The Large Volume Detector (LVD) in the INFN Gran Sasso National Laboratory, Italy, is a ν observatory mainly designed to study low energy neutrinos from the gravitational collapse of galactic objects. The experiment has been monitoring the Galaxy since June 1992, under increasing larger configurations: in January 2001 it has reached its final active mass M = 1 kt. LVD is one of the largest liquid scintillator apparatus for the detection of stellar collapses and, besides SuperKamiokande and Amanda, it is a member of the SNEWS network, that has become fully operational since July 1st, 2005. During 2008 there was a long run of the CNGS project: LVD was fully operative; we report about the detected CNGS events. 1 The LVD experiment 1.1 Scientific ground The Large Volume Detector (LVD), located in the hall A of the INFN Gran Sasso National Laboratory, Italy, is a multipurpose detector consisting of 1000 tons of liquid scintillator arranged in a compact and modular geometry (a front view is shown in fig.1). The major purpose of the LVD experiment is the search for neutrinos from Gravitational Stellar Collapses (GSC) in our Galaxy [1]. Indeed, in spite of the lack of a “standard” model of the gravitational collapse of a massive star, the correlated neutrino emission appears to be well established. At the end of its burning phase a massive star (M > 8M⊙) explodes into a supernova, originating a neutron star which cools emitting its binding energy EB ∼ 3·10 53 erg mostly in neutrinos. The largest part of this energy, almost equipartitioned among neutrino and antineutrino species, is emitted in the cooling phase: Eν̄e ∼ Eνe ∼ Eνx ∼ EB/6 (where νx denotes generically νμ, ν̄μ, ντ , ν̄τ flavors). The energy spectra are approximatively a Fermi-Dirac distribution, with different mean temperatures, since νe, ν̄e and νx have different couplings with the stellar matter: Tνe < Tν̄e < Tνx . Figure 1: Front view of the LVD detector in the hall A of the Gran Sasso National Laboratory, INFN. LVD is able to detect ν̄e interactions with protons in the scintillator, which give the main signal of supernova neutrinos, with a very good signature. Moreover, it can detect νe

1. AbstractThe Large Volume Detector LVD (Gran Sasso National Laboratory, Italy),is a neutrino telescope mainly designed to search for low energy neutrino burstsfrom Gravitational Stellar Collapses (GSC) in the Galaxy. The experiment hasbeen monitoring the Milky Way since June 1992 under increasing larger config-urations, reaching in January 2001 the final active mass of 1000 t. No burstcandidate has been detected over all the ten years of observation: we present herethe obtained limit to the rate of SuperNova (SN) event in the galaxy.

The results of the analysis of events recorded by the LVD neutrino detector at Gran Sasso Laboratory during the maximum peak of the high solar activity (including the very intense Bastille solar flare) are reported. The analysis of

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.

The detection of Gamma Ray Burst GRB 990705 on 1999, July 5.66765 UT, pointing to the Large Magellanic Clouds, suggested the search for a possible neutrino counterpart, both in coincidence with and slightly before (or after) the photon burst. We exploited such a possibility by means of the LVD neutrino telescope (National Gran Sasso Laboratory, Italy), which has the capability to study low-energy cosmic neutrinos. No evidence for any neutrino signal, over a wide range of time durations, has been found, at the occurrence of GRB 990705. Due to the lack of information about both the source distance and its emission spectrum, the results of the search are expressed in terms of upper limits, at the Earth, to the flux cross-section, integrated over different time durations, . Moreover, assuming thermal spectra at the source, upper limits to the flux, integrated over time duration, for different spectral temperatures, are obtained. Based on these limits and on the expectations for ν emission from collapsing astrophysical objects, the occurrence of a gravitational stellar collapse can be excluded up to a distance kpc, in the case of time coincidence with GRB 990705, and kpc, for the 24 hours preceding it.

The detection of Gamma Ray Burst GRB 990705 on 1999, July 5.66765 UT, pointing to the Large Magellanic Clouds, suggested the search for a possible neutrino counterpart, both in coincidence with and slightly before (or after) the photon burst. We exploited such a possibility by means of the LVD neutrino telescope (National Gran Sasso Laboratory, Italy), which has the capability to study low-energy cosmic neutrinos. No evidence for any neutrino signal, over a wide range of time durations, has been found, at the occurrence of GRB 990705. Due to the lack of information about both the source distance and its emission spectrum, the results of the search are expressed in terms of upper limits, at the Earth, to the nu (e) flux cross-section, integrated over different time durations, integral integral Phi nu (e)sigma dEdt. Moreover, assuming thermal nu (e) spectra at the source, upper limits to the nu (e) flux, integrated over time duration, for different spectral temperatures, are obtained. Based on these limits and on the expectations for nu emission from collapsing astrophysical objects, the occurrence of a gravitational stellar collapse can be excluded up to a distance r approximate to 50 kpc, in the case of time coincidence with GRB 990705, and r approximate to 20 kpc, for the 24 hours preceding it.

The Large Volume Detector (LVD) in the Gran Sasso Underground Laboratory, Italy, is a neutrino observatory mainly devoted to detect low energy ν from gravitational collapses of galactic objects. The experiment, which at the present time has an active mass M = 1000 tons, has been taking data, under ever increasing mass configurations, since 1992, with a sensitivity high enough to cover the Galaxy. Results of the monitoring, based on ever larger statistics, have already been reported: no candidates for supernova ν bursts have been found. We update here the analysis up to December 2000, presenting the results of the search based on the sets of data taken in 1999 and 2000 (592 days of live-time). The new upper limit (based on 2691 days of observation) on the rate of stellar collapses in the Milky Way is0.3 event per year.

The detection of Gamma Ray Burst GRB990705 on 1999, July 5.66765 UT, pointing to the Large Magellanic Clouds, suggested the search for a possible neutrino counterpart, both in coincidence with and slightly before (or after) the photon burst. We Exploited such a possibility by means of the LVD neutrino telescope (National Gran Sasso Laboratory, Italy), which has the capability to study low-energy cosmic neutrinos. No evidence for any neutrino signal, over a wide range of time durations, has been found at the occurrence of GRB990705. Due to the lack of information about both the source distance and its emission spectrum, the results of the search are expressed ill terms of upper limits, at the Earth, to the (v) over bar (e) flux . cross-section, integrated over different time durations, integral integral Phi(v) over bar (e) sigma dEdt. Moreover, assuming thermal v, spectra at the source, upper limits to the v, flux, integrated over time duration, for different spectral temperatures, are obtained. Based on these limits and on the expectations for v emission from collapsing astrophysical objects, the occurrence of a gravitational stellar collapse can be excluded up to a distance r approximate to 50 kpc, in the case of time coincidence with GRB990705, and r approximate to 20 kpc, for the 24 hours preceding it.

The detection of Gamma Ray Burst GRB 990705 on 1999, July 5.66765 UT, pointing to the Large Magellanic Clouds, suggested the search for a possible neutrino counterpart, both in coincidence with and slightly before (or after) the photon burst. We exploited such a possibility by means of the LVD neutrino telescope (National Gran Sasso Laboratory, Italy), which has the capability to study low-energy cosmic neutrinos. No evidence for any neutrino signal, over a wide range of time durations, has been found, at the occurrence of GRB 990705. Due to the lack of information about both the source distance and its emission spectrum, the results of the search are expressed in terms of upper limits, at the Earth, to the ν̄e flux · cross-section, integrated over different time durations, ∫ ∫ Φν̄eσdEdt. Moreover, assuming thermal ν̄e spectra at the source, upper limits to the ν̄e flux, integrated over time duration, for different spectral temperatures, are obtained. Based on these limits and on the expectations for ν emission from collapsing astrophysical objects, the occurrence of a gravitational stellar collapse can be excluded up to a distance r ≈ 50 kpc, in the case of time coincidence with GRB 990705, and r ≈ 20 kpc, for the 24 hours preceding it.

In the energy region 10 - 100 TeV both the c.r. composition from direct measurements and the cross section for high energy secondary production in the very forward region for p-air interactions are rather uncertain. Contemporaneous measurements of the total energy and of the threshold energy/nucleon of the primary particle can be provided by the atmospheric Cherenkov light and high energy muons. These measurements are performed by the combined operation of the Cherenkov array of the EAS-TOP experiment on the surface (810 gcm(2) atmospheric depth) and of the LVD experiment in the underground Gran Sasso Laboratories (3300 m w.e.; E-mu(th) = 1.3 TeV) leading to the measurement of < N-mu > (E-mu > 1.3 TeV, E-o) in the given energy range. The combined operation of the experiments and preliminary results are reported.

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.

We present an analysis of muon events with all muon multiplicities collected during 21804 h of operation of the first Large Volume Detector tower. The measured angular distribution of muon intensity has been converted to the "depth-vertical-intensity" relation in the depth range from 3 to 12 km w.e. The analysis of this relation allowed us to derive the power index gamma of the primary all-nucleon spectrum: gamma = 2.78 +/- 0.05. The "depth-vertical-intensity" relation has been converted to standard rock and the comparison with the data of other experiments has been done. We also present the derived vertical muon spectrum at sea level. [S0556-2821(98)00517-7].

We present evidence for a dependence of the average deep underground muon energies on shower size in the coincident EAS-TOP and LVD data at the Gran Sasso laboratories. The measured relation agrees with a mixed chemical composition of the cosmic ray primary spectrum at energies around 1015 eV.