# S parameter at nonzero temperature and chemical potential

## Abstract

We compute the finite-temperature and matter density corrections to the S-parameter at the one-loop level. At nonzero temperature T and matter density {mu} Lorentz symmetry breaks and therefore we suggest a suitable generalization of the S-parameter. By computing the plasma correction, we discover a reduction of the S-parameter in the physically relevant region of small external momenta for any nonzero {mu} and T. In particular, the S-parameter vanishes at small m/T, where m is the mass of the fermions, due to the finite extent of the temporal direction. Our results are directly applicable to the determination of the S-parameter via first-principle lattice simulations performed with antiperiodic boundary conditions in the temporal direction.

- Authors:

- CP3-Origins and DIAS, Campusvej 55, DK-5230 Odense M (Denmark)

- Publication Date:

- OSTI Identifier:
- 21607825

- Resource Type:
- Journal Article

- Journal Name:
- Physical Review. D, Particles Fields

- Additional Journal Information:
- Journal Volume: 84; Journal Issue: 7; Other Information: DOI: 10.1103/PhysRevD.84.075022; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0556-2821

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BOUNDARY CONDITIONS; COMPUTERIZED SIMULATION; CORRECTIONS; DENSITY; FERMIONS; LATTICE FIELD THEORY; MASS; PLASMA; SYMMETRY; SYMMETRY BREAKING; CONSTRUCTIVE FIELD THEORY; FIELD THEORIES; PHYSICAL PROPERTIES; QUANTUM FIELD THEORY; SIMULATION

### Citation Formats

```
Soendergaard, Ulrik Ishoej, Pica, Claudio, and Sannino, Francesco.
```*S parameter at nonzero temperature and chemical potential*. United States: N. p., 2011.
Web. doi:10.1103/PHYSREVD.84.075022.

```
Soendergaard, Ulrik Ishoej, Pica, Claudio, & Sannino, Francesco.
```*S parameter at nonzero temperature and chemical potential*. United States. doi:10.1103/PHYSREVD.84.075022.

```
Soendergaard, Ulrik Ishoej, Pica, Claudio, and Sannino, Francesco. Sat .
"S parameter at nonzero temperature and chemical potential". United States. doi:10.1103/PHYSREVD.84.075022.
```

```
@article{osti_21607825,
```

title = {S parameter at nonzero temperature and chemical potential},

author = {Soendergaard, Ulrik Ishoej and Pica, Claudio and Sannino, Francesco},

abstractNote = {We compute the finite-temperature and matter density corrections to the S-parameter at the one-loop level. At nonzero temperature T and matter density {mu} Lorentz symmetry breaks and therefore we suggest a suitable generalization of the S-parameter. By computing the plasma correction, we discover a reduction of the S-parameter in the physically relevant region of small external momenta for any nonzero {mu} and T. In particular, the S-parameter vanishes at small m/T, where m is the mass of the fermions, due to the finite extent of the temporal direction. Our results are directly applicable to the determination of the S-parameter via first-principle lattice simulations performed with antiperiodic boundary conditions in the temporal direction.},

doi = {10.1103/PHYSREVD.84.075022},

journal = {Physical Review. D, Particles Fields},

issn = {0556-2821},

number = 7,

volume = 84,

place = {United States},

year = {2011},

month = {10}

}