Probing the energy spectrum of hadrons in proton air interactions at ultrahigh energies through the fluctuations of the muon content of extensive air showers

Abstract

We demonstrate that the shower-to-shower fluctuations of the muon content of extensive air showers correlate with the fluctuations of a variable of the first interaction of Ultra High Energy Cosmic Rays, which is computed from the fraction of energy carried by the hadrons that sustain the hadronic cascade. The influence of subsequent stages of the shower development is found to play a sub-dominant role. As a consequence, the shower-to-shower distribution of the muon content is a direct probe of the hadron energy spectrum of interactions beyond those reachable in human-made accelerators.Keywords: high energy hadron interactions; ultrahigh energy cosmic rays; extensive air showers; muon production; fluctuations; hadron energy spectrum; arXiv:/hep-ph/1803.05699 The shower-to-shower fluctuations in the muon content of proton-induced EASEAS initiated by UHECRs develop in two components: the hadronic and the electromagnetic (EM) cascades. The EM component consists of photons, electrons and positrons. It arises from the EM decay of mesons in the hadronic component, predominantly from neutral pions, π 0 . Photons and electrons in the EM cascade only rarely undergo interactions that produce hadrons. In each interaction, approximately a third of the energy is transferred from the hadronic to the EM cascade, cor-

Probing High-Energy Hadronic Interactions with Extensive Air Showers

“…, which clearly decreases as the generation number gets higher. As a result the relative fluctuations of N µ are dominated by the fluctuations of α 1 in the 1st inter-action [52]. In p-Air interactions ∼ 70% of the variance is due to the first interaction, whereas for nuclei of mass A, the fluctuations are reduced by a factor ∼ 1/ √ A.…”

“…The continuous and smooth deviation of simulations with respect to data from low energies seen in Figure 9 supports the hypothesis of a small cumulative, generation after generation, effect rather than a sudden change. In [52], a variable of the 1st interaction that combines the multiplicity and energy taken by the particles feeding the hadronic cascade was defined as…”

Probing the π0 spectrum at high-x in proton-Air interactions at ultra-high energies

“…3 in the range where E had /E 0 = 0.8-1), the correlation between the number of muons and E had is small. Taking the multiplicity of hadrons that are produced in the first interaction into account, this region can be described as well and the correlation can be increased further [10]. Comparing the size of the fluctuations, we find that the variance of the hadronic energy and multiplicity in the first interaction accounts for 80% of the total variance 3 .…”

“…In order to get a clean measurement of the tail of the distribution the composition in the tail ought to be pure proton. For heavier primaries, the tail of the distribution of N µ is suppressed further and further with increasing number of nucleons the primary cosmic ray [10]. Hence the conditions for a measurement are best for proton primaries.…”

Modelo estatístico para desenvolvimento de chuveiros atmosféricos extensos

“…Por isso há importância em saber aspectos básicos de cada um e suas implicações no resultado referente à produção da partículas em colisões entre um projétil e um alvo fixo. Para um leitor que queira mais detalhes sobre os cálculos teóricos e eventuais procedimentos computacionais, pode-se encontra-los nas referências (28,37,(39)(40)(41). † Cerca de 430 TeV, no centro de massa.…”