Measurements of the cosmic-ray air-shower fluorescence at extreme energies require precise knowledge of atmospheric conditions. The absolute calibration of the cosmic-ray energy depends on the ...absorption of fluorescence light between its origin and point of its detection. To reconstruct basic atmospheric parameters we review a novel analysis method based on two- and multi-angle measurements performed by the scanning backscatter lidar system. Applied inversion methods, optical depth, absorption and backscatter coefficient, as well as other parameters that enter the lidar equation are discussed in connection to the attenuation of the light traveling from shower to fluorescence detector.
The LIDAR systems for atmospheric monitoring in Auger Mussa, R.; Argiró, S.; Cester, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2004, Letnik:
518, Številka:
1
Journal Article
Recenzirano
A LIDAR network is being built for the measurement and online monitoring of the atmospheric optical parameters, which play a central role in the energy measurement of ultra-high-energy cosmic rays. ...Four LIDAR systems, each one equipped by an Nd:YAG UV laser and three parabolic mirrors with PMTs for the detection of the backscatter photons, are scheduled to be installed in the proximity of the four fluorescence detectors of the Pierre Auger Observatory (Malargüe, Argentina). In this paper a report describing hardware components, commissioning and shooting strategies of the LIDAR systems is given.
We have improved by two orders of magnitude the limit currently available for the CPT violation parameter Re(
δ). To this purpose we have analyzed the full sample of neutral-kaon decays to e
πν ...recorded in the CPLEAR experiment, where the strangeness of the neutral kaons was tagged at production and decay time. An appropriate function of the measured decay rates, including information from the analysis of π
+π
− decay channel, gives directly Re(
δ). The result Re(
δ)=(3.0±3.3
stat±0.6
syst)×10
−4 is compatible with zero. Values for the parameters Im(
δ), Re(
x
−) and Im(
x
+) were also obtained.
Data from the CPLEAR experiment, together with the most recent world averages for some of the neutral-kaon parameters, were constrained with the Bell–Steinberger (or unitarity) relation, allowing the ...T-violation parameter Re(
ϵ) and the CPT-violation parameter Im(
δ) of the neutral-kaon mixing matrix to be determined with an increased accuracy: Re(
ϵ)=(164.9±2.5)×10
−5, Im(
δ)=(2.4±5.0)×10
−5. Moreover, the constraint allows the CPT-violation parameter for the neutral-kaon semileptonic decays, Re(
y), to be determined for the first time. The
ΔS≠
ΔQ parameters Re(
x
−) and Im(
x
+) are given with an increased accuracy. The quantity Re(
y+
x
−), which enters the T-violation CPLEAR asymmetry previously published, is determined to be (−0.2±0.3)×10
−3. The value obtained for Re(
δ) is in agreement with the one resulting from a previous unconstrained fit and has a slightly smaller error.
The Lidar system of the Pierre Auger Observatory BenZvi, S.Y.; Cester, R.; Chiosso, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2007, Letnik:
574, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The Pierre Auger Observatory in Malargüe, Argentina, is designed to study the origin of ultrahigh energy cosmic rays with energies above
10
18
eV
. The energy calibration of the detector is based on ...a system of four air fluorescence detectors. To obtain reliable calorimetric information from the fluorescence stations, the atmospheric conditions at the experiment's site need to be monitored continuously during operation. One of the components of the observatory's atmospheric monitoring system is a set of four elastic backscatter lidar stations, one station at each of the fluorescence detector sites. This paper describes the design, current status, standard operation procedure, and performance of the lidar system of the Pierre Auger Observatory.
We report on a new measurement of the K
L–K
S mass difference
Δm using the CPLEAR full data sample of neutral-kaon decays to e
πν. The result is
Δm=(0.5295±0.0020
stat±0.0003
syst)×10
10 ℏ/s. It ...includes earlier data reported in R. Adler et al., CPLEAR Collaboration, Phys. Lett. B 363 (1995) 237. A measurement of the
ΔS=
ΔQ violating parameter Re(
x) is also obtained.
We report a measurement of the CP violation parameter
η
+− from the time-dependent asymmetry between the decay rates of initially tagged K
0 and
K
0
. The results are based on the complete data ...sample collected by the CPLEAR collaboration. With
Δm=(530.1±1.4)×10
7ℏs
−1 and
τ
S=(89.34±0.08) ps, the values obtained are |
η
+−|=(2.264±0.023
stat±0.026
syst±0.007
τ
S
)×10
−3 and
φ
+−=43.19°±0.53°
stat±0.28°
syst±0.42°
Δm
.
We test the Principle of Equivalence for particles and antiparticles, using CPLEAR data on tagged K
0 and
K
0
decays into
π
+
π
−. For the first time, we search for possible annual, monthly and ...diurnal modulations of the observables |
η
+−| and
φ
+−, that could be correlated with variations in astrophysical potentials. Within the accuracy of CPLEAR, the measured values of |
η
+−| and
φ
+− are found not to be correlated with changes of the gravitational potential. We analyze data assuming effective scalar, vector and tensor interactions, and we conclude that the Principle of Equivalence between particles and antiparticles holds to a level of 6.5, 4.3 and 1.8×10
−9, respectively, for scalar, vector and tensor potentials originating from the Sun with a range much greater than the distance Earth–Sun. We also study energy-dependent effects that might arise from vector or tensor interactions. Finally, we compile upper limits on the gravitational coupling difference between K
0 and
K
0
as a function of the scalar, vector and tensor interaction range.
The Pierre Auger observatory Zavrtanik, D
Nuclear physics. Section B, Proceedings supplement,
05/2000, Letnik:
85, Številka:
1
Journal Article
We present the scientific motivation, conceptual design and status of the P. Auger Observatory, a hybrid detector designed to measure both the longitudinal and the lateral profile of giant ...air-showers produced by cosmic-rays of energy above 10
19 eV. Two ground arrays of water Čerenkov tanks overlooked by fluorescence detectors will cover an area of 3000
km
2 each. They will be build in the Southern and Northern hemisphere to provide full sky coverage. The total aperture of 14000
km
2
sr will allow to study all observable aspects of cosmic rays from below 10 EeV up to arbitrarily high energies with an unprecedented accuracy.
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