[Show abstract][Hide abstract] ABSTRACT: An overview of the studies for the ATLAS Event Filter is given.
The architecture and the high level design of the DAQ-1 prototype is
presented. The current status if the prototypes is briefly given.
Finally, future plans and milestones are given
[Show abstract][Hide abstract] ABSTRACT: The MACRO underground detector at Gran Sasso has recorded about 30 million muon events in the period 1989-1995. We have analyzed these data to look for time variations and to study the pointing capabilities of the apparatus in the search for astrophysical point sources. We have observed a 3% seasonal variation of the high energy muon rate, due to atmospheric temperature variations, in agreement with theoretical predictions. We report also the detection of the moon shadowing effect with a statistical significance of 3.7sigma. The results obtained straighten the possibility that a ``muon astronomy'' using underground experiments is possible.
No preview · Article · Jan 1998 · Nuclear Physics B - Proceedings Supplements
[Show abstract][Hide abstract] ABSTRACT: A transition radiation detector (TRD) consisting of three identical modules each of 12 m2 area, has been developed and installed on the MACRO detector at the Gran Sasso National Laboratory. The modular structure, based on single proportional tubes and polyethylene foam radiators, allows to cover a large area. The TRD measures the residual energies (up to 1 TeV) of penetrating muons at the MACRO depth. Calibrations from prototypes operated in a test beam at the CERN P.S. are quoted. The author presents preliminary data from the first TRD module, collected in a period of about one year.
[Show abstract][Hide abstract] ABSTRACT: In this letter we present the results of the search for massive magnetic monopoles in the penetrating cosmic ray radiation using the various subdetectors of the MACRO apparatus, during the period 1989–1995. Flux limits are given for the range 4 × 10−5 < β < 1; for 10−4 < β < 10−1 the limits are below the Parker bound, ∼ 10−15 cm−2s−1sr−1.
Full-text · Article · Aug 1997 · Physics Letters B
[Show abstract][Hide abstract] ABSTRACT: In this letter we present the results of the search for massive magnetic monopoles in the penetrating cosmic ray radiation using the various subdetectors of the MACRO apparatus, during the period 1989-1995. Flux limits are given for the β = v/c range 4 × 10-5 < β < 1; for 10-4 < β < 10-1 the limits are below the Parker bound, ∼ 10-15 cm-2s-1sr-1.
[Show abstract][Hide abstract] ABSTRACT: Using 5.33 × 106 single muons collected in 1.46 × 104 live hours by MACRO during the period 1991–1994, we have searched for a correlation between variations in the underground muon rate, Nμ, and seasonal temperature variations in the atmosphere. These correlations are found to be present with high statistical significance. Analysis of the relatively complete December 1992–December 1994 subset of the data yields a value for the temperature coefficient, . Analysis of the total data set gives consistent results.We have compared this result with the hypothesis that the muons observed in MACRO come from pion decays alone. Although our result is consistent with the ‘pion only’ hypothesis, a discussion of the sensitivity of our data sample to the kaon component of the cascades leading to observed muons underground will also be presented.
Full-text · Article · Jun 1997 · Astroparticle Physics
[Show abstract][Hide abstract] ABSTRACT: MACRO is designed to make a multiply redundant search for GUT magnetic monopoles over a wide velocity range. The 100 MHz pulse height recorder and synchronous encoder (PHRASE) and the energy reconstruction processor (ERP) are two components of that search, both based on the MACRO liquid scintillator. They are sensitive to monopoles with or without captured nuclei in the range β ∼ 10−3 to β ∼ 1. Here, the performance of these systems is discussed, including also analysis methods and background evaluations.
Full-text · Article · Feb 1997 · Astroparticle Physics
[Show abstract][Hide abstract] ABSTRACT: A study of the primary cosmic ray composition in the energy range 5ṡ1014−5ṡ1015 eV is performed through the analysis of the deep underground muons and of the e.m. component of Extensive Air Showers detected in coincidence by the MACRO and EAS-TOP experiments at the Gran Sasso Laboratory. We conclude that: a) pure proton and Iron primary beams are excluded by the experimental data; b) a fraction of nuclei heavier than Helium is necessary to explain the experimental data both below and above the knee; c) a mixed composition, obtained a priori from extrapolations of the spectra directly measured below 100 TeV, yields a reasonable account of the observations up to the knee of the primary spectrum.
Full-text · Article · Oct 1994 · Physics Letters B
[Show abstract][Hide abstract] ABSTRACT: We report on the simultaneous observation of atmospheric Čerenkov light by a prototype five telescope array, GRACE, (Gran Sasso Air Čerenkov Experiment) with deep underground muons in the MACRO (Monopole Astrophysics and Cosmic Ray Observatory). The telescope array was deployed at Campo Imperatore above the Gran Sasso Laboratory for a run completed in the fall of 1992. The total live time for the combined surface-underground operation was ∼100 h during which more than 300 events were seen in coincidence. The efficacy of this technique to monitor the electromagnetic and penetrating muon components of a cosmic-ray-induced cascade is discussed.
Full-text · Article · Oct 1994 · Physical Review D
[Show abstract][Hide abstract] ABSTRACT: Muon events collected with the streamer tube system of MACRO have been used to study the vertical muon intensity and to search for astrophysical point sources. New upper limits on the muon fluxes coming from source candidates have been obtained. The μ pair distance distribution and multimuon rates are presented and compared with Monte Carlo predictions for different primary cosmic rays composition models.
No preview · Article · May 1994 · Nuclear Physics B - Proceedings Supplements
[Show abstract][Hide abstract] ABSTRACT: An analysis of the coincident deep underground muon data and of the e.m. component of Extensive Air Showers (EAS) as measured by the MACRO and EAS-TOP experiments at Gran Sasso is presented. Constraints on the primary cosmic ray composition are obtained, with the use of an interaction model that is based on collider data. The possibility of extrapolating the directly measured energy spectra to our energy range is tested.
No preview · Article · May 1994 · Nuclear Physics B
[Show abstract][Hide abstract] ABSTRACT: A search for slowly moving magnetic monopoles in the cosmic radiation was conducted from October 1989 to November 1991 using the large liquid scintillator detector subsystem of the first supermodule of the MACRO detector at the Gran Sasso underground laboratory. The absence of candidates established an upper limit on the monopole flux of 5.6[times]10[sup [minus]15] cm[sup [minus]2] sr[sup [minus]1] s[sup [minus]1] at 90% confidence level in the velocity range of 10[sup [minus]4][approx lt][beta][lt]4[times]10[sup [minus]3]. This result places a new constraint on the abundance of monopoles trapped in our solar system.
No preview · Article · Feb 1994 · Physical Review Letters
[Show abstract][Hide abstract] ABSTRACT: We have analyzed a sample of 1.8 x 10 exp 6 muons with E(mu) greater
than about 1.3 TeV collected by the first and second supermodules of the
MACRO detector at Gran Sasso during the period 1989 February to 1991
February. We have searched for an excess of muons of celestial origin
over cosmic-ray background. Our search for steady sources in solid angle
bins of 3.0 x 3.0 deg in the declination range -5 to 90 deg was
negative; the upper limit with 95 percent C.L. to the muon flux at
midlatitudes is less than about 2 x 10 exp -12/sq cm s. In addition, we
have searched for muon excesses modulated by the orbital period of
selected X-ray sources, including Cyg X-3, Cyg X-1, Her X-1, 4U 0115 +
63, and 4U 1907 + 09. We have no evidence of any bursting activity from
Cyg X-3, during our search period, which includes the radio outburst of
Full-text · Article · Jun 1993 · The Astrophysical Journal