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arXiv · 1107.1802

S-parameter at Non-Zero Temperature and Chemical Potential

Ulrik Ishøj Søndergaard·Claudio Pica·Francesco Sannino
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Abstract

We compute the finite-temperature and matter density corrections to the S-parameter at the one loop level. At non-zero temperature T and matter density 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 non-zero chemical potential 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 anti-periodic boundary conditions in the temporal direction.

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Ulrik Ishøj Søndergaard, Claudio Pica, Francesco Sannino. 2011-07-09. S-parameter at Non-Zero Temperature and Chemical Potential. https://doi.org/10.1103/physrevd.84.075022

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