The EAS-TOP array, located at Campo Imperatore, 2000 m a.s.l., 30° respect to the vertical to the underground Gran Sasso Laboratories, has been in operation between 1989 and 2000 to study cosmic rays ...in the energy region between 10
13 and 10
16 eV. The energy range overlaps the direct measurements and extends to above the knee of the primary spectrum. We summarize here some results obtained on cosmic ray primaries and the methods used to check the consistency of the description of hadronic interactions in such an energy range.
The Auger Surface Detector consists of a large array of water Cherenkov detector tanks each with a volume of 12,000
l, for the detection of high energy cosmic rays. The accuracy in the measurement of ...the integrated signal amplitude of the detector unit has been studied using experimental air shower data. It can be described as a Poisson-like term with a normalization constant that depends on the zenith angle of the primary cosmic ray. This dependence reflects the increasing contribution to the signal of the muonic component of the shower, both due to the increasing muon/electromagnetic (
e
±
and
γ
) ratio and muon track length with zenith angle.
In order to confirm the existence of strange quark matter (SQM) in cosmic rays, a series of international balloon flights with a hybrid system combining active counters and passive detectors was ...conducted under the collaboration between Japan and Italy. In this report, the methodology of how to detect SQM with the hybrid system and how to determine
Z/
β with CR-39 track detectors are presented.
Inelastic interactions of muons in the NUSEX detector located at a depth of about 5000 hg/cm
2
have been analysed. Distributions of secondary hadrons in range and fly-out angle have been measured. ...The possible contribution of hadrons emitted at large angles to the background flux of upward-going particles in underground neutrino experiments is discussed.
The most recent experimental results on the cosmic ray composition and energy spectrum above 1 TeV are reviewed and discussed. All data agree on the presence of the so-called “knee” at an energy
E
κ ...⋍ 3 10
15
eV; the knee is seen in all the components of the Extensive Air Showers. These results support the hypothesis of an astrophysical origin of the knee, while no new features in the hadronic interactions at high energies are envisaged. The cosmic ray composition below and above the knee region is still an open question. According to most experiments, the knee seems to be due to the light component of the primary beam, with a composition getting heavier above the knee. However, results contradicting this conclusion have to be considered and understood.
An upper limit to the flux of Ultra High Energy (UHE) γ-rays in the primary cosmic radiation is obtained through the data of the electromagnetic and the muon detectors of the EAS-TOP Extensive Air ...Shower array (Campo Imperatore, National Gran Sasso Laboratories, atmospheric depth 810g cm
−2). The search is performed by selecting Extensive Air Showers (EAS) with low muon content. For EAS electron sizes
N
e
> 6.3 · 10
5, no showers are observed with the core located inside a fiducial area and no muons recorded in the 140 m
2 muon detector, during a live time of 8440 h. The 90% c.l. upper limit to the relative intensity of γ-ray with respect to cosmic ray (c.r.) primaries is
I
γ
I
c.r.
< 7.3·10
−5
, at primary energy
E
0 ≥ 10
15 eV: this limit is lower than reported in previous measurements.
Multiple electromagnetic interactions of high energy cosmic ray muons in the NUSEX detector (5000 mwe underground) have been analysed. Different modes of the pair meter technique have been used to ...investigate the muon energy spectrum shape at the observation depth. The observed event distributions are in good agreemetn with the expectation based on the usual picture of underground muon spectra. The first experimental estimates of the muon spectrum parameters at great depths have been obtained. A comparison of the estimated average muon energy with the available theoretical calculations is given.
PDF
