arXiv subjects

Miguel Alexandre Martins

Publications and source records attributed to Miguel Alexandre Martins.

5 recordsLinked to original sources

arXiv2026

Forward hadron production in proton-air collisions above LHC energies through the fluctuations of extensive air showers

Primary proton-air interactions at ultra-high energies leave a physically interpretable imprint on the correlated fluctuations of the depth of shower maximum and the muon content in extensive air showers. This imprint reflects the stochasticity in the partition of the primary energy among secondary particles in the first interaction. We show that these fluctuations can be accessed through a probabilistic description that isolates sensitivity to hadronic physics in the initial collision, while treating the subsequent shower development as effectively universal. The uncertainties resulting from this universality are smaller than the spread among current hadronic interaction models and comparable to current experimental uncertainties. Consequently, the joint observable space defined by these two quantities provides a new probe of hadron production in kinematic regimes far beyond the reach of human-made accelerators.

astro-ph.HE↗

arXiv2025

Probabilistic mapping between multiparticle production variables and the depth of maximum in proton-induced extensive air showers

The interaction of ultra-high-energy cosmic rays with air nuclei triggers extensive air showers that reach their maximal energy deposition at the atmospheric depth $X_{\max}$. The distribution of this shower observable encodes information about the proton-air cross-section via fluctuations of the primary interaction point, $X_1$, and hadron production through $ΔX_{\max} \equiv X_{\max} - X_1$. We introduce new multiparticle production variables, $α_{\textrm{had}}$, $ζ_{\textrm{had}}$, and $ζ_{\mathrm{EM}}$, built from the energy spectra of secondaries in the primary interaction. Their linear combination, $ξ$, predicts over $50 \%$ of the fluctuations in $ΔX_{\max}$. Moreover, we build a probabilistic mapping based on the causal connection between $ξ$ and $ΔX_{\max}$ that enables model-independent predictions of $X_{\max}$ moments with biases below $3\,\mathrm{g\,cm^{-2}}$. Therefore, measurements of the distribution of $X_{\max}$ allow a data-driven probing of secondary hadron spectra from the cosmic-ray-air interaction, in proton-induced showers. The distributions of the new multiparticle production variables can be measured in rapidity regions accessible to current accelerators and are strongly dependent on the hadronic interaction model in the kinematic regions exclusive to ultra-high-energy cosmic rays.

astro-ph.HE↗

arXiv2024

Proton-air interactions at ultra-high energies in muon-depleted air showers with different depths

The hardness of the energy spectrum of neutral pions produced in proton-air interactions at ultra-high energies, above $10^{18}$ eV, is constrained by the steepness of the shower-to-shower distribution of the number of muons in muon-depleted extensive air showers. In this work, we find that this steepness, quantified by the parameter $Λ_μ$, evolves with the depth of the shower maximum, $X_{\max}$, assuming a universal value for shallow showers and an enhanced dependence on the high-energy hadronic interaction model for deep showers. We show that Xmax probes the so-called hadronic activity of the first interaction, thus allowing direct access to the energy spectrum of neutral pions in different regions of the kinematic phase space of the first interaction. We verify that the unbiased measurement of $Λ_μ$ is possible for realistic mass composition expectations. Finally, we infer that the statistical precision in $Λ_μ$ required to distinguish between hadronic interaction models can be achieved in current extensive air shower detectors, given their resolution and exposure.

astro-ph.HE↗

arXiv2021

Constraining the energy spectrum of neutral pions in ultra-high-energy proton-air interactions

Fluctuations in the muon content of extensive air showers are anticorrelated to the fluctuations of the energy taken by the neutral pions which emerge from the first interaction of the cosmic ray in the atmosphere. We show that the high-energy tail of the neutral pion spectrum produced in the first proton-air interaction can be constrained, within the uncertainties of present cosmic ray experiments, through the analysis of the shower-to-shower distribution of the muon content of the air showers, $P(N_μ)$.

astro-ph.HE↗

arXiv2018

Probing the $π^0$ spectrum at high-$x$ in proton-Air interactions at ultra-high energies

The average number of muons in air showers and its connection with shower development has been studied extensively in the past. With the upcoming detector upgrades, UHECR observatories will be able to probe higher moments of the distribution of the number of muons. Here a study of the physics of the fluctuations of the muon content is presented. In addition to proving that the fluctuations must be dominated by the first interactions, we show that low-$N_μ$ tail of the shower-to-shower distribution of the number of muons is determined by the high-$x_{\rm L}$ region of the production cross-section of neutral pions in the first interaction.

astro-ph.HE↗