Time characteristics of electron, muon, and Cherenkov photon fronts in giant air showers - art. no. 033004

Calculations of the space-time structure of giant air showers in the energy range 10(17)-10(21) eV carried out in the framework of the quark-gluon str ing model show the existence of three separate disks (or better lenses) of muons, Cherenkov photons, and electrons which follow each other. In a showe r with an energy of 10(19) eV time delays at 1000 m from the shower core ca n be as large as 420, 450, and 1120 ns for muons, Cherenkov photons, and el ectrons, respectively, while the disk thickness for these three components can reach the values of 500, 680, and 1160 ns, respectively. At larger core distances the time delay and disk thickness may exceed a few mu s and shou ld be taken into account both in designing the new array electronics and in terpreting the experimental data. Highly inclined showers which consist mai nly of muons display a much flatter front: time delay decreases down to abo ut 110 ns at a distance of 1000 m from the shower core. Approximations of t he time parameters dependence on the primary energy and core distance are p resented. The measurements of electron, muon, and Cherenkov photon time pul ses are suggested to improve the estimations of the arrival direction and t he energy of the showers and also to study the primary particle composition and parameters of hadron interactions at energies above 10(19) eV. [S0556- 2821(99)06411-5].