Studies of a three-stage dark matter and neutrino observatory based on multi-ton combinations of liquid xenon and liquid argon detectors

We study a three stage dark matter and neutrino observatory based on multi-ton two-phase liquid Xe and Ar detectors with sufficiently low backgrounds to be sensitive to WIMP dark matter interaction cross sections down to 10E-47 cm^2, and to provide both identification and two independent measurements of the WIMP mass through the use of the two target elements in a 5:1 mass ratio, giving an expected similarity of event numbers. The same detection systems will also allow measurement of the pp solar neutrino spectrum, the neutrino flux and temperature from a Galactic supernova, and neutrinoless double beta decay of 136Xe to the lifetime level of 10E27 - 10E28 y corresponding to the Majorana mass predicted from current neutrino oscillation data. The proposed scheme would be operated in three stages G2, G3, G4, beginning with fiducial masses 1-ton Xe + 5-ton Ar (G2), progressing to 10-ton Xe + 50-ton Ar (G3) then, dependent on results and performance of the latter, expandable to 100-ton Xe + 500-ton Ar (G4). This method of scale-up offers the advantage of utilizing the Ar vessel and ancillary systems of one stage for the Xe detector of the succeeding stage, requiring only one new detector vessel at each stage. Simulations show the feasibility of reducing or rejecting all external and internal background levels to a level <1 events per year for each succeeding mass level, by utilizing an increasing outer thickness of target material as self-shielding. The system would, with increasing mass scale, become increasingly sensitive to annual signal modulation, the agreement of Xe and Ar results confirming the Galactic origin of the signal. Dark matter sensitivities for spin-dependent and inelastic interactions are also included, and we conclude with a discussion of possible further gains from the use of Xe/Ar mixtures

Ocena efektywności interwencji rynkowych Europejskiego Banku Centralnego w latach 2010–2016

The article is aimed at the analysis of the impact of the post-crisis interventions made by the European Central Bank in the years 2010–2016. The analysis refers to the aid programmes actually implemented in favour of banks and governments of the indebted EU countries as well as the information policy concerning the programmes announced but not implemented so far. On the basis of the quotation of domestic credit risk swaps (CDS) and the credit action dynamics the impact of the analysed aid programmes on the real sphere of the economy was assessed. The observations indicate that interventions were effective as after they were introduced, the events that the Bank wanted to prevent did not take place. At the same time, no negative effects of the discussed programmes were explicitly confirmed. A relatively high effectiveness of the information policy of Central Bank was observed in comparison with expensive intervention programmes. Thus, it was found that the EBC activities within the discussed scope brought the intended effects and may be regarded effective.Celem artykułu jest analiza skutków pokryzysowych interwencji prowadzonych przez Europejski Bank Centralny w latach 2010–2016. Analizie poddano zarówno faktycznie wprowadzone w życie programy pomocowe dla banków oraz rządów zadłużonych państw UE, jak i politykę informacyjną, dotyczącą programów jedynie ogłoszonych, do których realizacji dotychczas nie doszło. Na podstawie badania notowania krajowych swapów ryzyka kredytowego (CDS) oraz dynamiki akcji kredytowej oszacowano wpływ omawianych programów pomocowych na strefę realną gospodarki. Dokonane obserwacje wskazują na to, że interwencje EBC były skuteczne w tym sensie, że po ich przeprowadzeniu nie wystąpiły zdarzenia, którym bank centralny chciał zapobiec. Jednocześnie nie stwierdzono wywołania jednoznacznie negatywnych skutków omawianych programów. Zaobserwowano także względnie wysoką – wobec drogich programów interwencyjnych – efektywność polityki informacyjnej banku centralnego. Tym samym stwierdzono, że prowadzone w omawianym okresie działania EBC przyniosły zamierzone efekty i mogą zostać uznane za skuteczne