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1.
Using data from inclined events ( 60 degrees 相似文献   

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We argue that the data published by the Pierre Auger Collaboration [1] disfavors, at the 99% confidence level, their hypothesis that most of the highest-energy cosmic rays are protons from nearby astrophysical sources—either active galactic nuclei or other objects with a similar spatial distribution. The text was submitted by the authors in English.  相似文献   

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We have measured absolute fluxes of primary protons, helium nuclei and atmospheric muons with the BESS spectrometer. Precise measurement of these cosmic-ray particles is indispensable for improving the accuracy in the atmospheric neutrino calculations.  相似文献   

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Kinematics predicts the severe suppression of low-energy (<1 GeV) secondary antiprotons in the Galactic cosmic rays. Thus the observation several years ago of a finite flux of low-energy antiprotons could not be explained with existing models of cosmic ray propagation, which led to a plethora of theoretical speculation. We have recently flown a balloon-borne instrument to measure the energy spectrum of cosmic-ray , and have found no antiprotons in the energy interval 200–640 MeV (corrected to the top of the atmosphere). This yields an upper limit to the ratio of 5.5×10−5 (90% confidence level), well below and hence contradicting the earlier result.  相似文献   

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This paper reports on the results of measurements performed in the course of the ATIC-2 balloon experiment (2002–2003) for the energy spectra of particles (such as protons; He, C, O, Ne, Mg, Si, and Fe nuclei; and some groups of nuclei) and the all-particle energy spectrum in primary cosmic rays at energies ranging from 50 GeV to 200 TeV. The conclusion is drawn that the energy spectra of protons and helium nuclei differ substantially (the spectrum of protons is steeper) and that the shape of the energy spectra of protons and heavy nuclei cannot be described by a power function.  相似文献   

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We discuss the possibility of predicting dangerous radiation fluxes of solar cosmic rays (SCRs) with energies of tens to hundreds of MeV on the basis of data from neutron monitors located on the Earth’s surface. Neutron monitors record relativistic cosmic rays (energies of 0.5 to several GeV) with minimal delay, but the intensity of cosmic rays is low in the high-energy region and does not pose a serious radiation hazard. By determining the spectrum of cosmic rays at high energies, however, it is possible to forecast radiation dangerous particle fluxes of moderate energies with a lead time of several hours. Such forecasts are, however, possible only with data on the so-called delay component of relativistic cosmic rays.  相似文献   

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The results of analysis of arrival frequency of cosmic rays with energies E 0≥4×1017 eV are presented based on the data collected on the Yakutsk array during its 24 years of continuous operation (1977–2000). It is shown that the intensity of cosmic rays is variable. At E 0≤(3?5)×1018 eV, the (2–3)-month data show many deviations by (3–4)σ from the mean level. At E 0≥1019 eV, the intensities steadily decrease, on the average, by 1.5 times during the time period considered.  相似文献   

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Summary We discuss here the results obtained calculating the contribution of prompt muons in the vertical atmospheric muon flux, computed taking into account the up-to-date data from experiments at accelerators and the most recent theoretical achievements on charm generation in nucleon-air nucleus interactions. Our results are compared with the experimental data obtained with underground detectors.
Riassunto Si discutono in questo lavoro i risultati ottenuti sul contributo di muoni pronti al flusso atmosferico verticale dei muoni, calcolato utilizzando i dati piú recenti di esperimenti degli acceleratori ed i risultati teorici sulla produzione di particelle charmate in interazioni nucleoni-nuclei atmosferici. I risultati ottenuti sono confrontati con i dati sperimentali forniti da esperimenti sotterranei.

Резюме Мы обсуждаем результаты вычислений вклада мгновенных мюонов в вертикальный роток атмосферных мюонов. Вычисления учитывают данные из зкспериментов на ускорителях и недавние теоретические предсказания по рождению очарованных частиц при, взаимодействиях нуклонов с ядрами воздуха. Наши результаты сравниваются с зкспериментальными данными, полученными с помощью подземных детекторов.
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11.
Summary Energy spectra and zenith-angle distributions of cosmic-ray muons, neutrinos and antineutrinos of prompt generation for energy interval (1÷106) TeV are calculated. For calculations of differential cross-sections of D±, D0, 0 and Λc production inNN and πN interactions the recombination quark-parton model (RQPM) is used. Accounting of nuclear effects is done by using the additive quark model and the optical model of nucleus. Detailed comparison of results obtained in RQPM with corresponding predictions of quark-gluon string model (MQGS) is carried out. Dynamics of semi-leptonic D- and Λc and energy losses of muons in the atmosphere are taken into account. Calculations of hadronic cascades in the atmosphere are done with accounting of growth with energy of total inelastic hadron-nucleus cross-sections, steepening of primary cosmic-ray spectrum and processes of pion regeneration. The comparison of our calculations with experimental data and with calculations of other authors is given.  相似文献   

12.
The first clean Centauro was found in cosmic rays years many ago at Mt Chacaltaya experiment. Since that time, many people have tried to find this type of interaction, both in cosmic rays and at accelerators. But no one has found a clean cases of this type of interaction.It happened finally in the last exposure of emulsion at Mt Chacaltaya where the second clean Centauro has been found. The experimental data for both the Centauros and STRANA will be presented and discussed in this paper. We also present our comments to the intriguing question of the existence of a type of nuclear interactions at high energy with alignment.  相似文献   

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A rotating torsion balance method to detect the product of the photon mass squared and the ambient cosmic vector potential is proposed. This modulation method is efficacious whether the vector potential is fortuitously aligned with Earth's rotation axis or not, and the experimental precision of the modulation method can be improved by at least an order of magnitude compared to the statistical method.  相似文献   

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Detection of the organic substance on the Mars is one of the main targets of the current and future Martian landing missions. In this study, we calculated the ionization of the Martian soil by solar and Galactic cosmic rays at its various depths. It is shown that complex organic molecules (biomarkers) with a mass more than 300 a.m.u. at a depth of ≤10 cm degrade for a time less than one milliard years.  相似文献   

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Recent work on the energy spectrum, composition and anisotropy of the primary cosmic ray flux from about 109 eV to 1020 eV is summarized, together with related information on phonons between 1 MeV and 200 MeV. Solar particles are not discussed, the emphasis being on topics bearing on the origin of the radiation, which is still an unsolved problem, although the probabilities are strongly in favour of an entirely galactic origin for the particles. Mechanisms of acceleration are not discussed.  相似文献   

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