Müller, Daniel (2013)
QCD at finite density with Dyson-Schwinger equations.
Technische Universität Darmstadt
Ph.D. Thesis, Primary publication
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Item Type: | Ph.D. Thesis | ||||
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Type of entry: | Primary publication | ||||
Title: | QCD at finite density with Dyson-Schwinger equations | ||||
Language: | English | ||||
Referees: | Wambach, Prof. Dr. Jochen ; Buballa, PD Dr. Michael | ||||
Date: | 2013 | ||||
Place of Publication: | Darmstadt | ||||
Date of oral examination: | 27 May 2013 | ||||
Abstract: | In this work we investigate QCD at finite density with Dyson-Schwinger equations. In the first part we consider color-superconducting phases, which occur at high densities through the formation of quark-quark pairs. We describe 2SC and CFL phases with massive strange quarks. We calculate the phase diagram in a hard-thermal-loop / hard-dense-loop approximation which describes the back-coupling of massless quarks to the gluons. We fixed the vertex parameters to a chiral critical temperature of Tc=150 MeV. This approximation results in low critical temperatures for the color-superconducting phases around 20-30 MeV and a too large pion decay constant. To improve the truncation we couple the full color-superconducting quark propagator back to the gluons. In addition to more realistic vacuum observables also the critical temperatures increase to 40-60 MeV. We find a dominant CFL phase at high densities, while at intermediate chemical potential, the ground state is a 2SC phase which also extents to a small band between CFL and normal conducting phase. We also calculate Debye and Meissner masses of the gluons, which can reproduce the results of weak-coupling calculations. In the second part of this work we consider chiral condensates with the possibility of spatial modulations. We investigate 1-dimensional modulations with plane-wave shape, which oscillate between a scalar and a pseudoscalar condensate, in the Dyson-Schwinger formalism. We find an inhomogeneous phase that covers the original first-order chiral phase transition, which is in agreement with similar model calculations. |
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Uncontrolled Keywords: | color superconductivity, inhomogeneous phases, Dyson-Schwinger equations, strong interaction, QCD phase diagram | ||||
URN: | urn:nbn:de:tuda-tuprints-34836 | ||||
Classification DDC: | 500 Science and mathematics > 530 Physics | ||||
Divisions: | 05 Department of Physics > Institute of Nuclear Physics | ||||
Date Deposited: | 21 Jun 2013 07:49 | ||||
Last Modified: | 21 Jun 2013 07:49 | ||||
URI: | https://tuprints.ulb.tu-darmstadt.de/id/eprint/3483 | ||||
PPN: | 386276072 | ||||
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