82,561 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
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
Real-time flutter analysis
The important algorithm issues necessary to achieve a real time flutter monitoring system; namely, the guidelines for choosing appropriate model forms, reduction of the parameter convergence transient, handling multiple modes, the effect of over parameterization, and estimate accuracy predictions, both online and for experiment design are addressed. An approach for efficiently computing continuous-time flutter parameter Cramer-Rao estimate error bounds were developed. This enables a convincing comparison of theoretical and simulation results, as well as offline studies in preparation for a flight test. Theoretical predictions, simulation and flight test results from the NASA Drones for Aerodynamic and Structural Test (DAST) Program are compared
Linear Phase Second Order Recursive Digital Integrators and Differentiators
In this paper, design of linear phase second order recursive digital integrators and differentiators is discussed. New second order integrators have been designed by using Genetic Algorithm (GA) optimization method. Thereafter, by modifying the transfer function of these integrators appropriately, new digital differentiators have been obtained. The proposed digital integrators and differentiators accurately approximate the ideal ones and have linear phase response over almost entire Nyquist frequency range. The proposed operators also outperform the existing operators in terms of both magnitude and phase response
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