7,101 research outputs found

    High transverse momentum inclusive neutral pion production in d+Au collisions at RHIC

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    Preliminary results are presented on high-pT inclusive neutral pion production in d+Au collisions at sqrt(sNN) = 200 GeV in the pseudo-rapidity range 0 gamma,gamma are detected in the Barrel electromagnetic calorimeter of the STAR experiment at RHIC. The analysis procedure is described in detail and the results are found to be in good agreement with earlier STAR findings and with next-to-leading order perturbative QCD calculations.Comment: 4 pages, 3 figures, poster proceedings of Quark Matter conference, Budapest (Hungary), 4-9 August 200

    Analysis of migration processes based on census data

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    The subject matter of research is the internal migration processes of the Russian population in the period from the 1960s to 2010. The research is based on the data about the territorial population flows published in the all-Union census materials of 1970, 1979, and 1989, and in the all-Russia census materials of 2002 and 2010. The basic migration flows and directions are considered. Methodologically, the analysis of migration is based on the use of end-to-end indicators enabling to assess the dynamics of migration processes over a long period. Special attention is paid to rural-urban internal migrations, the volumes, patterns and consequences of which have not been so far properly investigated or assessed. The authors offer and calculate relative indicators that have never been used to assess the processes in question. To make the census materials of the soviet and post-soviet periods comparable, the economic zoning adopted before 2000 is used, and the administrative-territorial network is unified. The authors confirm the hypothesis that from decade to decade the intensity of territorial mobility of both urban and rural population was reduced. Interregional migration flows are considered, and various tendencies and migration intensity for over four decades are de ned. The authors analyze the dynamics in the structure of migrants by the time they lived in the place of their permanent residence in various regions. The research shows that the tendencies developed at that time and persisting continue to adversely affect the territorial re-distribution of population and the regional social and economic development of the country. The research results can be used in adjusting the regional socio-economic and migration policy.The article has been prepared with the support of the Russian Humanitarian Science Foundation Project № 14–02–00525

    First results from the TUS orbital detector in the extensive air shower mode

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    TUS (Tracking Ultraviolet Set-up), the first orbital detector of extreme energy cosmic rays (EECRs), those with energies above 50 EeV, was launched into orbit on April 28, 2016, as a part of the Lomonosov satellite scientific payload. The main aim of the mission is to test a technique of registering fluorescent and Cherenkov radiation of extensive air showers generated by EECRs in the atmosphere with a space telescope. We present preliminary results of its operation in a mode dedicated to registering extensive air showers in the period from August 16, 2016, to November 4, 2016. No EECRs have been conclusively identified in the data yet, but the diversity of ultraviolet emission in the atmosphere was found to be unexpectedly rich. We discuss typical examples of data obtained with TUS and their possible origin. The data is important for obtaining more accurate estimates of the nocturnal ultraviolet glow of the atmosphere, necessary for successful development of more advanced orbital EECR detectors including those of the KLYPVE (K-EUSO) and JEM-EUSO missions.Comment: 18 pages; v2: references fixed; v3: minor changes to address referee's comment

    Measurement of air fluorescence light yield induced by an electromagnetic shower

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    For most of the Ultra High Energy Cosmic Ray (UHECR) experiments and projects (HiRes, AUGER, TA, JEM-EUSO, TUS,...), the detection technique of Extensive Air Showers (EAS) is based, at least, on the measurement of the air fluorescence induced signal. The knowledge of the Fluorescence Light Yield (FLY) is of paramount importance for the UHECR energy reconstruction. The MACFLY experiment was designed to perform such FLY measurements. In this paper we will present the results of dry air FLY induced by 50 GeV electromagnetic showers as a function of shower age and as a function of the pressure. The experiment was performed at CERN using an SPS electron test beam line. It is shown that the FLY is proportional to deposited energy in air (E_d) and that the ratio FLY/E_d and its pressure dependence remain constant independently of shower age and more generally independently of the excitation source used (single electron track or air shower).For most of the Ultra High Energy Cosmic Ray (UHECR) experiments and projects (HiRes, AUGER, TA, JEM-EUSO, TUS,...), the detection technique of Extensive Air Showers (EAS) is based, at least, on the measurement of the air fluorescence induced signal. The knowledge of the Fluorescence Light Yield (FLY) is of paramount importance for the UHECR energy reconstruction. The MACFLY experiment was designed to perform such FLY measurements. In this paper we will present the results of dry air FLY induced by 50 GeV electromagnetic showers as a function of shower age and as a function of the pressure. The experiment was performed at CERN using an SPS electron test beam line. It is shown that the FLY is proportional to deposited energy in air (E_d) and that the ratio FLY/E_d and its pressure dependence remain constant independently of shower age and more generally independently of the excitation source used (single electron track or air shower)

    Measurement of air and nitrogen fluorescence light yields induced by electron beam for UHECR experiments

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    Most of the Ultra High Energy Cosmic Ray (UHECR) experiments and projects (HiRes, AUGER, TA, EUSO, TUS,...) use air fluorescence to detect and measure extensive air showers (EAS). The precise knowledge of the Fluorescence Light Yield (FLY) is of paramount importance for the reconstruction of UHECR. The MACFLY - Measurement of Air Cherenkov and Fluorescence Light Yield - experiment has been designed to perform such FLY measurements. In this paper we will present the results of FLY in the 290-440 nm wavelength range for dry air and pure nitrogen, both excited by electrons with energy of 1.5 MeV, 20 GeV and 50 GeV. The experiment uses a 90Sr radioactive source for low energy measurement and a CERN SPS electron beam for high energy. We find that the FLY is proportional to the deposited energy (E_d) in the gas and we show that the air fluorescence properties remain constant independently of the electron energy. At the reference point: atmospheric dry air at 1013 hPa and 23C, the ratio FLY/E_d=17.6 photon/MeV with a systematic error of 13.2%.Comment: 19 pages, 8 figures. Accepted for publication in Astroparticle Physic
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