G.C. Trinchero

Limits on low-energy neutrino fluxes with the Mont Blanc liquid scintillator detector

Abstract The LSD liquid scintillation detector has been operating since 1985 as an underground neutrino observatory in the Mont Blanc Laboratory with the main objective of detecting antineutrino bursts from collapsing stars. In August 1988 the construction of an additional lead and borex paraffin shield considerably reduced the radioactive background and increased the sensitivity of the apparatus. In this way the search for steady fluxes of low-energy neutrinos of different flavours through their interactions with free protons and carbon nuclei of the scintillator was made possible. No evidence for a galactic collapse was observed during the whole period of measurement. The corresponding 90% c.l. upper limit on the galactic collapses rate is 0.45 y −1 for a burst duration of ΔT ⩽ 10 s. After analysing the last 3 years data, the following 90% c.l. upper limits on the steady neutrino and antineutrino fluxes were obtained: Φ( \ gn e ) 4 \ gn e s −1 cm −2 9 ⩽ E ν ⩽ 50MeV Φ( \ gn e ) 3 \ gn e s −1 cm −2 20 ⩽ E ν ⩽ 50MeV Φ(ν e ) 3 ν e s −1 cm −2 25 ⩽ E ν ⩽ 50 MeV Φ(ν μ + τ ) 7 ν μ + τ s −1 cm −2 20 ⩽ E ν ⩽ 100 MeV Φ( \ gn μ + τ ) 7 \ gn μ + τ s −1 cm −2 20 ⩽ E ν ⩽ 100 MeV In particular comparing the obtained upper limit on the \ gn e flux for 9 ⩽ E ν ⩽ 20 MeV to the solar ν e flux predicted by the standard solar model in the same range of energy, we can exclude the possibility that more than 6.3% of the solar ν e s flux can change to \ gn e . Finally the first limits on the flux of relic supernova neutrinos of all flavours as a function of the neutrino sea temperature are presented.

The limit to the UHE extraterrestrial neutrino flux from the observations of horizontal air showers at EAS-TOP

Abstract Extensive Air Showers at large zenith angles θ > 70° (Horizontal Air Showers, HAS) are observed at the EAS-TOP array at Campo Imperatore (Gran Sasso Laboratories). The rate of these events exceeds the one due to primary cosmic rays (at this angles) and therefore these showers have to be generated by penetrating particles. Assuming that they are produced by atmospheric muons we derived the muon flux as Fμ(> 30 TeV) = 1.1 × 10−11cm−2s−1sr−1, in good agreement with the underground measurements. The upper limits for diffuse neutrino radiation from these measurements is Iν(> 105GeV) dI ν e (E 0 )/dE ν e −18 cm −2 s −1 sr −1 GeV −1 , for the resonant ( E 0 = m W 2 2m e = 6.4 × 10 6 GeV ) neutrinos.

Upper limit on the prompt muon flux derived from the LVD underground experiment

We present the analysis of the muon events with all muon multiplicities collected during 21804 hours of operation of the first LVD tower. The measured depth-angular distribution of muon intensities has been used to obtain the normalization factor, A, the power index, gamma, of the primary all-nucleon spectrum and the ratio, R_c, of prompt muon flux to that of pi-mesons - the main parameters which determine the spectrum of cosmic ray muons at the sea level. The value of gamma = 2.77 +/- 0.05 (68% C.L.) and R_c<2.0 x 10^-3 (95% C.L.) have been obtained. The upper limit to the prompt muon flux favours the models of charm production based on QGSM and the dual parton model.

Experimental Study of Upward Stopping Muons in NUSEX

A search for upward-going stopping muon events has been performed using the NUSEX detector. The experimental flux (1.31???0.46)???10-13??/cm2 s sr is in good agreement with the theoretical expectations of muon production from atmospheric neutrinos. The experimental limit on the flux of muons produced by high-energy neutrinos from the Sun is compared to the expectations based on cold-dark-matter hypothesis, and mass limits on different candidates are set.

Search for fractionally charged particles in the Mont Blanc LSD scintillation detector

Abstract An analysis of the events recorded by the Mont Blanc Neutrino Scintillation Detector was performed in order to search for fractionally charged particles with |Q| = 1 3 and |Q| = 2 3 . In a live time of 2378 days, the obtained 90% C. L. upper limits on the fluxes of fractionally charged particles in the core of our detector are Φ(|Q| = 1 3 ) −13 cm −2 s −1 sr −1 and Φ(|Q| = 2 3 ) −13 cm −2 s −1 sr −1 , the best available limits obtained by scintillation counters technique.

Study of single muons with the Large Volume Detector at the Gran Sasso Laboratory

The present study is based on the sample of 2.9×106 single muons observed by the Large Volume Detector (LVD) at the underground Gran Sasso Laboratory during 36 500 live hours from June 1992 to February 1998. We have measured the muon intensity at slant depths from 3 to 20 km w.e. Most events are high-energy downward muons produced by meson decay in the atmosphere. The analysis of these muons has revealed the power index γ of the π and K spectrum: γ=2.76±0.05. The remainders are horizontal muons produced by the neutrino interactions in the rock surrounding the LVD. The value of this flux near 90° is (6.1±2.7)×10−13 cm−2 s−1 sr−1. The results are compared with the Monte Carlo simulations and the world data.

High modularity fast charge-time digitizer in neutrino burst detection

Abstract A 1 MHz high modularity electronic system for large-volume detectors in the search for neutrino bursts from stellar collapses has been developed. Technical details and final results of tests performed on the prototypes are presented.

Comparison of lopes measurements with coreas and reas 3.11 simulations

In the previous years, LOPES emerged as a very successful experiment measuring the radio emission from air showers in the MHz frequency range. In parallel, the theoretical description of radio emission was developed further and REAS became a widely used simulation Monte Carlo code. REAS 3 as well as CoREAS are based on the endpoint formalism, i.e. they calculate the emission of the air-shower without assuming specific emission mechanisms. While REAS 3 is based on histograms derived from CORSIKA simulations, CoREAS is directly implemented into CORSIKA without loss of information due to histogramming of the particle distributions. In contrast to the earlier versions of REAS, the newest version REAS 3.11 and CoREAS take into account a realistic atmospheric refractive index. To improve the understanding of the emission processes and judge the quality of the simulations, we compare their predictions with high-quality events measured by LOPES. We present results concerning the lateral distribution measured with...

The KASCADE‐Grande Experiment

KASCADE-Grande is the enlargement of the KASCADE extensive air shower detector, realized to expand the cosmic ray studies from the previous 10–10 eV primary energy range to 10 eV. This is performed by extending the area covered by the KASCADE electromagnetic array from 200 200 to 700 700 m by means of 37 scintillator detector stations of 10 m area each. This new array is named Grande and provides measurements of the all-charged particle component of extensive air showers (Nch), while the original KASCADE array particularly provides information on the muon content ðNmÞ. Additional dense compact detector set-ups being sensitive to energetic hadrons and muons are used for data consistency checks and calibration purposes. The performance of the Grande array and its integration into the entire experimental complex is discussed. It is demonstrated that the overall observable resolutions are adequate to meet the physical requirements of the measurements, i.e. primary energy spectrum and elemental composition studies in the primary cosmic ray energy range of 10–10 eV. & 2010 Elsevier B.V. All rights reserved.

Effects of the new hadronic interaction models on the reconstruction of KASCADE-Grande observables

A. Gherghel-Lascu∗5, W.D. Apel1, J.C. Arteaga-Velázquez2, K. Bekk1, M. Bertaina3, J. Blümer1,4, H. Bozdog1, I.M. Brancus5, E. Cantoni3,6, A. Chiavassa3, F. Cossavella4, K. Daumiller1, V. de Souza7, F. Di Pierro3, P. Doll1, R. Engel1, D. Fuhrmann8, H.J. Gils1, R. Glasstetter8, C. Grupen9, A. Haungs1, D. Heck1, J.R. Hörandel10, D. Huber4, T. Huege1, K.-H. Kampert8, D. Kang4, H.O. Klages1, K. Link4, P. Łuczak11, H.J. Mathes1, H.J. Mayer1, J. Milke1, B. Mitrica5, C. Morello6, J. Oehlschläger1, S. Ostapchenko12, N. Palmieri4, T. Pierog1, H. Rebel1, M. Roth1, H. Schieler1,S. Schoo1, F.G. Schröder1, O. Sima13, G. Toma5, G.C. Trinchero6, H. Ulrich1, A. Weindl1, J. Wochele1, J. Zabierowski11 KASCADE-Grande