Improved simulation of extensive air showers with a medium-strong interaction

An improved version of a previous simulation of extensive air showers above 10¹³ eV is discussed. In the simulation, the central assumption of a medium-strong contact interaction between protons is retained, but a model is used in which secondary pions are produced during pp collisions rather than through isobar decay. The influence of several different expressions for the multiplicity of pions and for the magnetic form factor of the proton is examined. While these expressions have noticeable quantitative effects on the behavior of the showers, the previous qualitative observation that the medium-strong interaction leads to a gradual increase in a measure of transverse momentum above a primary energy of 10¹⁴ eV is unchanged.