4,004 research outputs found
The {\alpha}-Decay Chains of the Isotopes using Relativistic Mean Field Theory
We study the binding energy, root-mean-square radius and quadrupole
deformation parameter for the synthesized superheavy element Z = 115, within
the formalism of relativistic mean field theory. The calculation is dones for
various isotopes of Z = 115 element, starting from A = 272 to A = 292. A
systematic comparison between the binding energies and experimental data is
made.The calculated binding energies are in good agreement with experimental
result. The results show the prolate deformation for the ground state of these
nuclei. The most stable isotope is found to be 282115 nucleus (N = 167) in the
isotopic chain. We have also studied Q{\alpha} and T{\alpha} for the
{\alpha}-decay chains of 115.Comment: 12 Pages 6 Figures 3 Table
Relativistic mean field study of the properties of Z=117 nucleus and the decay chains of 117 isotopes
We have calculated the binding energy, root-mean-square radius and quadrupole
deformation parameter for the recently synthesized superheavy element Z=117,
using the axially deformed relativistic mean field (RMF) model. The calculation
is extended to various isotopes of Z=117 element, strarting from A=286 till
A=310. We predict almost spherical structures in the ground state for almost
all the isotopes. A shape transition appears at about A=292 from prolate to a
oblate shape structures of Z=117 nucleus in our mean field approach. The most
stable isotope (largest binding energy per nucleon) is found to be the
117 nucleus. Also, the Q-value of -decay and the
half-lives are calculated for the -decay chains of
117 and 117, supporting the magic numbers at N=172 and/ or 184.Comment: 6 Pages and 8 Figure
Constraining the Surface Curvature of an Anisotropic Neutron Star
The anisotropy of pressure arises due to the various complex phenomena that
happen inside the neutron star (NS). In this study, we calculate the degree of
anisotropy inside the NS using the scalar pressure anisotropy model.
Macroscopic properties such as mass, radius, compactness, redshift, tidal
deformability, the moment of inertia, and surface curvature (SC) are computed
for the anisotropic NS with the equation of states spanning from relativistic
to nonrelativistic cases. The variation of SC as the functions of the
above-mentioned quantities are computed by changing the degree of anisotropy.
Pressure anisotropy has significant effects on the magnitude of SC. The
universal relations between the canonical SC and SC are
studied. From the GW170817 tidal deformability data constraints on SC are found
to be SC for , and
respectively.Comment: 8 pages, 6 figures, 1 table, Published in Phys. Rev.
Effect of the -cut potential on the properties of neutron stars with or without a hyperonic core
Motivated by the recent observation of high-mass pulsars (), we employ the -cut potential on the equation of state
(EOS) of high-density matter and the properties of neutron stars within the
relativistic mean-field (RMF) model using TM1 parameter set. The
-cut potential is known to reduce the contributions of the
field, resulting in a stiffer EOS at high densities and hence leading to larger
neutron star masses without affecting the properties of nuclear matter at
normal saturation density. We also analyzed the effect of the same on pure
neutron matter and also on the neutron star matter with and without hyperonic
core and compared it with the available theoretical, experimental, and
observational data. The corresponding tidal deformability () is
also calculated. With the choice of meson-hyperon coupling fixed to
hypernuclear potentials, we obtain increase in mass by
employing the -cut potential for . Our results are in good
agreement with various experimental constraints and observational data,
particularly with the GW170817 data.Comment: 7 Pages, 6 Figures and 1 Table (Accepted in Phys. Rev. C
Spatial and temporal variation of phytoplankton in hot spring of Atri, Odisha, India
Seasonal dynamics of phytoplanktons along with various physicochemical parameters were recorded in the hot spring of Atri, Odisha during the year 2010-2011. The study was carried out to ascertain the phytoplanktons diversity in relation to the changing physico-chemical parameters in an extreme condition of the hot spring on seasonal basis. Total twenty eight genera having forty two species of phytoplanktons were recorded under the following classes, viz. Chlorophyceae, Cyanophyceae Bacillariophyceae and Euglenophyceae. Chlorophyceae was found to be dominating class contributing 40% of the total. The highest numbers of phytoplankton species were recorded during summer season with an average of 11, 3,000 cells/liter. Dominant species identified were Anabaena aequalis, Closterium ehrenbergii Meneghini ex Ralfs, Eudorina sp., Merismopedia punctata Meyen, Microcystis aeruginosa (Kützing) Kützing, Navicula membranacea Cleve, Oscillatoria sp., Pediastrum simplex Meyen, Scenedesmus quadricauda Chodat. Correlation studies of phytoplankton with physicochemical variables indicate a significant positive correlation with chlorophyll-a, alkalinity and nitrate concentration at p≤0.01 and p≤0.05
Warm dense matter and cooling of supernovae remnants
We study the thermal effects on the nuclear matter (NM) properties such as
binding energy, incompressibility, free symmetry energy and its coefficients
using NL3, G3 and IU-FSU parameter sets of relativistic mean-field models.
These models being consistent with the properties of cold NM, have also been
used to study the effect of temperature by incorporating the Fermi function.
The critical temperature for the liquid-gas phase transition in the symmetric
NM is found to be 14.60, 15.37 and 14.50 MeV for NL3, G3 and IU-FSU parameter
sets respectively, which is in excellent agreement with previous theoretical
and experimental studies. We inspect that the properties related to second
differential coefficient of the binding energy and free symmetry energy at
saturation density ( i.e. K 0 (n, T ) and Q sym,0) exhibit the contrary effects
for NL3 and G3 parameters as the temperature increases. We find that the
prediction of saturated curvature parameter ( K sym,0 ) for G3 equation of
state at finite temperature favour the combined analysis of K sym,0 for the
existence of massive pulsars, gravitational waves from GW170817 and NICER
observations of PSR J0030+0451. Further, we investigate the cooling mechanism
of newly born stars through neutrino emissivity controlled by direct Urca
process and instate some interesting remarks about neutrino emissivity. We also
deliberate the effect of temperature on the M-R profile of Proto-Neutron star.Comment: 15 pages, 11 figures. 3 tables, Published in EPJ
Theory for the photon statistics of random lasers
A theory for the photon statistics of a random laser is presented. Noise is
described by Langevin operators, where both fluctuations of the electromagnetic
field and of the medium are included. The theory is valid for all lasers with
small outcoupling when the laser cavity is large compared to the wavelength of
the radiation. The theory is applied to a chaotic laser cavity with a small
opening. It is known that a large number of modes can be above threshold
simultaneously in such a cavity. It is shown the amount of fluctuations is
increased compared to the Poissonian value by an amount that depends on that
number
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