Limits on Dark Matter Effective Field Theory Parameters with CRESST-II

CRESST is a direct dark matter search experiment, aiming for an observation of nuclear recoils induced by the interaction of dark matter particles with cryogenic scintillating calcium tungstate crystals. Instead of confining ourselves to standard spin-independent and spin-dependent searches, we re-analyze data from CRESST-II using a more general effective field theory (EFT) framework. On many of the EFT coupling constants, improved exclusion limits in the low-mass region (< 3-4 GeV) are presented.Comment: 7 pages, 9 figure

On Geoneutrinos

Experimental data on geoneutrinos allow to admit that masses of U, Th and K in the Earth can be up to mU = 1.7 · 1017 kg, mTh = 6.7 · 1017 kg and mK/mEarth ~ 2%. These values correspond to intrinsic Earth heat flux in ~300 TW. The most part of this flux goes up in rift zones as a heated gases. Argo Project results and the measurements of the Moon intrinsic heat flux support the existence of such a big flux. So large of U, Th, K abundances were predicted by Adjusted Hydridic Earth model

On Geoneutrinos

Experimental data on geoneutrinos allow to admit that masses of U, Th and K in the Earth can be up to mU = 1.7 · 1017 kg, mTh = 6.7 · 1017 kg and mK/mEarth ~ 2%. These values correspond to intrinsic Earth heat flux in ~300 TW. The most part of this flux goes up in rift zones as a heated gases. Argo Project results and the measurements of the Moon intrinsic heat flux support the existence of such a big flux. So large of U, Th, K abundances were predicted by Adjusted Hydridic Earth model

On Geoneutrinos

Experimental data on geoneutrinos allow to admit that masses of U, Th and K in the Earth can be up to mU = 1.7 · 1017 kg, mTh = 6.7 · 1017 kg and mK/mEarth ~ 2%. These values correspond to intrinsic Earth heat flux in ~300 TW. The most part of this flux goes up in rift zones as a heated gases. Argo Project results and the measurements of the Moon intrinsic heat flux support the existence of such a big flux. So large of U, Th, K abundances were predicted by Adjusted Hydridic Earth model

New synthesis of trimethylsilyldiphenylphosphinite

<p>A series of novel synthetically important reactions has been developed for the quick convenient and high-yield preparation of trimethylsilyl diphenylphosphinite, a valuable for the synthesis of functionalized alkyldiphenylphosphine oxide by Arbuzov reaction. Initial compounds are (1-hydroxy-1-methylethyl)diphenylphosphine oxide and hexamethyldisilazane, bis(trimethylsilyl)acetamide, diethyl(trimethylsilyl)amine, trimethylchlorosilane.</p

On Geoneutrinos

Experimental data on geoneutrinos allow to admit that masses of U, Th and K in the Earth can be up to mU = 1.7 · 1017 kg, mTh = 6.7 · 1017 kg and mK/mEarth ~ 2%. These values correspond to intrinsic Earth heat flux in ~300 TW. The most part of this flux goes up in rift zones as a heated gases. Argo Project results and the measurements of the Moon intrinsic heat flux support the existence of such a big flux. So large of U, Th, K abundances were predicted by Adjusted Hydridic Earth model

Towards 14C-free liquid scintillator

A series of measurements has been started where the 14C concentration is determined from several liquid scintillator samples. A dedicated setup has been designed and constructed with the aim of measuring concentrations smaller than 10−18. Measurements take place in two underground laboratories: in the Baksan Neutrino Observatory, Russia, and in the new Callio Lab in the Pyhäsalmi mine, Finland. Low-energy neutrino detection with a liquid scintillator requires that the intrinsic 14C concentration in the liquid is extremely low. In the Borexino CTF detector the concentration of 2 × 10−18 has been achieved being the lowest value ever measured. In principle, the older the oil or gas source that the liquid scintillator is derived from and the deeper it situates, the smaller the 14C concentration is supposed to be. This, however, is not generally the case and the concentration is probably due to the U and Th content of the local environment.peerReviewe

Measuring the ¹⁴C content in liquid scintillators

Abstract In order to detect low-energy neutrinos, for example the solar neutrinos from the ppchain (with the maximum neutrino energy of approximately 400 keV) requires that the intrinsic ¹⁴C content in a liquid scintillator is at extremely low level. In the Borexino detector, a 300-ton liquid scintillation detector at Gran Sasso, Italy, the ratio of ¹⁴C to ¹²C of approximately 2 × 10⁻¹⁸ has been achieved. It is the lowest value ever measured. The detector situates underground at the depth of 3200 mwe (1200 m). ¹⁴C cannot be removed from liquid scintillators by chemical methods, or by other methods in large quantities (liters). In principle, the older is the oil or gas source that the liquid scintillator is made of and the deeper it situates, the smaller should be the ¹⁴C-to-¹²C ratio. This, however, is not generally the case, and the ratio depends on the activity (U and Th content) in the environment of the source. We have started a series of measurements where the ¹⁴C-to-¹²C ratio will be measured from liquid scintillator samples. The measurements take place in two underground laboratories: in the Pyhäsalmi mine, Finland, at the depth of 4000 mwe (1400 meters) and at the Baksan Underground Laboratory, Russia at 4800 mwe, for reducing and better understanding systematical uncertainties. There will be about ten samples with the known origin, each of them 2 litres. The liquid scintillator vessel, light quides and low-active PMTs will be shielded with thick layers copper and lead. Nitrogen flow is used to reduce the radon background. The aim is to measure ratios smaller than 10⁻¹⁸, if such samples exists. One measurement takes several weeks