scholarly journals Simulation study on the effects of diffractive collisions on the prediction of the observables in ultra-high-energy cosmic ray experiments

2021 ◽  
Author(s):  
Ken Ohashi ◽  
Hiroaki Menjo ◽  
Yoshitaka Itow ◽  
Takashi Sako ◽  
Katsuaki Kasahara
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Mass Composition ◽  
Ultra High Energy ◽  
Hadronic Interaction ◽  
Open Problems ◽  
Cross Sectional ◽  
High Energy Cosmic Rays ◽  
The Cross ◽  
Mass Dependent

Abstract The mass composition of ultra-high-energy cosmic rays is important for understanding their origin. Owing to our limited knowledge of the hadronic interaction, the interpretations of the mass composition from observations include several open problems, such as the inconsistent interpretations of ⟨Xmax⟩ and ⟨Xμmax⟩. Futhermore, the large difference between the predictions exists by the hadronic interaction models. Diffractive collision is one of the proposed sources of the uncertainty. In this paper, we discuss the effect of the detailed characteristics of diffractive collisions to the observables of ultra-high-energy cosmic-ray experiments, focusing on three detailed characteristics. These are the cross-sectional fractions of different collision types, diffractive-mass spectrum, and diffractive-mass-dependent particle productions from the diffractive dissociation system. We demonstrated that the current level of the uncertainty in the cross-sectional fraction can affect 8.9 g/cm2 of ⟨Xmax⟩ and 9.4 g/cm2 of ⟨Xμmax⟩, whereas the other details of the diffractive collisions exhibit relatively minor effects.

scholarly journals Methods to measure the cosmic-ray composition with the Auger Engineering Radio Array

2019 ◽  
Vol 216 ◽  
pp. 02004 ◽  
Author(s):  
Fabrizia Canfora
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Mass Composition ◽  
Atmospheric Depth ◽  
Ultra High Energy ◽  
Air Showers ◽  
Radio Stations ◽  
High Energy Cosmic Rays ◽  
Air Shower ◽  
Number Of Particles

The mass composition of ultra-high-energy cosmic rays plays a key role in the understanding of the origins ofthese rare particles. A composition-sensitive observable is the atmospheric depth at which the air shower reaches the maximum number of particles (Xmax). The Auger Engineering Radio Array (AERA) detects the radio emission inthe 30-80 MHz frequency band from extensive air showers with energies larger than 1017 eV. It consists of more than 150 autonomous radio stations covering an area of about 17 km2. From the distribution of signals measured by the antennas, it is possible to estimate Xmax. In this contribution three independent methods for the estimation of Xmax will be presented.

scholarly journals Observation of ultra-high energy cosmic rays with the Telescope Array experiment

2018 ◽  
Vol 182 ◽  
pp. 02122
Author(s):  
Ryuji Takeishi
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
High Energy ◽  
Mass Composition ◽  
Ultra High Energy ◽  
Air Showers ◽  
Telescope Array ◽  
High Energy Cosmic Rays ◽  
Fluorescence Light ◽  
Hybrid Detector

The origin of ultra-high energy cosmic rays (UHECRs) has been a longstanding mystery. The Telescope Array (TA) is the largest experiment in the northern hemisphere observing UHECR in Utah, USA. It aims to reveal the origin of UHECR by studying the energy spectrum, mass composition and anisotropy of cosmic rays. TA is a hybrid detector comprised of three air fluorescence stations which measure the fluorescence light induced from cosmic ray extensive air showers, and 507 surface scintillator counters which sample charged particles from air showers on the ground. We present the cosmic ray spectrum observed with the TA experiment. We also discuss our results from measurement of the mass composition. In addition, we present the results from the analysis of anisotropy, including the excess of observed events in a region of the northern sky at the highest energy. Finally, we introduce the TAx4 experiment which quadruples TA, and the TA low energy extension (TALE) experiment.

scholarly journals Study of muons in extensive air showers from ultra-high energy cosmic rays measured with the Telescope Array experiment

2019 ◽  
Vol 208 ◽  
pp. 08004
Author(s):  
R. Takeishi
Keyword(s):  
Cosmic Rays ◽  
High Energy ◽  
Extensive Air Showers ◽  
Mass Composition ◽  
Ultra High Energy ◽  
Air Showers ◽  
Hadronic Interaction ◽  
Telescope Array ◽  
Interaction Models ◽  
High Energy Cosmic Rays

The origin of ultra-high energy cosmic rays (UHECRs) has been a long-standing mystery. One of the uncertainties in UHECR observation derives from the hadronic interaction model used for air shower Monte-Carlo (MC) simulations. The number of muons observed at ground level from UHECR induced air showers is expected to depend upon the composition of primary cosmic rays. The MC prediction also depends on hadronic interaction models. One may test the hadronic interaction models by comparing the measured number of muons with the MC prediction. The Telescope Array (TA) is the largest experiment in the northern hemisphere observing UHECR in Utah, USA. It aims to reveal the origin of UHECR by studying the energy spectrum, mass composition and anisotropy of cosmic rays by utilizing an array of surface detectors (SDs) and fluorescence detectors. We studied muon densities in the UHE extensive air showers by analyzing the signal of TA SD stations for highly inclined showers which should have high muon purity. A high muon purity condition is imposed that requires the geometry of the shower and relative position of the given station and implies that muons dominate the signal. On condition that the muons contribute about 65% of the total signal, the number of particles from air showers is typically 1.88 ± 0.08(stat:) ± 0.42(syst:) times larger than the MC prediction with the QGSJET II-03 model for protons. The same feature was also obtained for other hadronic models, such as QGSJET II-04.

scholarly journals High energy cosmic ray interactions and UHECR composition problem

2019 ◽  
Vol 210 ◽  
pp. 02001
Author(s):  
Sergey Ostapchenko
Keyword(s):  
Experimental Data ◽  
Monte Carlo ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Hadronic Interactions ◽  
High Energy Cosmic Rays ◽  
Cosmic Ray Interactions ◽  
Composition Problem

The differences between contemporary Monte Carlo generators of high energy hadronic interactions are discussed and their impact on the interpretation of experimental data on ultra-high energy cosmic rays (UHECRs) is studied. Key directions for further model improvements are outlined. The prospect for a coherent interpretation of the data in terms of the UHECR composition is investigated.

scholarly journals Cosmic ray transport and anisotropies to high energies

2015 ◽  
Vol 2 ◽  
pp. 39-44 ◽  
Author(s):  
P. L. Biermann ◽  
L. I. Caramete ◽  
A. Meli ◽  
B. N. Nath ◽  
E.-S. Seo ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Wave Number ◽  
Ultra High Energy ◽  
Galactic Magnetic Field ◽  
Chemical Abundances ◽  
High Energy Cosmic Rays ◽  
High Energies ◽  
Isotropic Approximation ◽  
Galactic Cosmic Ray

Abstract. A model is introduced, in which the irregularity spectrum of the Galactic magnetic field beyond the dissipation length scale is first a Kolmogorov spectrum k-5/3 at small scales λ = 2 π/k with k the wave-number, then a saturation spectrum k-1, and finally a shock-dominated spectrum k-2 mostly in the halo/wind outside the Cosmic Ray disk. In an isotropic approximation such a model is consistent with the Interstellar Medium (ISM) data. With this model we discuss the Galactic Cosmic Ray (GCR) spectrum, as well as the extragalactic Ultra High Energy Cosmic Rays (UHECRs), their chemical abundances and anisotropies. UHECRs may include a proton component from many radio galaxies integrated over vast distances, visible already below 3 EeV.

ULTRA HIGH ENERGY COSMIC RAYS WITH THE PIERRE AUGER OBSERVATORY

2012 ◽  
Vol 18 ◽  
pp. 221-229
Author(s):  
◽  
J. R. T. DE MELLO NETO
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Cross Section ◽  
High Energy ◽  
Pierre Auger Observatory ◽  
Mass Composition ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
The Status ◽  
Shower Maximum

We present the status and the recent measurements from the Pierre Auger Observatory. The energy spectrum is described and its features discussed. We report searches for anisotropy of cosmic rays arrival directions in large scales and through correlation with catalogues of celestial objects. The measurement of the cross section proton-air is discussed. Finally, the mass composition is addressed with the measurements of the variation of the depth of shower maximum with energy and with the muon density at ground.

scholarly journals Ultra High Energy Cosmic Rays: Origin, Composition and Spectrum

2019 ◽  
Vol 209 ◽  
pp. 01018
Author(s):  
Roberto Aloisio
Keyword(s):  
Cosmic Rays ◽  
Gamma Rays ◽  
Theoretical Models ◽  
High Energy ◽  
Experimental Results ◽  
Mass Composition ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
Secondary Particles

The physics of Ultra High Energy Cosmic Rays will be reviewed, discussing the latest experimental results and theoretical models aiming at explaining the observations in terms of spectra, mass composition and possible sources. It will be also discussed the emission of secondary particles such as neutrinos and gamma rays produced by the interaction of Ultra High Energy Cosmic Rays with astrophysical photon backgrounds. The content of the present proceeding paper is mainly based on the review papers [1, 2].

scholarly journals The Pierre Auger Observatory: Review of Latest Results and Perspectives

Universe ◽  
2018 ◽  
Vol 4 (11) ◽  
pp. 128 ◽  
Author(s):  
Dariusz Góra ◽  
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Detection System ◽  
Cosmic Ray ◽  
High Energy ◽  
Pierre Auger Observatory ◽  
Mass Composition ◽  
Ultra High Energy ◽  
Energy Limitation ◽  
Arrival Directions

The Pierre Auger Observatory is the world’s largest operating detection system for the observation of ultra high energy cosmic rays (UHECRs), with energies above 10 17 eV. The detector allows detailed measurements of the energy spectrum, mass composition and arrival directions of primary cosmic rays in the energy range above 10 17 eV. The data collected at the Auger Observatory over the last decade show the suppression of the cosmic ray flux at energies above 4 × 10 19 eV. However, it is still unclear if this suppression is caused by the energy limitation of their sources or by the Greisen–Zatsepin–Kuzmin (GZK) cut-off. In such a case, UHECRs would interact with the microwave background (CMB), so that particles traveling long intergalactic distances could not have energies greater than 5 × 10 19 eV. The other puzzle is the origin of UHECRs. Some clues can be drawn from studying the distribution of their arrival directions. The recently observed dipole anisotropy has an orientation that indicates an extragalactic origin of UHECRs. The Auger surface detector array is also sensitive to showers due to ultra high energy neutrinos of all flavors and photons, and recent neutrino and photon limits provided by the Auger Observatory can constrain models of the cosmogenic neutrino production and exotic scenarios of the UHECRs origin, such as the decays of super heavy, non-standard-model particles. In this paper, the recent results on measurements of the energy spectrum, mass composition and arrival directions of cosmic rays, as well as future prospects are presented.

scholarly journals Measurements of UHECR Mass Composition by Telescope Array

2019 ◽  
Vol 210 ◽  
pp. 01008
Author(s):  
William Hanlon
Keyword(s):  
Monte Carlo ◽  
Cosmic Ray ◽  
High Energy ◽  
Mass Composition ◽  
Ultra High Energy ◽  
Fluorescence Detector ◽  
Telescope Array ◽  
Second Moments ◽  
Systematic Uncertainties ◽  
Surface Detector

Telescope Array (TA) has recently published results of nearly nine years of Xmax observations providing its highest statistics measurement of ultra high energy cosmic ray (UHECR) mass composition to date for energies exceeding 1018.2 eV. This analysis measured agreement of observed data with results expected for four different single elements. Instead of relying only on the first and second moments of Xmax distributions, we employ a morphological test of agreement between data and Monte Carlo to allow for systematic uncertainties in data and in current UHECR hadronic models. Results of this latest analysis and implications of UHECR composition observed by TA are presented. TA can utilize different analysis methods to understand composition as both a crosscheck on results and as a tool to understand systematics affecting Xmax measurements. The different analysis efforts utilizing fluorescence detector stereo, surface detector and fluorescence detector hybrid, and surface detector-only, currently underway at TA performed to understand composition are also discussed.

Sign in / Sign up

Export Citation Format

Share Document