0000000001225605
AUTHOR
S. D Amico
Testing Hadronic Interactions at Ultrahigh Energies with Air Showers Measured by the Pierre Auger Observatory
Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on the absolute energy calibration, and apply it to events with primary energy 6-16 EeV (ECM=110-170 TeV), whose longitudinal development and lateral distribution were simultaneously measured by the Pierre Auger Observatory. The average hadronic shower is 1.33±0.16 (1.61±0.21) times larger than predicted using the leading LHC-tuned models EPOS-LHC (QGSJetII-04), with a corresponding excess of muons.
Search for photons with energies above 1018 eV using the hybrid detector of the Pierre Auger Observatory
A search for ultra-high energy photons with energies above 1 EeV is performed using nine years of data collected by the Pierre Auger Observatory in hybrid operation mode. An unprecedented separation power between photon and hadron primaries is achieved by combining measurements of the longitudinal air-shower development with the particle content at ground measured by the fluorescence and surface detectors, respectively. Only three photon candidates at energies 1-2 EeV are found, which is compatible with the expected hadron-induced background. Upper limits on the integral flux of ultra-high energy photons of 0.027, 0.009, 0.008, 0.008 and 0.007 km-2 sr-1 yr-1 are derived at 95% C.L. for ener…
Bio-based Materials. Standardizzazione e processi per la commercializzazione
Il contributo si occupa degli aspetti normativi nel campo della produzione e uso di una malta con componenti organici derivanti dal riciclo di scarti agricoli e silvo-pastorali. Viene prestata attenzione alla normativa internazionale più diffusa e nota, a quella europea e a quella italiana. La riduzione del consumo di suolo e di risorse lapidee, degli scarti, la limitazione dell’utilizzo di materiali di cava naturali sono solo alcuni benefici che hanno indotto la comunità scientifica a investire nell’uso di materie prime-seconde di origine vegetale, ecosostenibili; oggi, lo stato dell’arte è molto ricco. Tuttavia, non ci sono ancora normative tecniche e procedurali relative ai materiali che…