Vector meson mass in medium and dilepton production from heavy-ion collisions /
In this dissertation, hadron properties at finite density and temperature are investigated. In particular, the Walecka model is used to study the effective mass of a nucleon in a dense medium. The model is further generalized to evaluate the mass shift of vector mesons, such as the rho, omega and...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1997.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=736824881&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | In this dissertation, hadron properties at finite density and temperature are investigated. In particular, the Walecka model is used to study the effective mass of a nucleon in a dense medium. The model is further generalized to evaluate the mass shift of vector mesons, such as the rho, omega and phi mesons, and the rho-photon coupling at finite density and temperature. The latter is of interest for understanding how the vector dominance is modified in medium. Both vacuum and particle-hole polarization are included. It is found that vector meson masses and the photon-rho coupling constant both decrease with increasing density and/or temperature. These results are then compared with those from other approaches. To probe the properties of vector mesons in a medium, dilepton production from a hot hadronic matter is studied. Using an effective chiral Lagrangian, which is both gauge and chiral invariant, dilepton spectra from both pion-pion annihilation and pion-rho scattering are calculated. With free meson masses and coupling constants, it is found that for dileptons with invariant mass around the rho meson mass, contributions from these two processes are comparable. However, the contribution from pion-rho scattering becomes more important if in-medium meson masses and coupling constants are used. The relevance of this result to the observed enhancement of low-mass dileptons in nucleus-nucleus collisions at Super Proton Synchrotron (SPS) energy by the Cerenkov Electron Spectrometer (CERES) collaboration is discussed. |
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| Item Description: | Vita. "Major Subject: Physics". |
| Physical Description: | xi, 94 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 73-77. |