相关论文: A method to estimate primary composition with the …
To interpret the mean depth of cosmic ray air shower maximum and its dispersion, we parametrize those two observables as functions of the first two moments of the $\ln A$ distribution. We examine the goodness of this simple method through…
The shape of the longitudinal development of the showers generated in the atmosphere by very high energy cosmic ray particles encodes information about the mass composition of the flux, and about the properties of hadronic interactions that…
The fluorescence technique has been successfully used to detect ultrahigh energy cosmic rays by indirect measurements. The underlying idea is that the number of charged particles in the atmospheric shower, i.e, its longitudinal profile, can…
The Pierre Auger Observatory has conducted measurements of the energy spectrum and mass composition of cosmic rays using different methods. Utilizing both surface and fluorescence detectors (SD and FD), the Observatory provides…
The chemical composition of ultra high energy cosmic rays is still uncertain. The latest results obtained by the Pierre Auger Observatory and the HiRes Collaboration, concerning the measurement of the mean value and the fluctuations of the…
The characteristics of an extensive air shower derive from both the mass of the primary ultra-high-energy cosmic ray that seeds its development and the properties of the hadronic interactions that feed it. With its hybrid detector design,…
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…
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…
The Pierre Auger Observatory is currently the largest observatory of Ultra High Energy Cosmic Rays. Having more data collected than any previous experiment and using a hybrid technique, it can provide important information to unveil the…
Several methods can be used to perform statistical inference of primary composition of cosmic rays measured with water Cerenkov detectors as those in use at the Pierre Auger Southern Observatory. In the present work we assess the impact of…
The Pierre Auger Observatory aims to determine the nature and origin of the ultra-high energy cosmic rays (UHECR). The Auger hybrid detector combines fluorescence observations of extended air showers, initiated in the atmosphere by these…
This paper presents the highlights from the recent measurements of the energy spectrum, mass composition, and arrival directions of the ultra-high energy ($> 10^{17}$ eV = 0.1 EeV) cosmic rays (UHECR) by the Pierre Auger Observatory. The…
We report a study of the distributions of the depth of maximum, Xmax, of extensive air-shower profiles with energies above 10^17.8 eV as observed with the fluorescence telescopes of the Pierre Auger Observatory. The analysis method for…
The Pierre Auger Observatory has been designed to investigate the most energetic particles known, the ultra high energy cosmic rays. The observatory, covering an area of 3000 km^2, combines two different detection techniques to study the…
The interaction of Ultra High Energy Cosmic Rays (UHECRs) with the atoms of the atmosphere can occur at center-of-mass energies that surpass 100 TeV, while present human-made accelerators go up to 13 TeV. Therefore it provides a unique…
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 standard method to estimate the mass of a cosmic ray is the measurement of the atmospheric depth of the shower maximum ($X_\text{max}$). This depth is strongly correlated with the mass of the primary because it depends on the…
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 Pierre Auger Observatory, recently completed, has been operational since 2004. As a hybrid experiment, it allows for a wide range of measurements of UHECR-induced extensive air showers (EAS), including measurements of the EAS particle…
The muon content of extensive air showers is an observable sensitive to the primary composition and to the hadronic interaction properties. The Pierre Auger Observatory uses water-Cherenkov detectors to measure particle densities at the…