Study of the effect of neutrino oscillation on the supernova neutrino signal with the LVD detector

We present an update of our previous study (astro-ph/0112312) on how $\nu$ oscillations affect the signal from a supernova core collapse observed in the LVD detector at LNGS. In this paper we use a recent, more precise determination of the cross section (astro-ph/0302055) to calculate the expected number of inverse beta decay events, we introduce in the simulation also the $\nu$-{\rm Fe} interactions, we include the Earth matter effects and, finally, we study also the inverted mass hierarchy case.Comment: 4 pages, 4 figures, to appear in the Proceedings of ICRC 200

Study of the effect of neutrino oscillations on the supernova neutrino signal in the LVD detector

The LVD detector, located in the INFN Gran Sasso National Laboratory (Italy), studies supernova neutrinos through the interactions with protons and carbon nuclei in the liquid scintillator and interactions with the iron nuclei of the support structure. We investigate the effect of neutrino oscillations in the signal expected in the LVD detector. The MSW effect has been studied in detail for neutrinos travelling through the collapsing star and the Earth. We show that the expected number of events and their energy spectrum are sensitive to the oscillation parameters, in particular to the mass hierarchy and the value of $\theta_{13}$, presently unknown. Finally we discuss the astrophysical uncertainties, showing their importance and comparing it with the effect of neutrino oscillations on the expected signal.Comment: Accepted for pubblication on Astroparticle Physics. 36 pages, 18 figure

Heart rhythm safety of the mononuclear cord blood stem cells transplantation in patients with refractory ischemic heart failure

The aim – to evaluate the safety of mononuclear cord blood stem cells transplantation regarding influence upon heart rhythm in patients with refractory heart failure Materials and methods. The work is based on the analysis of Holter-ECG monitoring data in 20 patients with refractory heart failure and reduced myocardial contractility. With the purpose of improvement of systolic function patients underwent transplantation of mononuclear cord blood stem cells. Results. Analysis of the probable proarrhythmogenic influence of mononuclear cord blood stem cells was performed in terms of follow-up during up to 9 months. Results demonstrated that administration of the cell preparation «Cryopreserved human cord blood» is not associated with increased risk of life-threatening cardiac arrhythmias. Conclusions.Transplantation of mononuclear cord blood stem cells should not be considered as an additional arrhythmogenic risk factor in patients with refractory heart failure

Characterisation of Cu(In,Ga)Se-2-based thin film solar cells on polyimide

Thin films of Cu(In,Ga)Se2 (CIGS) were deposited at temperatures below 450 °C on polyimide (PI) substrates coated with Mo in a roll-to-roll set up by a combination of co-evaporation and ion-beam techniques. Flexible solar cells ITO/i-ZnO/CdS/CIGS/Mo/PI with and without Na incorporation were then fabricated. The films and solar cells were examined by: X-ray fluorescence spectroscopy (XRF) and Auger electron spectroscopy (AES), to determine the elemental composition, as well as by X-ray diffraction for structure- and scanning electron microscopy (SEM) for morphology-analysis. Photoluminescence (PL) and PL-excitation (PLE) at temperatures from 4.2 to 78 K were also used to estimate the band-gap energy of CIGS, examine the electronic properties and defect nature. The aim of this study was to correlate the incorporation of Na with optical and structural parameters of the CIGS layers as well as with the solar cell performance

Search for correlations between GW detectors and the LVD neutrino telescope

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CNGS beam monitor with the LVD detector

The importance of an adequate CNGS beam monitor at the Gran Sasso Laboratory has been stressed in many papers. Since the number of internal νμ CC and NC interactions in the various detectors will not allow rapid collection of statistics, one should also be able to detect the νμ CC interactions in the upstream rock. In this study we have investigated the performances of the LVD detector as a monitor for the CNGS neutrino beam. Thanks to its wide area (13 711 m2 orthogonal to the beam direction), LVD can detect about 120 muons per day originated by νμ CC interactions in the rock. The LVD total mass is ∼ 2 kt. This allows obtaining 30 more CNGS events per day as internal (NC + CC) νμ interactions, for a total of ∼ 150 events per day. A 3% statistical error can be reached in 7 days. Taking into account the time characteristics of the CNGS beam, the cosmic muon background can be reduced to a negligible level, of the order of 1.5 events per day

Analysis of Cosmogenic Neutron Characteristics and the Pulses Counting Rate Using ASD, LSD, and LVD Scintillation Detectors

International audienceExperimental data obtained using three scintillation detectors are analyzed. The characteristics of cosmogenic neutrons in underground experiments their analytic dependences are considered. The behavior of background counting rate for the LVD detector for two measuring thresholds (0.5 and 5 MeV) are discussed

Characterization of the varying flux of atmospheric muons measured with the Large Volume Detector for 24 years

International audienceThe Large Volume Detector, hosted in the INFN Laboratori Nazionali del Gran Sasso, is triggered by atmospheric muons at a rate of ∼0.1  Hz. The data collected over almost a quarter of a century are used to study the muon intensity underground. The 5×107 muon series, the longest ever exploited by an underground instrument, allows for the accurate long-term monitoring of the muon intensity underground. This is relevant as a study of the background in the Gran Sasso Laboratory, which hosts a variety of long-duration, low-background detectors. We describe the procedure to select muon-like events as well as the method used to compute the exposure. We report the value of the average muon flux measured from 1994 to 2017: Iμ0=3.35±0.0005stat±0.03sys×10-4  m-2 s-1. We show that the intensity is modulated around this average value due to temperature variations in the stratosphere. We quantify such a correlation by using temperature data from the European Center for Medium-range Weather Forecasts: we find an effective temperature coefficient αT=0.94±0.01stat±0.01sys, in agreement with other measurements at the same depth. We scrutinize the spectral content of the time series of the muon intensity by means of the Lomb-Scargle analysis. This yields the evidence of a 1-year periodicity, as well as the indication of others, both shorter and longer, suggesting that the series is not a pure sinusoidal wave. Consequently, and for the first time, we characterize the observed modulation in terms of amplitude and position of the maximum and minimum on a year-by-year basis