Particle production in very-high-energy cosmic-ray emulsion chamber events: Usual and unusual events

Abstract

We show that a simple scaling model of very forward particle production, consistent with accelerator and air shower data, can describe all features of the very high-energy interactions recorded with emulsion chambers. This is somewhat surprising after numerous claims that the same data implied large scaling violations or new dynamics. Interestingly, we cannot describe some of the Centauro events, suggesting that these events are anomalous independently of their well-advertised unusual features such as the absence of neutral secondaries.

Composition of primary cosmic rays beyond the "knee" from emulsion chamber observations

“…We conclude that with the simplest assumptions for the production of secondaries based on approximate scaling in the fragmentation region, it is possible to explain a broad set of experimental data on very high energy cosmic rays in the atmosphere, namely the lateral spread and the integral spectra of superfamilies (as in Ref. [3] and Fig. 1), and the energy spectra of hadronic and electromagnetic showers detected in large emulsion chamber experiments (as in Figs.…”

“…Ursa Maior event (♦) and Centauro VII data (△), are compared to the calculation of Ref. [3] (solid line), using the x-distribution of Eq. ( 1).…”

“…We nevertheless pursue this challenge because we are confident that we understand particle interactions with sufficient accuracy to meaningfully approach this problem. We have indeed formulated a model which is based on the most straightforward assumptions and which respects the spirit of quantum chromodynamics [3]. More importantly, it describes in quantitative detail single events, i.e.…”

“…Our model of particle production [3] is guided by the features of QCD-inspired models: approximate Feynman scaling in the fragmentation region and an inelasticity slowly varying with energy. The rapidity density of secondary charged pions is parametrized as…”

High energy neutrinos from charm in astrophysical sources

“…For π ± and K ± production, however, we assume Feynman scaling, leading to energy independent Z-moments. To compute the Z-moments for pp we use the parametrization of the rapidity distribution [28]…”