137,739 research outputs found
Experimental investigation of the low molecular weight fluoropolymer for the ultracold neutrons storage
The experimental setup for examining the low-molecular-weight fluoropolymer
CF(CF-O-CF-O-(CFCF, which is a
promising coating material for the walls of storage chambers for ultracold
neutrons, is described. The results are detailed. The measurement data are
interpreted in the model of a multilayer complex quantum-mechanical potential
of the chamber walls.Comment: Corrected version of the paper published in Phys. of Part. and Nucl
Lett., 15 (No.5) (2018) 54
Induced interactions in dilute atomic gases and liquid helium mixtures
In dilute mixtures of two atomic gases, interactions between two minority
atoms acquire a contribution due to interaction with the majority component.
Using thermodynamic arguments, we derive expressions for this induced
interaction for both fermions and bosons for arbitrary strength of the
interaction between the two components. Implications of the work for the theory
of dilute solutions of He in liquid He are discussed.Comment: 7 pages, 1 figure, NORDITA-2012-3
Solar neutrinos: the SNO salt phase results and physics of conversion
We have performed analysis of the solar neutrino data including results from
the SNO salt phase as well as the combined analysis of the solar and the
KamLAND results. The best fit values of neutrino parameters are Delta m^2 =
7.1e-5 eV^2, tan^2\theta = 0.40 with the boron flux f_B = 1.04. New SNO results
strongly disfavor maximal mixing and the h-LMA region (Delta m^2 > 1e-4 eV^2)
which is accepted now at the 3-sigma level. We find the 3-sigma upper bounds:
Delta m^2 < 1.7e-4$ eV^2 and tan^2\theta < 0.64, and the lower bound Delta m^2
> 4.8e-5 eV^2. Non-zero 13-mixing does not change these results significantly.
The present data determine quantitatively the physical picture of the solar
neutrino conversion. At high energies relevant for SNO and Super-Kamiokande the
deviation of the effective survival probability from the non-oscillatory value
is about 10 - 14%. The oscillation effect contribution to this difference about
10% and the Earth regeneration is about 3 - 4%. At low energies (E < 1 MeV) the
matter corrections to vacuum oscillation effect are below 5%. The predictions
for the forthcoming measurements are given which include the spectral
distortion and CC/NC ratio at SNO, the Day-Night asymmetry, the KamLAND
spectrum and rate.Comment: figures and some numbers corrected, discussion of coherence loss
added, number of pages slightly change
Microwave Nanotube Transistor Operation at High Bias
We measure the small signal, 1 GHz source-drain dynamical conductance of a
back-gated single-walled carbon nanotube field effect transistor at both low
and high dc bias voltages. At all bias voltages, the intrinsic device dynamical
conductance at 1 GHz is identical to the low frequency dynamical conductance,
consistent with the prediction of a cutoff frequency much higher than 1 GHz.
This work represents a significant step towards a full characterization of a
nanotube transistor for RF and microwave amplifiers.Comment: 3 pages, 4 figure
The Deuteron Spin Structure Functions in the Bethe-Salpeter Approach and the Extraction of the Neutron Structure Function
The nuclear effects in the spin-dependent structure functions and
are calculated in the relativistic approach based on the Bethe-Salpeter
equation with a realistic meson-exchange potential.
The results of calculations are compared with the non-relativistic
calculations. The problem of extraction of the neutron spin structure function,
, from the deuteron data is discussed.Comment: (Talk given at the SPIN'94 International Symposium, September 15-22,
1994, Bloomington, Indiana), 6 pages, 5 figures, Preprint Alberta Thy 29-9
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