451 research outputs found

    Опыт и возможности применения космических систем дистанционного зондирования Земли для прогнозирования золоторудного оруденения на труднодоступных территориях на примере Полярного Урала

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    The questions of the using of domestic and foreign spacecraft (SC), as well as Earth remote sensing (ERS) equipment for search and predication of gold mineralization on the example of the promising and difficult to approach areas of the Polar and the Northern Urals are discussed in the article. The solution of this problem is showed on the example of the prospective areas of the Arctic and the Northern Urals based on analysis of Landsat 7 multispectral images. Hidden structures (arc, annular, and radial) were detected with help of analyses of Landsat 7 imagery. Hidden structures determine the position of gold mineralization of the Toupugol-Hanmeyshorskogo (the Novogodnenskoe ore field, the Polar Urals) and the Turinsko-Auerbahovskogo (the Auerbachovskoe ore field, the Northern Urals) ore regions. The decision of this problem is given on the example of the promising territory of the Polar Urals with the use foreign SC the Landsat 7. Comparative analysis of the existing SC of ERS has been carried out, this target information has in the public domain. The onboard equipment installed on domestic spacecraft and the information obtained with use onboard equipment meets the existing requirements. These requirements are placed to onboard equipment to solve the problem of search and predication mineralization. At the same time, the capabilities of the deployed domestic orbital grouping of SC of ERS transcend the capabilities of SC of ERS the Landsat 7. Opportunity of obtaining geospatial information with the use of pseudospacecrafts is being considered. These have several advantages over SC and unmanned aerial vehicles.В представленной статье рассматриваются вопросы применения отечественных и иностранных космических аппаратов (КА), а также их аппаратуры дистанционного зондирования Земли (ДЗЗ) для поиска и прогнозирования золоторудного оруденения на труднодоступных территориях. Приведен пример решения этой задачи на перспективных территориях Полярного и Северного Урала. По материалам многозональной космической съемки аппаратом Landsat 7 выявлены крупные кольцевые, дуговые и радиальные структуры, определяющие позицию золоторудного оруденения Тоупугол-Ханмейшорского (Новогодненское рудное поле, Полярный Урал) и Турьинско-Ауэрбаховского (Ауэрбаховское рудное поле, Северный Урал) рудных районов. Проведен сравнительный анализ существующих КА ДЗЗ, целевая информация о которых имеется в открытом доступе. Показано, что бортовая аппаратура, установленная на отечественных КА, и получаемая с ее помощью информация отвечают существующим требованиям, предъявляемым к ним для решения задачи поиска и прогнозирования оруденения. При этом возможности развернутой отечественной орбитальной группировки КА ДЗЗ превосходят возможности КА ДЗЗ Landsat 7. Рассматривается возможность получения геопространственной информации с использованием нового вида летательных аппаратов - псевдокосмических аппаратов (ПКА), обладающих рядом преимуществ как перед КА, так и перед беспилотными летательными аппаратами (БПЛА)

    The “Horizon-T” Experiment: Extensive Air Showers Detection

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    Horizon - T is a n innovative detector system constructed to study Extensive Air Showers (EAS) in the energy range above 10 16 eV coming from a wide range of zenith angles (0 o - 85 o ). The system is located at Tien Shan high - altitude Science Station of Lebedev Physical Institute of the Russian Academy of Sciences at approximately 3340 meters above the sea level. It consists of eight charged particle detection points separated by the distance up to one kilometer as well as optical detector subsystem to view the Vavilov - Cherenkov light from the EAS. The time resolution of charged particles and Vavilov - Cherenkov light photons passage of the detector system is a few ns. This level of resolution allows conducting research of atmos pheric development of individual EAS

    Isovector soft dipole mode in 6Be

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    By using the 1H(6Li,6Be)n charge-exchange reaction, continuum states in 6Be were populated up to E_t=16 MeV, E_t being the 6Be energy above its three-body decay threshold. In kinematically complete measurements performed by detecting alpha+p+p coincidences, an E_t spectrum of high statistics was obtained, containing approximately ~5x10^6 events. The spectrum provides detailed correlation information about the well-known 0^+ ground state of 6Be at E_t=1.37 MeV and its 2^+ state at E_t=3.05 MeV. Moreover, a broad structure extending from 4 to 16 MeV was observed. It contains negative parity states populated by Delta L=1 angular momentum transfer without other significant contributions. This structure can be interpreted as a novel phenomenon, i.e. the isovector soft dipole mode associated with the 6Li ground state. The population of this mode in the charge-exchange reaction is a dominant phenomenon for this reaction, being responsible for about 60% of the cross section obtained in the measured energy range.Comment: 8 pages, 7 figure

    Search for H→γγ produced in association with top quarks and constraints on the Yukawa coupling between the top quark and the Higgs boson using data taken at 7 TeV and 8 TeV with the ATLAS detector

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    A search is performed for Higgs bosons produced in association with top quarks using the diphoton decay mode of the Higgs boson. Selection requirements are optimized separately for leptonic and fully hadronic final states from the top quark decays. The dataset used corresponds to an integrated luminosity of 4.5 fb−14.5 fb−1 of proton–proton collisions at a center-of-mass energy of 7 TeV and 20.3 fb−1 at 8 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. No significant excess over the background prediction is observed and upper limits are set on the tt¯H production cross section. The observed exclusion upper limit at 95% confidence level is 6.7 times the predicted Standard Model cross section value. In addition, limits are set on the strength of the Yukawa coupling between the top quark and the Higgs boson, taking into account the dependence of the tt¯H and tH cross sections as well as the H→γγ branching fraction on the Yukawa coupling. Lower and upper limits at 95% confidence level are set at −1.3 and +8.0 times the Yukawa coupling strength in the Standard Model

    Search for vectorlike B quarks in events with one isolated lepton, missing transverse momentum, and jets at √s = 8 TeV with the ATLAS detector

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    A search has been performed for pair production of heavy vectorlike down-type (B) quarks. The analysis explores the lepton-plus-jets final state, characterized by events with one isolated charged lepton (electron or muon), significant missing transverse momentum, and multiple jets. One or more jets are required to be tagged as arising from b quarks, and at least one pair of jets must be tagged as arising from the hadronic decay of an electroweak boson. The analysis uses the full data sample of pp collisions recorded in 2012 by the ATLAS detector at the LHC, operating at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3 fb −1 . No significant excess of events is observed above the expected background. Limits are set on vectorlike B production, as a function of the B branching ratios, assuming the allowable decay modes are B → Wt/Zb/Hb. In the chiral limit with a branching ratio of 100% for the decay B → Wt, the observed (expected) 95% C.L. lower limit on the vectorlike B mass is 810 GeV (760 GeV). In the case where the vectorlike B quark has branching ratio values corresponding to those of an SU(2) singlet state, the observed (expected) 95% C.L. lower limit on the vectorlike B mass is 640 GeV (505 GeV). The same analysis, when used to investigate pair production of a colored, charge 5/3 exotic fermion T 5/3 , with subsequent decay T 5/3 → Wt, sets an observed (expected) 95% C.L. lower limit on the T 5/3 mass of 840 GeV (780 GeV)

    Fiducial and differential cross sections of Higgs boson production measured in the four-lepton decay channel in pp collisions at √s = 8 TeV with the ATLAS detector

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    Measurements of fiducial and differential cross sections of Higgs boson production in the H→ZZ∗ → 4ℓ decay channel are presented. The cross sections are determined within a fiducial phase space and corrected for detection efficiency and resolution effects. They are based on 20.3 fb−¹ of pp collision data, produced at √s = 8 TeV centre-of-mass energy at the LHC and recorded by the ATLAS detector. The differential measurements are performed in bins of transverse momentum and rapidity of the four-lepton system, the invariant mass of the subleading lepton pair and the decay angle of the leading lepton pair with respect to the beam line in the four-lepton rest frame, as well as the number of jets and the transverse momentum of the leading jet. The measured cross sections are compared to selected theoretical calculations of the Standard Model expectations. No significant deviation from any of the tested predictions is found
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