9,062 research outputs found
Relativistic general-order coupled-cluster method for high-precision calculations: Application to Al+ atomic clock
We report the implementation of a general-order relativistic coupled-cluster
method for performing high-precision calculations of atomic and molecular
properties. As a first application, the static dipole polarizabilities of the
ground and first excited states of Al+ have been determined to precisely
estimate the uncertainty associated with the BBR shift of its clock frequency
measurement. The obtained relative BBR shift is -3.66+-0.44 for the 3s^2
^1S_0^0 --> 3s3p ^3P_0^0 transition in Al+ in contrast to the value obtained in
the latest clock frequency measurement, -9+-3 [Phys. Rev. Lett. 104, 070802
(2010)]. The method developed in the present work can be employed to study a
variety of subtle effects such as fundamental symmetry violations in atoms.Comment: 4 pages, 3 tables, submitte
Spectacular Role of Electron Correlation in the Hyperfine Interactions in States in Alkaline Earth Ions
The low-lying n(=3,4,5)d states alkaline earth ions are of vital
importance in a number of different physical applications. The hyperfine
structure constants of these states are characterized by unusually strong
electron correlation effects. Relativistic coupled-cluster theory has been
employed to carry out {\it ab initio} calculations of these constants. The role
of the all order core-polarization effects was found to be decisive in
obtaining good agreement of the results of our calculations with accurate
measurements. The present work is an apt demonstration of the power of the
coupled-cluster method to cope with strongly interacting configurations.Comment: Submitted to Physical Review Letters, 3 figures and 5 table
BTZ Black Hole with Chern-Simons and Higher Derivative Terms
The entropy of a BTZ black hole in the presence of gravitational Chern-Simons
terms has previously been analyzed using Euclidean action formalism. In this
paper we treat the BTZ solution as a two dimensional black hole by regarding
the angular coordinate as a compact direction, and use Wald's Noether charge
method to calculate the entropy of this black hole in the presence of higher
derivative and gravitational Chern-Simons terms. The parameters labelling the
black hole solution can be determined by extremizing an entropy function whose
value at the extremum gives the entropy of the black hole.Comment: LaTeX file, 11 page
INFLUENCE OF FERTILIZER AND WEED MANAGEMENT ON YIELD AND NUTRIENT UPTAKE IN ONION (Allium cepa L.)
A field experiment was conducted to find out appropriate nutrient and weed management practices for yield maximization and nutrient uptake of onion during rabi 2018-19 at the experimental plot of Regional Research and Technology Transfer Station, Keonjhar of Odisha. The experiment was laid out in Split plot technique with fifteen treatments viz., Main plot belongs to Nutrient management (N) with treatments i.e. N1- Soil test based fertilizer recommendation (STBFR), N2 - 50% STBFR + FYM (Based on N requirement), N3-STBFR + Sulphur), while Subplots belongs to weed management (W) with treatments viz., W1- Pendimethalin (PE) @ 0.8 Lha-1, W2- Oxyflurofen (PE) @ 0.2 Lha-1, W3- Pendimethalin (PE) @ 0.8 Lha-1+ one hand weeding at 25 days after transplanting(DAT), W4-Oxyflurofen (PE) @ 0.2 Lha-1+ one hand weeding at 25 days after transplanting(DAT), W5- one hand weeding at 25 days after transplanting (DAT). The highest onion bulb yield of 16.72 t ha-1 was obtained under the treatment applied with Pendimethalin (PE) @ 0.8 Lha-1 along with one hand weeding at 25 DAT, followed by Oxyfluorfen 0.2Lha-1pre-emergence + 1 hand weeding at 25 DAT (15. 88 t ha-1). The treatment combination of N2W3 (96.83, 16.80, 57.73 kg ha-1) was recorded the highest N, P, and K uptake by crops respectively while N3W3 (51.39 kg ha-1) was recorded as the highest S uptake by a crop over the rest of the treatments
Separation energies of light nuclei with atomic number from 1 to 20
The 1n and 1p halo nuclei from atomic number 1 to 20 are discussed here to calculate the variation of separation energy with mass defect and binding energy. Semi-empirical mass formula and shell model are the methods applied here. The appearances of p- and r-branches satisfying the selection rules for different isotopes of nuclides are discussed
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