206 research outputs found
The Southern Wide-field Gamma-ray Observatory
The Southern Wide-field Gamma-ray Observatory (SWGO) is an R&D project to
plan and design the next observatory to detect gamma rays in the Southern
hemisphere. The experiment, planned to be placed at an altitude greater than
4400 m, is primarily based on water Cherenkov detectors units and is expected
to measure gamma rays from a few hundred GeV up to the PeV scale. SWGO will
complement CTA and the existing ground-based particle detectors of the Northern
Hemisphere, namely HAWC and LHAASO, having a rich science programme. The
collaboration is highly invested in evaluating different detector and array
configurations, prototyping, and site search. In this presentation, I shall
present an overview of the project's activities, achievements and future plans.Comment: General overview presentation at the ICRC2
High-energy interactions at the Pierre Auger Observatory
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 opportunity to explore hadronic interactions at the highest energies. However, the extraction of hadronic interaction properties from the Extensive Air Showers (EAS) characteristics, which are induced by the UHECR, is intrinsically related to the nature of the primary cosmic ray. As such, to break the degeneracy between hadronic interactions and primary mass composition, a consistent description of the shower observables must be achieved. Such detailed studies have been conducted in the last years at the Pierre Auger Observatory, the largest UHECRs detector in the world. It combines two complementary techniques to measure the EAS characteristics. In this talk, we will present the latest measurements on shower observables, both on the electromagnetic and muonic shower components, and its interpretation in terms of the primary mass composition. Its impact regarding particle physics will be discussed, in particular the measurement of the proton-air cross section. Finally, through the joint analysis of the different measurements, it will be shown that none of the post-LHC high-energy hadronic interaction models can satisfactorily describe the data.Peer Reviewe
The interplay between the electromagnetic and the muonic longitudinal profile at production
The electromagnetic and the muonic longitudinal profile at production
enclosure important information about the primary particle and the hadronic
interactions that rule the shower development. In fact, these two profiles
provide two different insights of the shower: the electromagnetic component
gives a measurement of the energy and the strength of the neutral pion channel;
while the muonic profile, being intimately related with the charged mesons
decays, can be used as a direct probe for the high energy hadronic
interactions.
In this work we explore the interplay between the electromagnetic and muonic
profiles, by analysing their phenomenologic behaviour for different primary
masses and energies, zenith angles, and also different high energy hadronic
interaction models. We have found that the muonic longitudinal profile at
production displays universal features similar to what is known for the
electromagnetic one. Moreover, we show that both profiles have new primary mass
composition variables which are fairly independent of the high energy hadronic
interaction model.
Finally we discuss how the information in the electromagnetic and the muonic
longitudinal profile can be combined to break the degeneracy between the
primary mass composition and the high energy hadronic physics.Comment: 5 pages, to appear in conference proceedings of International
Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI 2012),
Berlin, German
Probing the spectrum at high- in proton-Air interactions at ultra-high energies
The average number of muons in air showers and its connection with shower
development has been studied extensively in the past. With the upcoming
detector upgrades, UHECR observatories will be able to probe higher moments of
the distribution of the number of muons. Here a study of the physics of the
fluctuations of the muon content is presented. In addition to proving that the
fluctuations must be dominated by the first interactions, we show that
low- tail of the shower-to-shower distribution of the number of muons
is determined by the high- region of the production cross-section of
neutral pions in the first interaction.Comment: Proceedings of Ultra High Energy Cosmic Rays 201
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