1,847 research outputs found
Constraints and measurements of hadronic interactions in extensive air showers with the Pierre Auger Observatory
The characteristics of extensive air showers are sensitive to the details of
hadronic interactions at energies and in kinematic regions beyond those tested
by human-made accelerators. Uncertainties on extrapolations of the hadronic
interaction models in these regions hamper the interpretation of the ultra high
energy cosmic ray data in terms of primary mass composition. We report on how
the Pierre Auger Observatory is able to constrain the hadronic interaction
models by measuring the muon content and muon production depth of air showers
and also by measuring the proton-air cross section for particle production at a
center-of-mass energy per nucleon of 57 TeV.Comment: Proceedings of the 13th International Conference on Topics in
Astroparticle and Underground Physics, Asilomar, California USA. (TAUP2013
Hadronic physics with the Pierre Auger Observatory
Extensive air showers are the result of billions of particle reactions initiated by single cosmic rays at ultra-high energy. Their characteristics are sensitive both to the mass of the primary cosmic ray and to the fine details of hadronic interactions. Ultra-high energy cosmic rays can be used to experimentally extend our knowledge on hadronic interactions in energy and kinematic regions beyond those tested by human-made accelerators. We report on how the Pierre Auger Observatory is able to measure the proton-air cross section for particle production at a center-of-mass energy per nucleon of 39 TeV and 56 TeV and also to constrain the new hadronic interaction models tuned after the results of the Large Hadron Collider, by measuring: the average shape of the electromagnetic longitudinal profile of air showers, the moments of the distribution of the depth at which they reach their maximum, and the content and production depth of muons in air showers with a primary center-of-mass energy per nucleon around and above the 100 TeV scale.Peer Reviewe
Constraints and measurements of hadronic interactions in extensive air showers with the Pierre Auger Observatory
The characteristics of extensive air showers are sensitive to the details of hadronic interactions at energies and in kinematic regions beyond those tested by human-made accelerators. Uncertainties on extrapolations of the hadronic interaction models in these regions hamper the interpretation of the ultra high energy cosmic ray data in terms of primary mass composition. We report on how the Pierre Auger Observatory is able to constrain the hadronic interaction models by measuring the muon content and muon production depth of air showers and also by measuring the proton-air cross section for particle production at a center-of-mass energy per nucleon of 57 TeV.Peer Reviewe
A model for the transport of muons in extensive air showers
In this article we identify the key elements that govern the propagation of
muons from the production in extensive air showers to ground. We describe a
model based on simple assumptions that propagates the muons starting from the
few relevant distributions at production. We compare the results to the ground
distributions given by a full air shower Monte Carlo. This study is motivated
by the need of modeling the muon component in extensive air showers with the
goal of experimentally reconstructing their distributions at production, which
act as a footprint of the hadronic cascade
Sensitivity of EAS measurements to the energy spectrum of muons
We have studied how the energy spectrum of muons at production affects some of the most common measurements related to muons in extensive air shower studies, namely, the number of muons at the ground, the slope of the lateral distribution of muons, the apparent muon production depth, and the arrival time delay of muons at ground. We found that by changing the energy spectrum by an amount consistent with the difference between current models (namely EPOS-LHC and QGSJ et -II.04), the muon surface density at ground increases 5% at 20° zenith angle and 17% at 60° zenith angle. This effect introduces a zenith angle dependence on the reconstructed number of muons which might be experimentally observed. The maximum of the muon production depth distribution at 40° increases ∼ 10 g/cm 2 and ∼ 0 g/cm 2 at 60°, which, from pure geometrical considerations, increases the arrival time delay of muons. There is an extra contribution to the delay due to the subluminal velocities of muons of the order of ∼ 3 ns at all zenith angles. Finally, changes introduced in the logarithmic slope of the lateral density function are less than 2%.Peer Reviewe
Depth Development of Extensive Air Showers from Muon Time Distributions
We develop a potential algorithm to relate the depth development of ultra
high energy extensive air showers and the time delay for individual muons. The
time distributions sampled at different positions at ground level by a large
air shower array are converted into distributions of production distances using
an approximate relation between production distance, transverse distance and
time delay. The method is naturally restricted to inclined showers where muons
dominate the signal at ground level but could be extended to vertical showers
provided that the detectors used can separate the muon signal from electrons
and photons. We explore the accuracy and practical uncertainties involved in
the proposed method. For practical purposes only the muons that fall outside
the central region of the shower can be used, and we establish cuts in
transverse distance. The method is tested using simulated showers by comparing
the production distance distributions obtained using the method with the actual
distances in the simulated showers. It could be applied in the search of
neutrinos to increase the acceptance to highly penetrating particles, as well
as for unraveling the relative compositions of protons and heavy nuclei. We
also illustrate that the obtained depth distributions have minimum width when
both the arrival direction and the core position are well reconstructed.Comment: 16 pages, 11 figures. Accepted for publication in Astropart. Phy
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