Particle production in $p\text{−}p$ collisions and predictions for $\sqrt{s}=14$ TeV at the CERN Large Hadron Collider (LHC)

We analyze recent data on particle production yields obtained in $p\text{−}p$ collisions at SPS and RHIC energies within the statistical model. We apply the model formulated in the canonical ensemble and focus on strange particle production. We introduce different methods to account for strangeness suppression effects and discuss their phenomenological verification. We show that at RHIC the midrapidity data on strange and multistrange particle multiplicity can be successfully described by the canonical statistical model with and without an extra suppression effects. On the other hand, SPS data integrated over the full phase-space require an additional strangeness suppression factor that is beyond the conventional canonical model. This factor is quantified by the strangeness saturation parameter or strangeness correlation volume. Extrapolating all relevant thermal parameters from SPS and RHIC to LHC energy we present predictions of the statistical model for particle yields in $p\text{−}p$ collisions at $\sqrt{s}=14$ TeV. We discuss the role and the influence of a strangeness correlation volume on particle production in $p\text{−}p$ collisions at LHC.

Figure 1

Particle ratios as a function of the volume radius $R$. The temperature $T=170$ MeV and the baryon chemical potential ${\mu }_B=1$ MeV were chosen according to the thermal conditions expected to be valid at LHC energy. All ratios are normalized to their grand canonical values.

Figure 2

Integrated particle yields from $p\text{−}p$ collisions at $\sqrt{s}=17.3$ GeV [25, 26, 27, 28] together with different model predictions: (a), (b), and (c) introduced in the text. The lower panel shows the deviation of the model fits to data.

Figure 3

Midrapidity particle densities from $p\text{−}p$ collisions at $\sqrt{s}=200$ GeV from STAR [29, 30] together with the model fits as in Fig. 2. The lower panel shows the ${\chi }^2$-deviations of the model fits to data.

Figure 4

Cluster radius $R_C$ as a function of energy, extracted from the present analysis of SPS data (triangle) and RHIC data (star). Also shown is the previous analysis [13] of a smaller set of SPS data (square). The lines illustrate possible evolutions toward LHC energies as discussed in the text.

Figure 5

Predictions for various particle ratios using different values for $R_C$.

Figure 6

Particle ratio $\Omega /\pi$ as a function of $R_C$ for two assumed temperatures, $T=160$ MeV (dashed) and $T=170$ MeV (full line).