Schwinger and Thirring models at finite chemical potential and temperature
The imaginary time generating functional Z for the assless Schwinger model at nonzero chemical potential mu and temperature T is studied in a torus with spatial length L. The lack of Hermiticity of the Dirac operator gives rise to a nontrivial μ- and T-dependent phase J in the effective action. When...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 1998 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/59586 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/59586 |
| Access Level: | acceso abierto |
| Palabra clave: | 51-73 Gauge-theories 2 Dimensions Density Family Matter Zero Física-Modelos matemáticos Física matemática |
| Sumario: | The imaginary time generating functional Z for the assless Schwinger model at nonzero chemical potential mu and temperature T is studied in a torus with spatial length L. The lack of Hermiticity of the Dirac operator gives rise to a nontrivial μ- and T-dependent phase J in the effective action. When the Dirac operator has no zero modes (trivial sector), we evaluate J, which is a topological contribution, and we find exactly Z, the thermodynamical partition function, the boson propagator and the thermally averaged Polyakov loop. The μ-dependent contribution of the free partition function cancels exactly the nonperturbative one from J, for L→∞, yielding a zero charge density for the system, which bosonizes at nonzero μ. The boson mass is e/√π, independent of T and μ, which is also the inverse correlation length between two opposite charges. Both the boson propagator and the Polyakov loop acquire a new T- and μ -dependent term at L→∞,. The imaginary time generating functional for the massless Thirring model at nonzero T and μ is obtained exactly in terms of the above solution of the Schwinger model in the trivial sector. For this model, the μ dependences of the thermodynamical partition function, the total fermion number density and the fermion two- point correlation function are obtained. The phase J displayed here leads to our new results and allows us to complement nontrivially previous studies on those models. |
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