Indications of Proton-Dominated Cosmic Ray Composition above 1.6 EeV

Abstract

We report studies of ultra-high energy cosmic ray composition via analysis of depth of airshower maximum (Xmax), for airshower events collected by the High Resolution Fly's Eye (HiRes) observatory. The HiRes data are consistent with a constant elongation rate d<Xmax>/d(log(E)) of 47.9 +- 6.0 (stat.) +- 3.2 (syst.)g/cm^2/decade for energies between 1.6 EeV and 63 EeV, and are consistent with a predominantly protonic composition of cosmic rays when interpreted via the QGSJET01 and QGSJET-II high-energy hadronic interaction models. These measurements constrain models in which the galactic-to-extragalactic transition is the cause of the energy spectrum "ankle' at 4 EeV.

11 pages, 4 figures, accepted for publication in Physical Review Letters

References in corpus (2)

• Measurement of the Depth of Maximum of Extensive Air Showers above 10^18 eV
• Measurement of the Flux of Ultra High Energy Cosmic Rays by the Stereo Technique

Cited by in corpus (140)

• Cosmological Magnetic Fields: Their Generation, Evolution and Observation
• The Astrophysics of Ultrahigh Energy Cosmic Rays
• Measurements of the Cosmic Ray Composition with Air Shower Experiments
• Depth of Maximum of Air-Shower Profiles at the Pierre Auger Observatory: Measurements at Energies above 10^17.8 eV
• The Giant Radio Array for Neutrino Detection (GRAND): Science and Design
• The microphysics of collisionless shock waves
• Cosmogenic Neutrinos: parameter space and detectabilty from PeV to ZeV
• Blazars as Ultra-High-Energy Cosmic-Ray Sources: Implications for TeV Gamma-Ray Observations
• Study of Ultra-High Energy Cosmic Ray Composition Using Telescope Array's Middle Drum Detector and Surface Array in Hybrid Mode
• Constraints from the first LHC data on hadronic event generators for ultra-high energy cosmic-ray physics
• Ultrahigh Energy Cosmic Rays
• Depth of Ultra High Energy Cosmic Ray Induced Air Shower Maxima Measured by the Telescope Array Black Rock and Long Ridge FADC Fluorescence Detectors and Surface Array in Hybrid Mode
• Ultra High Energy Cosmic Rays: The disappointing model
• Supermassive black holes as possible sources of ultra high energy cosmic rays
• GRBs on probation: testing the UHE CR paradigm with IceCube
• Constraints on the origin of cosmic rays above $10^{18}$ eV from large scale anisotropy searches in data of the Pierre Auger Observatory
• CRPropa 2.0 -- a Public Framework for Propagating High Energy Nuclei, Secondary Gamma Rays and Neutrinos
• Gamma-Ray Burst Science in the Era of the Cherenkov Telescope Array
• Interpretation of the Depths of Maximum of Extensive Air Showers Measured by the Pierre Auger Observatory
• The origin of cosmic rays: Explosions of massive stars with magnetic winds and their supernova mechanism
• Anisotropies of ultra-high energy cosmic rays diffusing from extragalactic sources
• The need for a local source of UHE CR nuclei
• Neutrino Background Flux from Sources of Ultrahigh-Energy Cosmic-Ray Nuclei
• Ultrahigh-energy Cosmic-ray Nuclei from Black Hole Jets: Recycling Galactic Cosmic Rays through Shear Acceleration
• Search for Anisotropy of Ultra-High Energy Cosmic Rays with the Telescope Array Experiment
• Ultrahigh Energy Cosmic Ray Nuclei from Extragalactic Pulsars and the effect of their Galactic counterparts
• Role of Galactic sources and magnetic fields in forming the observed energy-dependent composition of ultrahigh-energy cosmic rays
• Ultra High Energy Cosmic Ray Acceleration in Engine-driven Relativistic Supernovae
• Gamma-Ray Constraints on Maximum Cosmogenic Neutrino Fluxes and UHECR Source Evolution Models
• SimProp: a Simulation Code for Ultra High Energy Cosmic Ray Propagation
• Bounds on the density of sources of ultra-high energy cosmic rays from the Pierre Auger Observatory
• Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum and composition
• Introduction to the physics of the total cross-section at LHC: A Review of Data and Models
• Mass composition of ultra-high-energy cosmic rays with the Telescope Array Surface Detector Data
• Fifty years of energy extraction from rotating black hole: revisiting magnetic Penrose process
• Heavy Nuclei Synthesized in Gamma-Ray Burst Outflows as the Source of UHECRs
• Large scale distribution of arrival directions of cosmic rays detected above $10^{18}$ eV at the Pierre Auger Observatory
• Measurement of forward neutral pion transverse momentum spectra for $\sqrt{s}$ = 7TeV proton-proton collisions at LHC
• Cosmogenic gamma-rays and the composition of cosmic rays
• Analysis of large-scale anisotropy of ultra-high energy cosmic rays in HiRes data
• Cosmic rays in galactic and extragalactic magnetic fields
• Ultra-High Energy Cosmic Rays from Centaurus A: Jet Interaction with Gaseous Shells
• Constraints on the flux of primary cosmic-ray photons at energies E > 10^18 eV from Yakutsk muon data
• High-Energy Emission Induced by Ultra-High-Energy Photons as a Probe of Ultra-High-Energy Cosmic-Ray Accelerators Embedded in the Cosmic Web
• High-Energy Cosmic Rays and the Greisen-Zatsepin-Kuzmin Effect
• Spacetime noncommutativity and ultra-high energy cosmic ray experiments
• Final Results from the High Resolution Fly's Eye (HiRes) Experiment
• Cosmic PeV Neutrinos and the Sources of Ultrahigh Energy Protons
• Very-High-Energy Gamma-Ray Signal from Nuclear Photodisintegration as a Probe of Extragalactic Sources of Ultrahigh-Energy Nuclei
• Reinterpreting the development of extensive air showers initiated by nuclei and photons
• Measurement of the cosmic ray energy spectrum using hybrid events of the Pierre Auger Observatory
• Detection of ultra-high energy cosmic ray showers with a single-pixel fluorescence telescope
• Production and propagation of ultra-high energy photons using CRPropa 3
• Measurement of zero degree inclusive photon energy spectra for $\sqrt{s}=$ 900 GeV proton-proton collisions at LHC
• Search for EeV Protons of Galactic Origin
• Layered water Cherenkov detector for the study of ultra high energy cosmic rays
• Baryon Loading Efficiency and Particle Acceleration Efficiency of Relativistic Jets: Cases For Low Luminosity BL Lacs
• Multi-PeV Signals from a New Astrophysical Neutrino Flux Beyond the Glashow Resonance
• Diffusion of cosmic rays at EeV energies in inhomogeneous extragalactic magnetic fields
• A targeted search for point sources of EeV photons with the Pierre Auger Observatory
• The Role of Structured Magnetic Fields on Constraining Properties of Transient Sources of Ultra-high-energy Cosmic Rays
• Strangelets and the TeV-PeV cosmic-ray anisotropies
• Propagation of extragalactic photons at ultra-high energy with the EleCa code
• Mass composition of cosmic rays above 0.1 EeV by the Yakutsk array data
• Constraining the Emissivity of Ultrahigh Energy Cosmic Rays in the Distant Universe with the Diffuse Gamma-ray Emission
• The Centaurus A Ultrahigh-Energy Cosmic Ray Excess and the Local Extragalactic Magnetic Field
• Neutron β-decay as the origin of IceCube's PeV (anti)neutrinos
• On ultra high energy cosmic rays and their resultant gamma rays
• A Targeted Search for Point Sources of EeV Neutrons
• Describing the Observed Cosmic Neutrinos by Interactions of Nuclei with Matter
• Cosmic Ray in the Northern Hemisphere: Results from the Telescope Array Experiment
• The CALOCUBE project for a space based cosmic ray experiment: design, construction, and first performance of a high granularity calorimeter prototype
• Telescope Array Radar (TARA) Observatory for Ultra-High Energy Cosmic Rays
• Propagation of Ultra-High-Energy Cosmic Ray Nuclei in Cosmic Magnetic Fields and Implications for Anisotropy Measurements
• Interactions between Ultra-High-Energy Particles and Protogalactic Environments
• Sensitivity of the correlation between the depth of shower maximum and the muon shower size to the cosmic ray composition
• Calculations of electric fields for radio detection of Ultra-High Energy particles
• Analytic Solutions of Ultra-High Energy Cosmic Ray Nuclei Revisited
• Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory
• Update on tests of the Cen A neutron-emission model of highest energy cosmic rays
• Detectability of ultrahigh energy cosmic ray signatures in gamma rays
• Muon production and string percolation effects in cosmic rays at the highest energies
• On the model-dependence of the relation between minimum-bias and inelastic proton-proton cross sections
• Cosmic Rays around $10^{18}$eV: Implications of Contemporary Measurements on the Origin of the Ankle Feature
• High energy cosmic-ray interactions with particles from the Sun
• Acceleration and propagation of ultrahigh energy cosmic rays
• On the chemical composition of cosmic rays of highest energy
• A scenario for the Galactic cosmic rays between the knee and the second-knee
• On the excess of ultra-high energy cosmic rays in the direction of Centaurus A
• Mass composition of cosmic rays with energy above 10**17 eV according to surface detectors of the Yakutsk EAS array
• Precise determination of muon and electromagnetic shower contents from shower universality property
• Constraining Sources of Ultra High Energy Cosmic Rays Using High Energy Observations with the Fermi Satellite
• Anisotropy in Cosmic rays from internal transitions in neutron stars
• Hadronic Interactions of Energetic Charged Particles in Protogalactic Outflow Environments and Implications for the Early Evolution of Galaxies
• A signature of EeV protons of Galactic origin
• Neutrinos and cosmic rays
• Feynman scaling violation on baryon spectra in pp collisions at LHC and cosmic ray energies
• IceCube expectations for two high-energy neutrino production models at active galactic nuclei
• A template method for measuring the iron spectrum in cosmic rays with Cherenkov telescopes
• Cosmic ray backgrounds for dark matter indirect detection
• Using spherical wavelets to search for magnetically-induced alignment in the arrival directions of ultra-high energy cosmic rays
• The non-linearity between <ln A> and <Xmax> induced by the acceptance of fluorescence telescopes
• Systematic Survey of the Correlation between Northern HECR Events and SDSS Galaxies
• Cosmic Rays at the highest energies
• Summary of Lepton Photon 2011
• A gamma-ray signature of energetic sources of cosmic-ray nuclei
• Measurements of Cosmic Rays with IceTop/IceCube: Status and Results
• Ultrahigh Energy Cosmic Rays and Neutrinos
• Deep learning method for identifying mass composition of ultra-high-energy cosmic rays
• The Knee and the Second Knee of the Cosmic-Ray Energy Spectrum
• Cosmic Clues from Amaterasu: Blazar-Driven Ultrahigh-Energy Cosmic Rays?
• Nuclear Composition of Magnetized GRB Jets
• Exploiting the geomagnetic distortion of the inclined atmospheric showers
• Abnormal threshold behaviors of photo-pion production off the proton in the GZK region
• A method to search for correlations of ultra-high energy cosmic ray masses with the large scale structures in the local galaxy density field
• Nuclear collision in strong magnetic field
• Constraints on Physical Conditions for the Acceleration on Ultra-high-energy Cosmic Rays in Nearby Active Galactic Nuclei Observed with the Fermi Large Area Telescope
• Directional correlations between UHECRs and neutrinos observed with IceCube
• The 320 EeV Fly's Eye event: a key messenger or a statistical oddity ?
• Past, Present and Future of UHECR Observations
• Olber's Paradox for Superluminal Neutrinos: Constraining Extreme Neutrino Speeds at TeV-ZeV Energies with the Diffuse Neutrino Background
• UHECRs mass composition from $X_{\max }$ distributions
• Bilateral constraints on proton Lorentz violation effects
• Spectra and Mass Composition of Ultrahigh-Energy Cosmic Rays from Point Sources
• Scaling Violation and Inelasticity of Very High Energy Proton-Proton Interactions
• The MIDAS Experiment: A New Technique for the Detection of Extensive Air Showers
• Report from the Multi-Messenger Working Group at UHECR-2014 Conference
• Propagation of UHECRs in the Universe
• Large-Scale Distribution of Arrival Directions of Cosmic Rays Detected at the Pierre Auger Observatory Above $10$PeV
• Maximum entropy analysis of cosmic ray composition
• Feynman scaling violation due to baryon number diffusion in rapidity space
• The Energy Spectrum of Ultra-High-Energy Cosmic Rays Measured by the Telescope Array FADC Fluorescence Detectors in Monocular Mode
• On the influence of statistics on the determination of the mean value of the depth of shower maximum for ultra high energy cosmic ray showers
• Disentangling the Air Shower Components Using Scintillation and Water Cherenkov Detectors
• Particle Interactions in Matter at the Terascale: the Cosmic-Ray Experience
• Study of Galactic interactions and propagation properties of ultrahigh energy cosmic rays using the precision spectrum from the Pierre Auger Observatory
• Energy spectrum and mass composition of the primary cosmic rays based on the intensity of muon bundles detected in the NEVOD-DECOR experiment
• Fitting fractions of the $X_{\max }$ distributions at ultra high energies
• UHECR primary identification using the lateral profile of muons in EAS
• A method to calibrate the absolute energy scale of air showers with ultra-high energy photons