摘要:

Recent results on solar neutrinos and atmospheric neutrinos from Kamiokande are presented. The measured8B solar neutrino flux relative to a prediction based on the standard solar model was 0.49±0.05(stat)±0.06(syst). The data sample was tested for any correlation with sunspot numbers; within the statistical error, no significant effect was observed. The &mgr;‐like/e‐like ratio of atmospheric neutrino fluxes was measured. The ratio relative to a Monte Carlo prediction was 0.60±0.06(stat)±0.05(syst). The implications of these results for neutrino oscillations are discussed.

ISSN:0094-243X    

DOI:10.1063/1.43255

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

The results on the spin structure of the proton suggest the presence of an axial strangeness current interaction. This would modify the assumed transition strengths for the analysis of the solar neutrino experiments sensitive to neutral currents. In the long wavelength limit a deuterium target is insensitive to such a mechanism. In the planned BOREX experiment the isoscalar strength would increase the observed rate by 30–40%, associated mainly with the neutrino‐proton component.

ISSN:0094-243X    

DOI:10.1063/1.43256

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

Recent results from the CYGNUS cosmic‐ray experiment are presented, including a survey of the northern sky for continuous point sources and a search for emission lasting several hours (one day of observation) from many known x‐ray and &ggr;‐ray sources. The performance of five water‐C˘erenkov detectors recently added to the CYGNUS array is summarized. A proposed water‐C˘erenkov detector called MILAGRO for the detection of cosmic‐ray air showers over a broad energy range, 1–1000 TeV, is described.

ISSN:0094-243X    

DOI:10.1063/1.43257

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

The CASA‐MIA experiment is a very large extensive air shower detector with good angular resolution. This instrument has been used to search the entire visible sky for astrophysical point sources of 100 TeV gamma rays. Approximately 90% of the isotropic charged cosmic ray background is rejected by measuring the muon content of the showers. Stringent limits are placed on the possible flux of 100 TeV sources across a large part of the Northern sky.

ISSN:0094-243X    

DOI:10.1063/1.43258

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

The HEGRA collaboration has collected 225 million air shower events with a scintillator array distributed over 3.2×104m2in the time between 1989 and 1992. We have searched the data for steady state and sporadic emission from point sources. The median energy of &ggr; showers registers by our detector is about 75 TeV and the average angular resolution 0.7°. No significant steady state or sporadic excess has been found. Upper limits are presented.

ISSN:0094-243X    

DOI:10.1063/1.43259

出版商:AIP    

年代:1992

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.43260

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

The Thermistocle experiment, which consists of an array of 18 Cherenkov telescopes located on the French Pyrene´es, has successfully observed the emission of multi‐TeV gamma rays from the CRAB source, with a significance corresponding to 6.5 standard deviations. The source is resolved with an accuracy of 2.5 mr (&bartil;8 arc min.) per shower. The observation of the signal relies uniquely on the high angular resolution in determining the direction of the individual showers. The source is localized with the precision of the order of 0.5 mr (&bartil;2 arc min.) in an energy range so far unexplored. The energy of the gammas is estimated by measuring the amplitude of the Cherenkov signal detected by each of the 18 telescopes. The energy spectrum of the CRAB gamma source is determined in the range from 3 to 15 TeV. The results are compatible with a power extrapolation of the data available at lower energies (<1 TeV).

ISSN:0094-243X    

DOI:10.1063/1.43261

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

We present results from approximately 2 years running with the MACRO detector. Most of these data were taken with one of the six supermodules of the final detector in operation. Using a sample of 1.8×106muons with E≳1.4 TeV we have searched for an excess of muons of celestial origin over cosmic ray background. No evidence for steady point sources was found. The upper limit on the muon flux at 95% CL is typically 2×10−12cm−2 sec−2. No evidence for time modulated point sources was found. The muon multiplicity distribution favors a ‘‘light’’ composition for cosmic ray primaries with ≊75% protons above ∼103TeV. We have also searched for neutrino bursts from supernovae in our Galaxy. None were observed during the period Oct. 1989 to Feb. 1992. Our sensitivity to neutrino bursts from collapsing stars extends to ≊60% of the stars in the Galaxy.

ISSN:0094-243X    

DOI:10.1063/1.43557

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

A negative search using 1/12 of the eventual MACRO detector, has yielded strange quark matter flux limits of 1.1×10−14cm−2sr−2 s−1for 10−10g<m<0.1g, and 5.5×10−15cm−2sr−1 s−1for m≳0.1g. We have modified the formula of the De Ruju´la and Glashow for the light yield of strange quark matter to include the UV light absorbed and re‐emitted in the visible region, and proved that the MACRO sensitivity extends almost to the escape velocity of the earth. Our flux limit, therefore, not only applies to strange quark matter of galactic and extragalactic origin but can also be used to address strange quark matter possibly trapped in our solar system.

ISSN:0094-243X    

DOI:10.1063/1.43558

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

The Soudan 2 underground detector is a large fine‐grained tracking calorimeter comprised of long drift tubes read out by proportional wires. It is surrounded by a proportional tube shield. Preliminary nucleon decay results with 0.5 fiducial kT‐yr exposure give 90% CL lower limits of &tgr;/B≳4.5×1030yr for the modep→K+&ngr;. A search for GUT magnetic monopoles making highly ionizing tracks yielded a 90% CL upper flux limit of 8.7×10−15cm−2s−1sr−1for monopole velocities of &bgr;≳2×10−3in data taken over almost three years.

ISSN:0094-243X    

DOI:10.1063/1.43559

出版商:AIP    

年代:1992

数据来源: AIP