SEARCH FOR 100 TEV GAMMA-RAY EMISSION FROM THE GALACTIC DISK

A search for UHE (greater-than-or-equal-to 100 TeV) diffuse gamma-ray emission from the Galactic disk has been carried out, through the excess in the cosmic-ray counting rate, by means of the EAS-TOP extensive air shower array at the Gran Sasso Laboratories. Measurements are performed from angular scales /b/ almost-equal-to 2-degrees (as in 100 MeV satellite experiments, and as expected from CR interactions with the ISM) to /b/ almost-equal-to 100. The obtained upper limits (90% c.l.) to the gamma-ray excess over the cosmic-ray flux from the Galactic disk region are I(gamma)/I(p) 130 TeV, corresponding to upper limits to the flux of I(gamma) < 3.2 x 10(-13) cm-2 s-1 rad-1, I(gamma) < 2.8 x 10(-13) cm-2 s- 1 rad-1, and I(gamma) < 4 x 10(-13) cm-2 S-1 rad-1.3971114815

UHE COSMIC-RAY EVENT RECONSTRUCTION BY THE ELECTROMAGNETIC DETECTOR OF EAS-TOP

UHE cosmic rays are studied by means of the detectors of the different components of secondaries produced by their interactions in the atmosphere (EAS). We describe and discuss the reconstruction techniques and accuracies of the e.m. detector of EAS-TOP. They allow, besides independent high resolution measurements of UHE gamma-ray astronomy, good correlation possibilities with the detectors of the different EAS components.3364167131032

Experimental study of hadronic interaction model using coincident data from EAS-TOP and MACRO

The contemporaneous measurement of TeV muons in deep underground laboratories and of the e.m. component at the surface allows checking the hadron interaction models and the propagation codes used in EAS experiments in a primary energy range 10–50 TeV in which the primary spectra are measured by direct experiments. First results of such measurements between MACRO and EAS-TOP at the Gran Sasso laboratory, in this energy range, are here reported

SINGLE MUONS IN THE LARGE-VOLUME DETECTOR

The first angular distribution data from 5547 hours of operation of the LVD detector are presented. A total of 452,630 single muons were reconstructed for this period. We present, for the first time from Gran Sasso Laboratory, data at near-horizontal zenith angles.3524024

MULTIPLE MUON EVENTS OBSERVED IN THE LVD EXPERIMENT

This is a progress report on the multiple muon events recorded by the first tower of the LVD detector at the Gran Sasso Laboratory. About 17,000 multiple muon events have been observed since the LVD first tower started operation in June 1992. Presented here are the measured multiplicity distribution and separation distribution of muon pairs in the bundles.3524324

SEARCH FOR NEUTRINOS FROM COLLAPSING STARS WITH THE LVD AT GRAN-SASSO

The Large Volume Detector (LVD) in the Gran Sasso underground Laboratory is a multipurpose detector consisting of a large volume of liquid scintillator interleaved with limited streamer tubes. In this paper we discuss its power to study low energy cosmic neutrinos. The results show that the first of the five LVD towers, operational since June 1992 with 368 tons of liquid scintillator, is well suited to detect neutrinos from collapsing stars within all our Galaxy, over a wide range of burst duration (up to a few hundreds seconds). One year data, collected since June 1992, have been analized and results are here discussed. No evidence for burst candidates has been found in this period of data taking.3526726

Single muon angular distributions observed in the LVD particle astrophysics experiment

The first angular distribution data from 5547 hours of operation of the LVD detector are presented. The technique of track reconstruction is described. A total of 452 657 single muons were reconstructed for this period. The data are acceptance corrected in our final plots. The total single muon flux (the total flux from above impinging on a sphere of unit cross sectional area) in the Gran Sasso Laboratory is 1.03 muons per hour per square meter. The total flux crossing a unit horizontal area from above is 0.79 muons per hour per square meter. The acceptance-corrected intensity at cos theta = 1 is 0.349 muons per hour per square meter per steradian (9.7 x 10(-9) muons per second per square centimeter per steradian). We present, for the first time from Gran Sasso Laboratory, data at near-horizontal zenith angles.22103116Italian Institute for Nuclear Physics (INFN)US Department of EnergyUS National Science FoundationState of Texas under its TATRP progra

MEASUREMENT OF ELECTROMAGNETIC AND TEV MUON COMPONENTS OF EXTENSIVE AIR SHOWERS BY EAS-TOP AND MACRO EXPERIMENTS

The simultaneous observation of the electromagnetic and TeV muon components of extensive air showers by the EAS-TOP and MACRO detectors, respectively, is described for a period of 100 days in 1990. The two detectors and their combined resolutions are briefly reviewed and muon multiplicity distributions for various detector configurations are presented. A first analysis of the physical parameters N(mu) and N(e) related to the study of the primary composition at E0 = 10(14) - 10(16) eV is also presented

THE LARGE-VOLUME DETECTOR (LVD) - A MULTIPURPOSE UNDERGROUND DETECTOR AT GRAN-SASSO

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