scholarly journals Investigating the influence of diffractive interactions on ultrahigh-energy extensive air showers

2018 ◽  
Vol 33 (26) ◽  
pp. 1850153 ◽  
Author(s):  
L. B. Arbeletche ◽  
V. P. Gonçalves ◽  
M. A. Müller

The understanding of the basic properties of the ultrahigh-energy extensive air showers is dependent on the description of hadronic interactions in an energy range beyond that probed by the LHC. One of the uncertainties present in the modeling of air showers is the treatment of diffractive interactions, which are dominated by nonperturbative physics and usually described by phenomenological models. These interactions are expected to affect the development of the air showers, since they provide a way of transporting substantial amounts of energy deep in the atmosphere, modifying the global characteristics of the shower profile. In this paper, we investigate the impact of diffractive interactions in the observables that can be measured in hadronic collisions at high energies and ultrahigh-energy cosmic ray interactions. We consider three distinct phenomenological models for the treatment of diffractive physics and estimate the influence of these interactions on the elasticity, number of secondaries, longitudinal air shower profiles and muon densities for proton-air and iron-air collisions at different primary energies. Our results demonstrate that even for the most recent models, diffractive events have a non-negligible effect on the observables and that the distinct approaches for these interactions, present in the phenomenological models, still are an important source of theoretical uncertainty for the description of the extensive air showers.

2019 ◽  
Vol 210 ◽  
pp. 02012
Author(s):  
R. Takeishi

One of the uncertainties in ultrahigh energy cosmic ray (UHECR) observation derives from the hadronic interaction model used for air shower Monte-Carlo (MC) simulations. One may test the hadronic interaction models by comparing the measured number of muons observed at the ground from UHECR induced air showers 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 UHECRs 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. 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 proton-induced showers. The same feature was also obtained for other hadronic interaction models, such as QGSJET II-04.


2019 ◽  
Vol 197 ◽  
pp. 02001
Author(s):  
Bianca Keilhauer

The Pierre Auger Observatory for detecting ultrahigh energy cosmic rays has been founded in 1999. After a main planning and construction phase of about five years, the regular data taking started in 2004, but it took another four years until the full surface detector array was deployed. In parallel to the main detectors of the Observatory, a comprehensive set of instruments for monitoring the atmospheric conditions above the array was developed and installed as varying atmospheric conditions influence the development and detection of extensive air showers. The multitude of atmospheric monitoring installations at the Pierre Auger Observatory will be presented as well as the challenges and efforts to run such instruments for several decades.


2019 ◽  
Vol 208 ◽  
pp. 02002
Author(s):  
Tanguy Pierog

The interpretation of EAS measurements strongly depends on detailed air shower simulations. CORSIKA is one of the most commonly used air shower Monte Carlo programs. The main source of uncertainty in the prediction of shower observables for different primary particles and energies is currently dominated by differences between hadronic interaction models even after recent updates taking into account the first LHC data. As a matter of fact the model predictions converged but at the same time more precise air shower and LHC measurements introduced new constraints. Last year a new generation of hadronic interaction models was released in CORSIKA. Sibyll 2.3c and DPMJETIII.17-1 are now available with improved descriptions of particle production and in particular the production of charmed particles. The impact of these hadronic interaction models on air shower predictions are presented here and compared to the first generation of post-LHC models, EPOS LHC and QGSJETII-04. The performance of the new models on standard air shower observables is derived. Due to the various approaches in the physics treatment, there are still large differences in the model predictions but this can already be partially resolved by comparison with the latest LHC data.


2021 ◽  
Vol 81 (4) ◽  
Author(s):  
Á. Pastor-Gutiérrez ◽  
H. Schoorlemmer ◽  
R. D. Parsons ◽  
M. Schmelling

AbstractIn the sub-TeV regime, the most widely used hadronic interaction models disagree significantly in their predictions for post-first interaction and ground-level particle spectra from cosmic ray induced air showers. These differences generate an important source of systematic uncertainty in their experimental use. We investigate the nature and impact of model uncertainties through a simultaneous analysis of ground level particles and first interaction scenarios. We focus on air shower primaries with energies close to the transition between high and low energy hadronic interaction models, where the dissimilarities have been shown to be the largest and well within the range of accelerator measurements. Interaction models are shown to diverge as several shower scenarios are compared, reflecting intrinsic differences in the model theoretical frameworks. Finally, we discuss the importance of interactions in the energy regime where the switching between models occurs ($$<1$$ < 1  TeV) and the effect of the choice of model on the number of hadronic interactions within cosmic ray induced air showers of higher energies.


2019 ◽  
Vol 208 ◽  
pp. 05003
Author(s):  
Hans P. Dembinski

The LHCb experiment is designed to study flavor physics of b and c quarks. The detector is optimized for the study of identified hadrons produced in the forward direction, which also makes LHCb very interesting for the understanding of cosmic-ray induced air showers. LHCb is analysing proton-proton, protonlead, and lead-lead collisions. As a unique feature, LHCb is also studying beam interactions with noble gases using its SMOG system. We present recent measurements of charmed mesons, which are used to obtain production cross-sections, to constrain the parton PDF, to test pomeron and multi-particle interactions, nuclear and collective effects. These mostly have an indirect impact on the modeling of hadronic interactions. Finally, we present a direct measurement of the anti-proton production in proton collisions with helium gas, which are important for the understanding of AMS-02 and PAMELA data.


1977 ◽  
Vol 55 (14) ◽  
pp. 1280-1288 ◽  
Author(s):  
Gary R. Smith ◽  
S. Standil

A search for tachyons preceding extensive air showers has been conducted using an air shower array operated in conjunction with a large aperture, five element cosmic ray telescope. More than 200 000 air showers of primary energy [Formula: see text] were observed over a period of 223 days and a 290 μs period before each of these showers was scanned for a related particle signal from the telescope. In this way a particle arrival time spectrum containing 1519 tachyon candidates was observed. No convincing evidence was found for any subgroup of these events that might be attributable to tachyons.


2019 ◽  
Vol 208 ◽  
pp. 15005
Author(s):  
Hans P. Dembinski

The LHCb experiment is designed to study flavor physics of b and c quarks. The detector is optimized for the study of identified hadrons produced in the forward direction, which also makes LHCb very interesting for the understanding of cosmic-ray induced air showers. LHCb is analysing proton-proton, protonlead, and lead-lead collisions. As a unique feature, LHCb is also studying beam interactions with noble gases using its SMOG system. We present recent measurements of charmed mesons, which are used to obtain production cross-sections, to constrain the parton PDF, to test pomeron and multi-particle interactions, nuclear and collective effects. These mostly have an indirect impact on the modeling of hadronic interactions. Finally, we present a direct measurement of the anti-proton production in proton collisions with helium gas, which are important for the understanding of AMS-02 and PAMELA data.


2019 ◽  
Vol 208 ◽  
pp. 08003 ◽  
Author(s):  
Raul R. Prado

The hybrid design of the Pierre Auger Observatory allows for the measurement of a number of properties of extensive air showers initiated by ultra-high energy cosmic rays. By comparing these measurements to predictions from air shower simulations, it is possible to both infer the cosmic ray mass composition and test hadronic interactions beyond the energies reached by accelerators. In this paper, we will present a compilation of results of air shower measurements by the Pierre Auger Observatory which are sensitive to the properties of hadronic interactions and can be used to constrain the hadronic interaction models. The inconsistencies found between the interpretation of different observables with regard to primary composition and between their measurements and simulations show that none of the currently used hadronic interaction models can provide a proper description of air showers and, in particular, of the muon production.


1976 ◽  
Vol 54 (2) ◽  
pp. 176-185 ◽  
Author(s):  
Gary R. Smith ◽  
S. Standil

A large aperture, five element cosmic ray telescope was operated in conjunction with an air shower array in a search for long lived particles, delayed between 1 and 45 μs after extensive air showers. After sampling ~ 29 000 air showers with an energy greater than ~ 1014 eV, over a period of 9 months, an excess of 11 such events were observed with time delays in the interval of 1 to 6 μs following the showers. The events in the remainder of the 45 μs interval were consistent with background random coincidences. We estimate that only 1 of the 11 excess events might be attributable to afterpulsing in our telescope photomultiplier tubes. All the excess 'trailing particle' events can be explained as being due to electrons resulting from shower associated muons that stop and decay in the vicinity of the cosmic ray telescope.


2005 ◽  
Vol 20 (29) ◽  
pp. 6814-6816
Author(s):  
A. GERANIOS ◽  
E. FOKITIS ◽  
S. MALTEZOS ◽  
K. PATRINOS ◽  
A. DIMOPOULOS

Using the AIRES code, we have generated a large number of Extensive Air Showers corresponding to Ultra high energy cosmic ray gammas, protons and iron nuclei with energy range 1015 – 1022 eV. These simulations clearly show the different atmospheric depths of the Extensive Air Shower maxima in this energy range.


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