Related papers: Extracting a less model dependent cosmic ray compo…
Sokolsky and D_Avignon have recently reported an examination of a variety of measurements that relate to the question as to how the mass composition of the highest-energy cosmic-rays evolves with energy. They assert that cosmic rays…
The Pierre Auger Observatory has driven the field of ultra-high-energy cosmic ray (UHECR) physics, producing several groundbreaking observations over the last 20 years. One of the most striking findings has been the complex evolution of…
The lateral distribution of muons with ~1.0x\sec(\theta) GeV in extensive air showers within ~10^{17}-10^{19} eV energy region obtained during different observational periods from November 1987 to June 2013 has been analyzed. Experimental…
The origin and chemical composition of ultra high energy cosmic rays is still an open question in astroparticle physics. The observed large-scale isotropy and also direct composition measurements can be interpreted as an extragalactic…
The combination of fluorescence and surface detectors at the Pierre Auger Observatory offers unprecedented precision in testing models of hadronic interactions at center-of-mass energies around 70 TeV and beyond. However, for some time,…
The percent-level precision attained by modern cosmic ray (CR) observations motivates reaching a comparable or better control of theoretical uncertainties. Here we focus on energy-loss processes affecting low-energy CR protons ($\sim 0.1-5$…
Recent cosmic-ray (CR) studies have claimed the possibility of an excess on the antiproton flux over the predicted models at around $10$ GeV, which can be the signature of dark matter annihilating into hadronic final states that…
We report a first measurement for ultra-high energy cosmic rays of the correlation between the depth of shower maximum and the signal in the water Cherenkov stations of air-showers registered simultaneously by the fluorescence and the…
Elements of nuclear symmetry energy evaluated from different energy density functionals parametrized by fitting selective bulk properties of few representative nuclei are seen to vary widely. Those obtained from experimental data on nuclear…
The origin of ultra high energy cosmic rays (UHECR) is still unknown. However, great progress has been achieved in past years due to the good quality and large statistics in experimental data collected by the current observatories. The data…
The precise spectra of Cosmic Ray (CR) electrons and positrons have been published by the measurement of AMS-02. It is reasonable to regard the difference between the electrons and positrons spectra ( $\triangle \Phi= \Phi_{e^-}-\Phi_{e^+}$…
We explore particle physics beyond accelerator energies, motivated by questions exposed in astroparticle physics observations: 1) Are there reasonable modifications to the standard extrapolations of LHC-tuned hadronic interaction models, so…
Resonant photopion production with the cosmic microwave background predicts a suppression of extragalactic protons above the famous Greisen-Zatsepin-Kuzmin cutoff at about E_{GZK} ~ 5 x 10^10 GeV. Current cosmic ray data measured by the…
We study basic characteristics of distributions of the depths of shower maximum in air showers caused by cosmic rays with the highest energies. The consistency between their average values and widths, and their energy dependences are…
Mass composition is important for understanding the origin of ultra-high-energy cosmic rays. However, interpretation of mass composition from air shower experiments is challenging, owing to significant uncertainty in hadronic interaction…
The determination of the primary energy and mass of ultra-high-energy cosmic-rays (UHECR) generating extensive air-showers in the Earth's atmosphere, relies on the detailed modeling of hadronic multiparticle production at center-of-mass…
So far the only seemingly significant indication of a cosmological variation exists for the proton-to-electron mass ratio as stated by Reinhold et al. (2006). The measured indication of variation is based on the combined analysis of H2…
The unprecedented quality of the data collected by the AMS-02 experiment onboard the International Space Station allowed us to address subtle questions concerning the origin and propagation of cosmic rays. Here we discuss the implications…
The Pierre Auger Observatory's (PAO) shower profile measurements can be used to constrain the chemical composition of the ultra-high energy cosmic ray (UHECR) spectrum. In particular, the PAO's measurements of the average depth of shower…
We present an analysis of the correlation between the depth of the maximum of air-shower profiles and the signal in water-Cherenkov stations in events registered simultaneously by the fluorescence and surface detectors of the Pierre Auger…