Thermal operator representation of finite temperature graphs. II

Journal Article · Wed Mar 15 04:00:00 EST 2006 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.73.065010· OSTI ID:20782681

Brandt, F T; Frenkel, J ^[1]; Das, Ashok ^[2]; Espinosa, Olivier ^[3]; Perez, Silvana ^[4]

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1. Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil)
2. Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627-0171 (United States)
3. Departamento de Fisica, Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile)
4. Departamento de Fisica, Universidade Federal do Para, Belem, Para 66075-110 (Brazil)

Using the mixed space representation, we extend our earlier analysis to the case of Dirac and gauge fields and show that in the absence of a chemical potential, the finite temperature Feynman diagrams can be related to the corresponding zero temperature graphs through a thermal operator. At nonzero chemical potential we show explicitly in the case of the fermion self-energy that such a factorization is violated because of the presence of a singular contact term. Such a temperature dependent term which arises only at finite density and has a quadratic mass singularity cannot be related, through a regular thermal operator, to the fermion self-energy at zero temperature which is infrared finite. Furthermore, we show that the thermal radiative corrections at finite density have a screening effect for the chemical potential leading to a finite renormalization of the potential.

• OSTI ID: 20782681
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 6 Vol. 73; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
DENSITY
FACTORIZATION
FERMIONS
FEYNMAN DIAGRAM
GAUGE INVARIANCE
MASS
POTENTIALS
QUANTUM FIELD THEORY
RADIATIVE CORRECTIONS
RENORMALIZATION
SELF-ENERGY
SINGULARITY
TEMPERATURE DEPENDENCE