https://doi.org/10.1140/epja/i2008-10652-0
Regular Article - Theoretical Physics
Neutron stars within the SU(2) parity doublet model
1
Frankfurt Institute for Advanced Studies, J.W. Goethe-Universität, D-60438, Frankfurt am Main, Germany
2
Institut für Theoretische Physik, J.W. Goethe Universität, D-60438, Frankfurt am Main, Germany
3
Center for Scientific Computing, J.W. Goethe-Universität, D-60438, Frankfurt am Main, Germany
Received:
21
May
2008
Accepted:
17
September
2008
Published online:
15
October
2008
The equation of state of beta-stable and charge neutral nucleonic matter is computed within theSU(2) parity doublet model in mean-field and in the relativistic Hartree approximation. The mass of the chiral partner of the nucleon is assumed to be 1200MeV. The transition to the chiral restored phase turns out to be a smooth crossover in all the cases considered, taking place at a baryon density of just 2ρ0 . The mass-radius relations of compact stars are calculated to constrain the model parameters from the maximum mass limit of neutron stars. It is demonstrated that chiral symmetry starts to be restored, which in this model implies the appearance of the chiral partners of the nucleons, in the center of neutron stars. However, the analysis of the decay width of the assumed chiral partner of the nucleon poses limits on the validity of the present version of the model to describe vacuum properties.
PACS: 26.60.-c Nuclear matter aspects of neutron stars – / 21.65.Cd Asymmetric matter, neutron matter –
© SIF, Springer-Verlag Berlin Heidelberg, 2008
