A scheme for modeling tracks of recoil nuclei from elastic scattering of hypothetical dark-matter weakly interacting massive particles (WIMPs) is presented. Constraints on the possibility of ...directional detection of WIMPs in experiments where light hydrogen nuclei and groups of C, N, and O nuclei, as well as fluorine nuclei, play the role of a target in the detector used are set. The number of WIMPs interactions per unit mass of the detector was estimated by means of the micrOMEGAs software package for an inert doublet model. It is concluded that, for the purpose of visualizing tracks of recoil nuclei and, accordingly, accomplishing a directional detection of WIMPs with lowest assumed masses of 4 to 10 GeV, preference should be given to target of lower density.
Here we present the current state of the technical design of the SPHERE project’s new detector. The SPHERE project is aimed at primary cosmic ray studies in the 1–1000 PeV energy range using the ...reflected Cherenkov light method. The concept of a drone mounted detector with a photosensitive camera based on silicon photomultipliers is discussed. The design details of a small scale prototype of this detector is presented.
The recent results of the very precise measurements of the primary cosmic protons and helium nuclei energy spectra by AMS-02 and some rather accurate estimates of these energy spectra generated in ...SNR allow us to elaborate the new approximation of the pimary nucleon energy spectra. As the acuracy of this approximation is rather high we can use it to test various models of hadronic interactions with the help of atmospheric muon energy spectra. The atmospheric vertical muon energy spectra have been calcullated in terms of the EPOS LHC, QGSJET01, QGSJETII-03 and QGSJETII-04 models in the energy range 102 ÷ 105 GeV with help of the CORSIKA package and this new approximation of the primary nucleon spectrum. The comparison of calculations with the muon spectra observed by collaborations L3+Cosmic, LVD and MACRO has shown that all models predict approximately two times lower intensity of the muon energy spectra. As these muons are products of decays of the most energetic π± and K± mesons in the atmosphere, we can conclude that production of these π± and K± mesons is underestimated by EPOS LHC, QGSJET01, QGSJETII-03 and QGSJETII-04 models.
A determination of the composition of primary cosmic rays in the energy range between 1 and 1000 PeV is an important objective in studies of processes involving the formation and propagation of ...cosmic rays. On the basis of experience gained in exploiting the SPHERE-2 balloon-based facility, a SPHERE-3 facility, which possesses a wider aperture and a better optical resolution, is developed. The current status of work on designing this facility is presented.
Paper contains the first results on the development of a SPHERE-3 telescope for the primary cosmic ray studies in 1–1000 PeV energy range using reflected and direct Cherenkov light generated by ...extensive air showers. It also sheds some light on the development of our new approach to the design of the new telescope.
Further development of the way of studying primary cosmic rays by detecting the reflected extensive air shower Cherenkov light is planned, based on the successful implementation of the SPHERE-2 ...aerostat experiment. The possibility of simultaneously detecting direct and reflected Cherenkov light from extensive air showers is demonstrated. Prospects for creating a new SPHERE-3 detector are discussed and the first results from modeling are presented.
The imaging method based on the absorption and scattering of atmospheric muons (muography method) uses the natural flow of muons formed in the interactions of cosmic rays in the atmosphere. The ...method is at the junction of elementary particle physics and research in other very diverse fields of natural science, in particular, in archaeology. The paper presents the first results of an experiment to study a unique underground structure in the Holy Dormition Pskov-Caves Monastery, which is a cultural object with a centuries-old history.
Fluctuations of lateral distributions of signals in the surface scintillation detectors of the Yakutsk array are found to be large. New estimates of the inclined shower energy had been suggested. In ...view of these estimates the Yakutsk energy spectrum becomes quite comparable with the spectra observed at the Pierre Auger Observatory and the Telescope Array. The shower energy calculated using the data of only one detector may be overestimated if fluctuations are neglected.
Direct Dark Matter searches are nowadays one of the most fervid research topics with many experimental efforts devoted to the search for nuclear recoils induced by the scattering of Weakly ...Interactive Massive Particles (WIMPs). Detectors able to reconstruct the direction of the nucleus recoiling against the scattering WIMP are opening a new frontier to possibly extend Dark Matter searches beyond the neutrino background. Exploiting directionality would also prove the galactic origin of Dark Matter with an unambiguous signal-to-background separation. Indeed, the angular distribution of recoiled nuclei is centered around the direction of the Cygnus constellation, while the background distribution is expected to be isotropic. Current directional experiments are based on gas TPC whose sensitivity is limited by the small achievable detector mass. In this paper we present the discovery potential of a directional experiment based on the use of a solid target made of newly developed nuclear emulsions and of optical read-out systems reaching unprecedented nanometric resolution.
The study of cosmic rays mass composition is an important problem in high-energy physics. The main goal of the SPHERE-2 experiment was to study the energy spectrum of the primary cosmic rays in the ...10–300 PeV energy range. Also the experimental data allow approaching their mass composition. The separation of events into nuclei groups makes it possible to estimate the average masses over the sample. Using machine learning methods, we developed a separation method for the primary nuclei groups that formed extensive air showers based on the simulated events for the SPHERE-2 telescope. Various models of the high energy nucleus-nucleus interaction were used, but their predictions differ significantly. In the SPHERE-2 experiment data analysis, this problem was solved, first, by the use of the data on Cherenkov light, which has weak dependence on the model of hadronic interaction; second, the neural network was trained simultaneously on two interaction models (QGSJET-01 and QGSJETII-04), which differ greatly from each other. Therefore, the independence of experimental data processing from the choice of the nuclear interaction model was ensured. The regression task is solved by machine learning methods. The separation of events into three groups of nuclei—protons (p), nitrogen (N), and iron (Fe)—by using a neural network is more precise than that by using traditional methods.
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