STUDY OF NUCLEAR BREMSSTRAHLUNG IN THE MODEL INDEPENDENT APPROACH.
Item
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Title
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STUDY OF NUCLEAR BREMSSTRAHLUNG IN THE MODEL INDEPENDENT APPROACH.
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Identifier
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AAI8023673
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identifier
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8023673
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Creator
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LIU, CHENG-KUANG.
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Contributor
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Ming-Kung Liou
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Date
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1980
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Language
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English
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Publisher
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City University of New York.
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Subject
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Physics, Nuclear
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Abstract
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The proton-carbon, pion-proton and proton-proton bremsstrahlung processes have been theoretically studied by using two different model-independent approaches, the soft-photon approximation and the Feshbach-Yennie approximation.;The bremsstrahlung cross section for the scattering of protons by ('12)C near the 1.7-MeV resonance has been measured by the Bologna group and the Brooklyn group. These data have been analyzed by some authors using only the principal term of the Feshbach-Yennie approximation. In this study, we have included in our calculations the correction terms and have extracted the time delay in the p-('12)C reaction from the data of the Brooklyn group. Our calculation shows that the structure due to the 1.7-MeV resonance can be described successfully by the Feshbach-Yennie approximation only if the correction terms are included.;The ('+)p process near the (1236) has been systematically studied by an experimental group at UCLA. Many calculations have been performed, but, only the calculation of Nefkens et al. agrees well with the experimental data in most cases. Recently, Liou and Nutt reported a calculation using the soft-photon approximation and their results agree very well with experiment for coplanar events. We have extended their calculation to noncoplanar cases and have found that the soft-photon approximation of Liou and Nutt can describe the experimental data very well not only for coplanar cases but also for noncoplanar cases for most photon angles. In addition, we have also used the Feshbach-Yennie approximation to calculate the ('+)p cross sections. This approximation always predicts a bump in the bremsstrahlung spectrum, although the bump may be small for some photon angles. In most cases, the predicted cross sections are in good agreement with the UCLA data. However, the data for some angles can only be described by the Feshbach-Yennie approximation, and the peak cross section is too large at some angles.;We have applied the soft-photon approximation of Liou and Nutt to calculate the proton-proton bremsstrahlung (pp ) cross section and have compared our results with the experimental data at 730, 157, 48 and 42 MeV. We have found that we can use the soft-photon approximation to calculate the R-type cross section without any difficulty, but we cannot use the same approximation to predict the H-type cross section without some ambiguity. Our result for the R-type cross section at low photon energy is in very good agreement with experiment, but the result at high photon energy is lower than the experimental data for some photon angles. This indicates that other contributions or higher order terms are important for these photon angles. We have also applied the Feshbach-Yennie approximation to the pp process at 730-MeV taking into account the principal and correction terms. As a result, we have found that the Feshbach-Yennie approximation gives results which are in very good agreement with experiment for low photon energy. For high photon energy, the agreement with data is also good for most cases, but the predictions are lower than the experimental data for some photon angles.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Physics
