Production of $K^{-}pp$ and $K^{+}\overline{p}\overline{p}$ in $pp$ collisions at $\sqrt{s}=7$ TeV

The production of charged particles $K^{\pm },p$, and $\overline{p}$ is simulated using the paciae model at scaled midrapidity $\left|y\right|<0.5$ in proton-proton collisions at $\sqrt{s}=7$ TeV. The simulation results are consistent with ALICE experimental data on $K^{\pm },p$, and $\overline{p}$ yield, with the transverse momentum of kaon at 0.2–6 GeV/$c$ and proton at 0.3–6 GeV/$c$. Furthermore, the production of $K^{-}pp$ and $K^{+}\overline{p}\overline{p}$ is predicted in the dynamically constrained phase-space coalescence (dcpc) model, based on the hadronic final states produced in the paciae model. It is found that the yield of $K^{-}pp$ is around $5\times {10}^{-4}$, much larger than the yield of the $K^{+}\overline{p}\overline{p}$ following the hypothesis that $K^{-}pp$ and $K^{+}\overline{p}\overline{p}$ are formed in the way that a $K^{-}\left(K^{+}\right)$ traps two protons (antiprotons) directly, without going through the so-called ${\mathrm{\Lambda }}^{*}p$ doorway state.

Figure 1

Molecular structure of kaonic nucleus $K^{-}pp$ [4].

Figure 2

Yield per event of $K^{-}pp$ (upper) and $K^{+}\overline{p}\overline{p}$ (lower) as a function of the event number with $\mathrm{\Delta }m=0.03$ GeV in pp collisions at $\sqrt{s}=7\mathrm{TeV}$.

Figure 3

Yield per event of $K^{-}pp$ as a function of $\mathrm{\Delta }m$ ranging from 0.02 to 0.05 GeV in $pp$ collisions at $\sqrt{s}=7$ TeV. Results are taken from Table 2.

Figure 4

Yield per event of $K^{+}\overline{p}\overline{p}$ as a function of $\mathrm{\Delta }m$ ranging from 0.02 to 0.05 GeV in $pp$ collisions at $\sqrt{s}=7$ TeV. Results are taken from Table 2.