Production of $K^{-}p$ and $K^{+}\overline{p}$ bound states in $pp$ collisions and interpretation of the $\mathrm{\Lambda }\left(1405\right)$ resonance

We study the production of charged particles ($K^{+}$, $K^{-}$, $p$, and $\overline{p}$) in proton-proton ($pp$) collisions at $\sqrt{s}=0.9\mathrm{TeV}$ 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 $K^{-}p$ and $K^{+}\overline{p}$ bound states with the paciae+dcpc model. Results of our work indicate that in $pp$ collisions at $\sqrt{s}=0.9\mathrm{TeV}$ the $\mathrm{\Lambda }\left(1405\right)$ and its antiparticle may be produced at almost the same rate if the $\mathrm{\Lambda }\left(1405\right)$ is a $K^{-}p$ bound state formed during the hadron rescattering period. The combined yield of $K^{-}p$ and $K^{+}\overline{p}$ bound states is found to be of the order of ${10}^{-3}$, but the experimental results indicate that the combined yield of $\mathrm{\Lambda }\left(1405\right)+\overline{\mathrm{\Lambda }}\left(1405\right)$ is of the order of ${10}^{-2}$ if $\mathrm{\Lambda }\left(1405\right)$ 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.

Figure 1

The rms distance between $K^{-}$ and $p$ [42].

Figure 2

The average yield per event of $K^{-}p$ (a) and $K^{+}\overline{p}$ (b) as a function of the number of events in $pp$ collisions at $\sqrt{s}=0.9\mathrm{TeV}$.

Figure 3

Yields per event of $K^{-}p$ and $K^{+}\overline{p}$. Results taken from Table 3.