16,204 research outputs found
Energy Landscape and Overlap Distribution of Binary Lennard-Jones Glasses
We study the distribution of overlaps of glassy minima, taking proper care of
residual symmetries of the system. Ensembles of locally stable, low lying
glassy states are efficiently generated by rapid cooling from the liquid phase
which has been equilibrated at a temperature . Varying , we
observe a transition from a regime where a broad range of states are sampled to
a regime where the system is almost always trapped in a metastable glassy
state. We do not observe any structure in the distribution of overlaps of
glassy minima, but find only very weak correlations, comparable in size to
those of two liquid configurations.Comment: 7 pages, 5 figures, uses europhys-style. Minor notational changes,
typos correcte
Study of Dissipative Collisions of Ne (7-11 MeV/nucleon) + Al
The inclusive energy distributions of complex fragments (3 Z 9)
emitted in the reactions Ne (145, 158, 200, 218 MeV) + Al have
been measured in the angular range 10 - 50. The fusion-fission and
the deep-inelastic components of the fragment yield have been extracted using
multiple Gaussian functions from the experimental fragment energy spectra. The
elemental yields of the fusion-fission component have been found to be fairly
well exlained in the framework of standard statistical model. It is found that
there is strong competition between the fusion-fission and the deep-inelastic
processes at these energies. The time scale of the deep-inelastic process was
estimated to be typically in the range of 10 - 10 sec.,
and it was found to decrease with increasing fragment mass. The angular
momentum dissipations in fully energy damped deep-inelastic process have been
estimated from the average energies of the deep-inelastic components of the
fragment energy spectra. It has been found that, the estimated angular momentum
dissipations, for lighter fragments in particular, are more than those
predicted by the empirical sticking limit.Comment: 16 pages, 9 figure
Onset of deformation at in Bi nuclei
The high spin states in Bi has been studied by -ray
spectroscopic method using the Ta(Ne, 6n) fusion evaporation
reaction at 130 MeV. The coincidence data were taken using an
array of 8 clover HPGe detectors. The spin and parity assignments of the
excited states have been made from the measured directional correlation from
oriented states (DCO) ratios and integrated polarization asymmetry (IPDCO)
ratios. The results show, for the first time, the evidence of a rotational like
band based on a 13/2 band head in this nucleus, indicating the onset of
deformation at neutron number for the Bismuth isotopes. The results
obtained were found to be consistent with the prediction of the total Routhian
surface calculations using Woods Saxon potential. The same calculations also
predict a change in shape from oblate to triaxial in Bi at high
rotational frequency
Evidence of large nuclear deformation of S formed in Ne + C reaction
Deformations of hot composite S formed in the reaction Ne
( 7 -- 10 MeV/nucleon) + C have been estimated from the respective
inclusive -particle evaporation spectra. The estimated deformations for
S have been found to be much larger than the `normal' deformations
of hot, rotating composites at similar excitations. This further confirms the
formation of highly deformed long-lived configuration of Ne + C
at high excitations ( 70 -- 100 MeV) -- which was recently indicated from
the analysis of the complex fragment emission data for the same system.
Exclusive -particle evaporation spectra from the decay of hot composite
S also show similar behaviour.Comment: 9 pages, 6 figure
Diffuse solar radiation and associated meteorological parameters in India
International audienceSolar diffuse radiation data including global radiation, shortwave and longwave balances, net radiation and sunshine hours have been extensively analyzed to study the variation of diffuse radiation with turbidity and cloud discharges appearing in the form of atmospherics over the tropics. Results of surface radiation measurements at Calcutta, Poona, Delhi and Madras are presented together with some meteorological parameters. The monthly values of diffuse radiation and the monthly ratios of diffuse to global solar radiation have been examined, with a special emphasis in relation to the noise level of atmospherics at Calcutta in the very low frequency band. The results exhibit some definite seasonal changes which appear to be in close agreement with one another
Giant Dipole Resonance Width in near-Sn Nuclei at Low Temperature and High Angular Momentum
High energy gamma-rays in coincidence with low energy yrast gamma-rays have
been measured from 113Sb, at excitation energies of 109 and 122 MeV, formed by
bombarding 20Ne on 93Nb at projectile energies of 145 and 160 MeV respectively
to study the role of angular momentum (J) and temperature (T) over Giant Dipole
Resonance (GDR) width. The maximum populated angular momenta for fusion were
67hbar and 73hbar respectively for the above-mentioned beam energies. The high
energy photons were detected using a Large Area Modular BaF2 Detector Array
(LAMBDA) along with a 24-element multiplicity filter. After pre-equilibrium
corrections, the excitation energy E* was averaged over the decay steps of the
compound nucleus (CN). The average values of temperature, angular momentum, CN
mass etc. have been calculated by the statistical model code CASCADE. Using
those average values, results show the systematic increase of GDR width with T
which is consistent with Kusnezov parametrization and the Thermal Shape
Fluctuation Model. The rise of GDR width with temperature also supports the
assumptions of adiabatic coupling in the Thermal Shape Fluctuation Model. But
the GDR widths and corresponding reduced plots with J are not consistent with
the theoretical model at high spins.Comment: 19 pages, 10 figures, Submitted to Physics Review
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