Model-Stable Universality of the Air Shower Electromagnetic Component:   an Approach to Solving the Mass Composition Problem
  On the basis of the scaling approach and CORSIKA simulations data the radial scale factor of lateral distribution of electrons in extensive air showers is confirmed as potentially effective primary mass estimator, and its sensitivity to hadronic interaction model is investigated. It is shown that improved composition results both on average and event-by-event basis can be achieved taking into account the universality property of air shower development expressed by the relation between radial scale factor and longitudinal age parameter. The enhancements of such a theoretically motivated tool for the unbiased cosmic ray composition deduction in a wide primary energy range from (multi-)hybrid air shower measurements of nearest future are discussed. 
R. Raikin, T. Serebryakova, A. Lagutin, N. Volkov
astro-ph.HE hep-ph