Results on high-energy cosmic rays by EAS-TOP at Gran Sasso

Very High-Energy cosmic rays have to be studied through the ground-based detectors of the Extensive Air Showers (EAS) that they produce in the atmosphere. The main measurements to be performed are of: primary energy spectra, composition, anisotropies, «neutral primary» astronomy, and interaction properties. This requires complete detectors of all the EAS components, and for this purpose the EAS-TOP array has been constructed at Campo Imperatore (2000 m a.s.l.) on top of the Gran Sasso underground laboratories. The array has been progressively going into operation since 1988. In this paper we present the status and performances of the different detectors, and the results obtained up to now on the different items under discussion

Search For 100 Tev Gamma-ray Emission From the Galactic Disk

Upper limits have been obtained to the diffuse gamma-ray emission from the Galactic disk. The limits I(gamma)/I(p) less than 0.2 percent, i.e., I(gamma)(greater than 130 TeV) less than 3.2 x 10 exp -13/q cm/s/rad provide the first measurement obtained in the angular window corresponding to the distribution of the ISM. It is still, however, a factor of about 30 higher than the flux calculated from the cosmic ray interactions by Berezinsky and Kudryavtsev (1990). A lower limit of gamma greater than 2.3 is obtained to the power-law index of the differential energy spectrum of Galactic gamma rays from 100 MeV to 100 TeV, setting a limit to the possibility of a hard extrapolation of the Galactic gamma-ray spectrum to the 100 TeV region. 21 refs

Eas Cherenkov At Gran Sasso: Correlated Observations At The Surface And With Deep Underground Events

We present the first results of the observations of the atmospheric Cherenkov light emission from Extensive Air Showers, obtained from the EAS-TOP experiment at Campo Imperatore (at the Gran Sasso Laboratory). Data concern measurements at low energies, and the correlations with the e.m. and GeV muon detectors at the surface, and with the events observed deep underground (LVD detector). © 1992 Società Italiana di Fisica.105121806181

Search For 100 Tev γ-ray Emission From The Galactic Disk

A search for UHE (≥ 100 TeV) diffuse γ-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| ≈ 2° (as in 100 MeV satellite experiments, and as expected from CR interactions with the ISM) to |b| ≈ 10°. The obtained upper limits (90% c.l.) to the γ-ray excess over the cosmic-ray flux from the Galactic disk region are Iγ/Ip < 0.2% for |b| < 2°, Iγ/Ip < 0.04% for |b| < 5°, and Iγ/Ip < 0.02% for |b| < 12° at E0 > 130 TeV, corresponding to upper limits to the flux of Iγ < 3.2 × 10-13 cm-2 s-1 rad-1, Iγ < 2.8 × 10-13 cm-2 s-1 rad-1, and Iγ < 4 × 10-13 cm-2 s-1 rad-1.3971148152DMS; Division of Mathematical SciencesAglietta, M., (1986) Nuov. Cimento, 9 C, p. 262(1988) Nucl. Instr. Meth., A277, p. 23(1989) Istituto di Cosmogeofisica del CNR Internal Report, 213 (89)(1991) 22d Internat. Cosmic Ray Conf. (Dublin), 4, p. 512Matthews, J., (1991) High Energy Gamma-Ray Astronomy, p. 145. , New York: AIP(1991) 22d Internat. Cosmic Ray Conf. (Dublin), 1, p. 404(1991) 22d Internat. Cosmic Ray Conf. (Dublin), 2, p. 708Alexeenko, V.V., Navarra, G., (1985) Lett. Nuov. Cimento, 42, p. 321Bellolti, R., (1990) Phys. Rev D., 42, p. 1396Berezinsky, V. S. 1990, preprint1991, preprintBerezinsky, V.S., Kudryavtsev, V.A., (1990) ApJ, 349, p. 620Bloemen, J.B.G.M., (1987) ApJ, 317, pp. L15Clay, R.W., Protheroe, R.J., Gerhardy, P.R., (1984) Nature, 309, p. 687Dowthwaite, J.C., (1985) A&A, 142, p. 55Ellis, J., Gelmini, G. B., Lopez, J. L., Nanopoulos, D. V., & Sarkar, S. 1990, preprintFomin, V.P., Vladimirsky, A.A., Stepanian, A.A., (1977) 15th Internat. Cosmic Ray Conf. (Plovdiv), 1, p. 12Hartman, R.C., (1979) ApJ, 230, p. 597Kraushaar, W.L., (1972) ApJ, 177, p. 341Lambert, A., Lloyd-Evans, J., Watson, A.A., (1983) 18th Internat. Cosmic Ray Conf. (Bangalore), 9, p. 219Matthews, J., (1991) ApJ, 375, p. 202Mayer-Hasselwander, H.A., (1982) A&A, 105, p. 164Morello, C., Periale, L., Vallania, P., Navarra, G., (1987) Nuov. Cimento, 10, p. 37Reynolds, P.T., Fegan, D.J., Harris, K., Lang, M.J., Vacanti, G., Weekes, T.C., (1990) 21st Internat. Cosmic Ray Conf. (Adelaide), 2, p. 183Weekes, T.C., Helmken, H.F., L'Heureux, J., (1979) 16th Internat. Cosmic Ray Conf. (Kyoto), 1, p. 13

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 γ-ray astronomy, good correlation possibilities with the detectors of the different EAS components. © 1993.33601/02/15310321Aglietta, (1986) Nuovo Cimento, 9 C, p. 262Anglietta, The EAS-TOP array at : Stability and resolutions (1988) Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 277, p. 23Aglietta, (1992) Nuovo Cimento C, 15, p. 735Aglietta, Studies of muons and of electromagnetic component of extensive air showers at EAS-TOP (1993) Proc. 23rd ICRC, Calgary, 4, p. 251Aglietta, Imaging of atmospheric EAS Cherenkov light at EAS-TOP (1992) Il Nuovo Cimento C, 100 15, p. 357Aglietta, (1992) Nuovo Cimento, 105 A, p. 1807Castagnoli, (1991) Proc. 22nd ICRC, 4, p. 363. , Dublin, IrelandBellotti, (1990) Phys. Rev., 42 D, p. 1396Aglietta, (1992) Nuovo Cimento, 105 A, p. 1815Cocconi, (1961) Handbuch der Physik 46/1, , Springer, BerlinJames, Roos, MINUIT Function Minimization and Error Analysis (1989) CERN Program Library, 506 D. , Release 89.12jNelson, (1985) The EGS4 Code System, SLAC-265Aglietta, (1991) Proc. 22nd ICRC, 2, p. 708. , Dublin, IrelandAglietta, The EAS primary spectrum between 1014 and 1016 eV (EAS-TOP data) (1993) Proc. 23rd ICRC, Calgary, 4, p. 247Aglietta, Study of EAS Cherenkov light images at EAS-TOP (1993) Proc. of 23rd ICRC, Calgary, 4, p. 700Constraints on the PeV cosmic ray composition and interaction models from coincident EAS-TOP and MACRO data (1993) Proc. 23rd ICRC, Calgary, 2, p. 89Surface and deep underground observations of extensive air showers (1993) Proc. 23rd ICRC, Calgary, 4, p. 696Aglietta, UHE γ-ray astronomy with the EAS-TOP array (1993) Proc. 23rd ICRC, Calgary, , in pressAglietta, (1992) Astrophys. J., 397, p. 148Aglietta, Study of horizontal air showers from EAS-TOP (1993) Proc. 23rd ICRC, Calgary, 4, p. 25