Related papers: A new method for the UHECR mass composition studie…
A Monte-Carlo study to reconstruct energy and mass of cosmic rays with energies above 300 TeV using ground based measurements of the electromagnetic part of showers initiated in the atmosphere is presented. The shower properties determined…
We present measurements of the atmospheric depth of the shower maximum $X_\mathrm{max}$, inferred for the first time on an event-by-event level using the Surface Detector of the Pierre Auger Observatory. Using deep learning, we were able to…
The Pierre Auger Observatory has been collecting data in a stable manner since January 2004. We present here a study of the cosmic ray composition using events recorded in hybrid mode during the first years of data taking. These are air…
We describe the measurement of the depth of maximum, Xmax, of the longitudinal development of air showers induced by cosmic rays. Almost four thousand events above 10^18 eV observed by the fluorescence detector of the Pierre Auger…
We show that the maximum shower depth distributions of Ultra-High Energy Cosmic Rays (UHECRs), as measured by fluorescence telescopes, can be augmented by building a mapping to observables collected by surface detectors. The resulting…
Our study exploits the Constant Intensity Cut principles applied simultaneously to muonic and electromagnetic detectors of cosmic rays. We use the fact that the ordering of events according to their signal sizes induced in different types…
Determination of mass composition of high energy cosmic rays is one of the greatest challenge in modern astrophysics. All of previous methods for finding the mass composition of primary cosmic rays in a surface array at least require two…
In this paper we review air shower data related to the mass composition of cosmic rays above 10$^{15}$ eV. After explaining the basic relations between air shower observables and the primary mass and energy of cosmic rays, we present…
The current generation of air shower radio arrays has demonstrated that the atmospheric depth of the shower maximum Xmax can be reconstructed with high accuracy. These experiments are now contributing to mass composition studies in the…
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…
The properties of cosmic rays with energies above 10**6 GeV have to be deduced from the spacetime structure and particle content of the air showers which they initiate. In this review we summarize the phenomenology of these giant air…
Telescope Array (TA) has recently published results of nearly nine years of $X_{\mathrm{max}}$ observations providing its highest statistics measurement of ultra high energy cosmic ray (UHECR) mass composition to date for energies exceeding…
We propose a novel approach for the determination of the nature of ultra-high energy cosmic rays by exploiting the geomagnetic deviation of muons in nearly horizontal showers. The distribution of the muons at ground level is well described…
In this article I review the main theoretical problems that are posed by the highest energy end of the observed cosmic ray spectrum, stressing the importance of establishing their composition in order to decide between proposed scenarios. I…
The Fluorescence Detector of the Pierre Auger Observatory measures the atmospheric depth, $X_{max}$, where the longitudinal profile of the high energy air showers reaches its maximum. This is sensitive to the nuclear mass composition of the…
The determination of the mass composition of the highest energy cosmic rays is one of the greatest challenges in cosmic ray experiments. The highest energy cosmic rays are only detected indirectly because of their very low flux. Using the…
Observations of cosmic rays have been improving at all energies, with higher statistics and reduced systematics. Fundamental questions remain regarding the origins of cosmic rays both within the Galaxy and in extragalactic sources, and new…
We present measurements of the depth of shower maximum, Xmax, for cosmic-ray-induced extensive air showers recorded by the fluorescence detector of the Pierre Auger Observatory over 17 years. The data set covers primary energies from…
The depth of maximum for extensive air showers measured by Fly's Eye and Yakutsk experiments is analysed. The analysis depends on the hadronic interaction model that determine cascade development. The novel feature found in the cascading…
Measurements of cosmic ray particles at energies above E = 5 x 10^{14} eV are performed by large area ground based air shower experiments. Only they provide the collection power required for obtaining sufficient statistics at the low flux…