arXiv subjects

S. I. Klimushin

Publications and source records attributed to S. I. Klimushin.

9 recordsLinked to original sources

arXiv2002

Possibility of parametrization of atmospheric muon angular flux using underwater data

We present the formula for angular distribution of integral flux of conventional ($π, K$) muons deep under water taking into account the sphericity of the atmosphere and fluctuations of muon energy losses.The accuracy of this formula for various sea level muon spectra is discussed. The possibility of reconstructing two parameters of sea level spectrum by fitting measured underwater angular intensity is shown for Baikal Neutrino Telescope NT--36 experimental data.

hep-ph↗

arXiv2002

Accuracy of muon transport simulation

Chain of calculations which have to be performed to predict any kind of signal in a deep underwater/ice neutrino detector necessarily includes the lepton propagation through thick layers of matter, as neutrino can be observed only by means of leptons (muons, first of all, due to their large ranges) that are generated in $νN \to l N$ interactions. Thus, the muon propagation plays a key role when analyzing data and it is important to understand clearly how transportation part of simulation chain contributes to total inaccuracy of final results. Here we consider sources of uncertainties that appear in Monte Carlo algorithms for simulation of muon transport. The trivial but effective test is proposed to measure the propagation algorithm accuracy. The test is applied to three MC muon transport codes (PROPMU, MUSIC, MUM) and results are reported.

hep-ph↗

arXiv2001

MUM: flexible precise Monte Carlo algorithm for muon propagation through thick layers of matter

We present a new Monte Carlo muon propagation algorithm MUM (MUons+Medium) which possesses some advantages over analogous algorithms presently in use. The most important features of algorithm are described. Results on the test for accuracy of treatment the muon energy loss with MUM are presented and analyzed. It is evaluated to be of 0.002 or better, depending upon simulation parameters. Contributions of different simplifications which are applied at Monte Carlo muon transportation to the resulting error are considered and ranked. It is shown that when simulating muon propagation through medium it is quite enough to account only for fluctuations in radiative energy loss with fraction of energy lost being as large as 0.05 -- 0.1. Selected results obtained with MUM are given and compared with ones from other algorithms.

hep-ph↗

arXiv2001

Analytical description of muon distributions at large depths

The analytical expression for integral energy spectra and zenith angle distributions of atmospheric muons at large depths is derived. Fluctuations of muon energy losses are described using the parametrized correction factor. The fitting formula for the sea level muon spectrum at different zenith angles for spherical atmosphere is proposed. The concrete calculations for pure water are presented.

hep-ph↗

arXiv2001

Precise parametrizations of muon energy losses in water

The description of muon propagation through large depths of matter, based on a concept of the correction factor, is proposed. The results of Monte-Carlo calculations of this correction factor are presented. The parametrizations for continuous energy loss coefficients, valid in the broad interval of muon energies, and for the correction factor are given. The concrete calculations for pure water are presented.

hep-ph↗

arXiv2001

MUM: flexible precise algorithm for the muon propagation

We present a new muon propagation Monte Carlo FORTRAN code MUM (MUons+Medium) which possesses some advantages over analogous codes presently in use. The most important features of the algorithm are described. Data on the test for algorithm accuracy are presented. Contributions of different sources to the resulting error of simulation are considered. Selected results obtained with MUM are given and compared with ones from other codes.

hep-ph↗

arXiv2001

On the parametrization of atmospheric muon angular flux underwater

The analytical expression for angular integral flux of atmospheric muons in matter with the explicit relation of its parameters with those of the sea level spectrum is obtained. The fitting formula for the sea level muon spectrum at different zenith angles for spherical atmosphere is proposed. The concrete calculations for pure water are presented. Fluctuations of muon energy losses are taken into account by means of parametrized correction factor calculated using survival probabilities resulted from Monte Carlo simulations. Parametrizations of all continuous energy losses are obtained with using the most recent expressions for muon interaction cross-sections. The corresponding parametrization errors and field of method application are comprehensively discussed. The proposed formulae could be useful primarily for experimentalists processing data of arrays located deep under water or under ice.

hep-ph↗

arXiv2000

Simulation accuracy of long range muon propagation in medium: analysis of error sources

Knowledge of atmospheric muon flux intensity at large depths is extremely important for neutrino telescopes located deep under ground, water or ice. One of the methods to transform muon sea-level spectrum into depth one is to apply Monte Carlo technique which directly takes into account stochastical nature of energy loss. In order to decrease computation time down to acceptable level one has to use simplifications resulting in systematic errors which in some cases may distort result essentially. Here in this paper we present our analysis for dependence of computed depth muon flux upon the most important parameters of muon transport Monte Carlo algorithm which was done with the MUM (MUons+Medium) code. Contribution of different simplifications to the resulting error is considered, ranked and compared with uncertainties which come from parametrization accuracy both for sea-level muon spectrum and for muon cross sections.

hep-ph↗

arXiv1998

The Experimental Limits on Q-ball Flux with the Baikal Deep Underwater Array "Gyrlyanda"

Supersymmetric models allow for stable non-topological solitons, Q-balls, which can be produced in the early Universe and contribute to dark matter. Experimental signature of electrically neutral Q-balls is, in fact, the same as is expected for superheavy magnetic monopoles catalyzing baryon decay. Here we use the upper limits on monopole flux obtained with deep underwater Cherenkov array "Gyrlyanda" which operated in the Baikal lake in 1984-90 with 267 days of live time to obtain the limit on Q-ball flux. The last has been found to be equal to 3.9 x 10^{-16} cm^{-2} sr^{-1} s^{-1} (90% CL). This result is discussed and compared with other restrictions.

astro-ph↗