63,911 research outputs found
Heavy Quarkonium Potential Model and the State of Charmonium
A theoretical explanation of the observed splittings among the P~states of
charmonium is given with the use of a nonsingular potential model for heavy
quarkonia. We also show that the recently observed mass difference between the
center of gravity of the states and the state of
does not provide a direct test of the color hyperfine interaction in heavy
quarkonia. Our theoretical value for the mass of the state is in
agreement with the experimental result, and its E1 transition width is
341.8~keV. The mass of the state is predicted to be 3622.3~MeV.Comment: 15 page REVTEX documen
Comparison of the Effects of Coconut Oil and Soyabean Oil on TSH Level and Weight Gain in Rabbits
The present study was conducted on 12 albino rabbits of either sex and weighing between 1-1.5kg to see the influence of coconut oil and soyabean oil on serum TSH levels and weight gain for a period of 12 weeks. The rabbits were divided into 2 groups of six each. Rabbits in group 1 were fed on coconut oil and in group 2 were fed on soyabean oil in addition to their standard diet. At the end of 12 weeks we found that rabbits fed on soyabean oil had significant increase in TSH levels (p= 0.003) and gained more weight (p=0.000) when compared to rabbits fed on coconut oil
Quantum-Chromodynamic Potential Model for Light-Heavy Quarkonia and the Heavy Quark Effective Theory
We have investigated the spectra of light-heavy quarkonia with the use of a
quantum-chromodynamic potential model which is similar to that used earlier for
the heavy quarkonia. An essential feature of our treatment is the inclusion of
the one-loop radiative corrections to the quark-antiquark potential, which
contribute significantly to the spin-splittings among the quarkonium energy
levels. Unlike and , the potential for a light-heavy
system has a complicated dependence on the light and heavy quark masses and
, and it contains a spin-orbit mixing term. We have obtained excellent
results for the observed energy levels of , , , and , and
we are able to provide predicted results for many unobserved energy levels. Our
potential parameters for different quarkonia satisfy the constraints of quantum
chromodynamics.
We have also used our investigation to test the accuracy of the heavy quark
effective theory. We find that the heavy quark expansion yields generally good
results for the and energy levels provided that and
corrections are taken into account in the quark-antiquark
interactions. It does not, however, provide equally good results for the energy
levels of and , which indicates that the effective theory can be
applied more accurately to the quark than the quark.Comment: 17 pages of LaTeX. To appear in Physical Review D. Complete
PostScript file is available via WWW at
http://gluon.physics.wayne.edu/wsuhep/jim/heavy.p
Bc spectroscopy in a quantum-chromodynamic potential model
We have investigated spectroscopy with the use of a
quantum-chromodynamic potential model which was recently used by us for the
light-heavy quarkonia. We give our predictions for the energy levels and the
1 transition widths. We also find, rather surprisingly, that although
is not a light-heavy system, the heavy quark effective theory with the
inclusion of the and corrections is as successful
for as it is for and .Comment: 10 page ReVTeX pape
Indian GDP, 1600-1871 : some preliminary estimates and a comparison with Britain.
This paper provides estimates of Indian GDP constructed from the output side for the period 1600-1871, and combines them with population estimates to track changes in living standards. Indian per capita GDP declined steadily. As British living standards increased from the mid-seventeenth century, India fell increasingly behind. Whereas in 1650, Indian per capita GDP was more than 80 per cent of the British level, by 1871 it had fallen to less than 15 per cent. As well as placing the origins of
the Great Divergence firmly in the early modern period, these estimates suggest a relatively prosperous India at the height of the Mughal Empire, with living standards well above bare bones subsistence
Flight test trajectory control analysis
Recent extensions to optimal control theory applied to meaningful linear models with sufficiently flexible software tools provide powerful techniques for designing flight test trajectory controllers (FTTCs). This report describes the principal steps for systematic development of flight trajectory controllers, which can be summarized as planning, modeling, designing, and validating a trajectory controller. The techniques have been kept as general as possible and should apply to a wide range of problems where quantities must be computed and displayed to a pilot to improve pilot effectiveness and to reduce workload and fatigue. To illustrate the approach, a detailed trajectory guidance law is developed and demonstrated for the F-15 aircraft flying the zoom-and-pushover maneuver
Theoretical study of reactive and nonreactive turbulent coaxial jets
The hydrodynamic properties and the reaction kinetics of axisymmetric coaxial turbulent jets having steady mean quantities are investigated. From the analysis, limited to free turbulent boundary layer mixing of such jets, it is found that the two-equation model of turbulence is adequate for most nonreactive flows. For the reactive flows, where an allowance must be made for second order correlations of concentration fluctuations in the finite rate chemistry for initially inhomogeneous mixture, an equation similar to the concentration fluctuation equation of a related model is suggested. For diffusion limited reactions, the eddy breakup model based on concentration fluctuations is found satisfactory and simple to use. The theoretical results obtained from these various models are compared with some of the available experimental data
- …