a guide for future experiments.