65,017 research outputs found

    Heavy Quarkonium Potential Model and the 1P1{}^1P_1 State of Charmonium

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    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 3PJ{}^3P_J states and the 1P1{}^1P_1 state of ccˉc\bar{c} does not provide a direct test of the color hyperfine interaction in heavy quarkonia. Our theoretical value for the mass of the 1P1{}^1P_1 state is in agreement with the experimental result, and its E1 transition width is 341.8~keV. The mass of the ηc\eta_c' 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

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    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

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    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 ccˉc\bar{c} and bbˉb\bar{b}, the potential for a light-heavy system has a complicated dependence on the light and heavy quark masses mm and MM, and it contains a spin-orbit mixing term. We have obtained excellent results for the observed energy levels of D0D^0, DsD_s, B0B^0, and BsB_s, 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 B0B^0 and BsB_s energy levels provided that M1M^{-1} and M1lnMM^{-1}\ln M corrections are taken into account in the quark-antiquark interactions. It does not, however, provide equally good results for the energy levels of D0D^0 and DsD_s, which indicates that the effective theory can be applied more accurately to the bb quark than the cc 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

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    We have investigated BcB_c 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 EE1 transition widths. We also find, rather surprisingly, that although BcB_c is not a light-heavy system, the heavy quark effective theory with the inclusion of the mb1m_b^{-1} and mb1lnmbm_b^{-1}\ln m_b corrections is as successful for BcB_c as it is for BB and BsB_s.Comment: 10 page ReVTeX pape

    Indian GDP, 1600-1871 : some preliminary estimates and a comparison with Britain.

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    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

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    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

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    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
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