How uncertain are model predictions for the muon content of extensive air showers

Abstract

The relation of model predictions for muon content of extensive air showers (EAS) to particular properties of hadron-air interactions is discussed. Further, using a new Monte Carlo generator of cosmic ray interactions, QGSb, the relevance of particular interaction mechanisms to the predicted EAS muon number is studied in some detail. The corresponding constraints imposed by accelerator measurements are discussed as well.

Figures (10)

• Figure 1: Schematic view of the contribution of pion exchange process to forward production of $\rho$ mesons in pion-proton (pion-nucleus) interactions. At a microscopic level, the process is mediated by a creation of light quark-antiquark pairs from the vacuum ($\bar{d}d$ in the figure).
• Figure 2: Feynman $x$ distributions, $dn/dx_{\rm F}$, of $\rho^0$ mesons in center-of-mass (c.m.) frame, for $\pi^-C$ collisions at 158 GeV/c (left) and 350 GeV/c (right), as calculated using the default QGSb or by considering a higher rate of pion exchange process -- red solid and blue dashed lines, respectively, compared to NA61/SHINE data (points).
• Figure 3: $x_{\rm F}$-dependence of production cross sections in c.m. frame for $\rho^0$ (left) and $\rho^+$ (right), for $\pi^+p$ collisions at 250 GeV/c, compared to EHS-NA22 data (points). The notations for the lines are the same as in Fig. \ref{['fig:na61-rho']}.
• Figure 4: Schematic view of the contribution of the fragmentation of valence (anti)quarks, proceeding via a creation of $\bar{s}s$ pairs from the vacuum, to forward production of kaons in pion-proton (pion-nucleus) interactions.
• Figure 5: Laboratory (lab.) momentum distributions of $K^{+}$ (left panels), $K^{-}$ (middle panels), and $K_{\rm S}^0$ (right panels) produced in $\pi^-$C collisions at 158 GeV/c (top row) and 350 GeV/c (bottom row), compared to NA61/SHINE data (points). The calculations performed using the default QGSb or by considering a higher probability for $\bar{s}s$ pair creation from the vacuum are shown, respectively, by red solid and blue dashed lines.