Delta isobars in neutron stars
1 Dip. di Fisica e Scienze della Terra dell’Università di Ferrara and INFN Sez. di Ferrara, Via Saragat 1, I-44100 Ferrara, Italy
2 Department of Applied Science and Technology, Politecnico di Torino, Italy and Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Italy
a e-mail: firstname.lastname@example.org
Published online: 29 May 2015
The appearance of delta isobars in beta-stable matter is regulated by the behavior of the symmetry energy at densities larger than saturation density. We show that by taking into account recent constraints on the density derivative of the symmetry energy and the theoretical and experimental results on the excitations of delta isobars in nuclei, delta isobars are necessary ingredients for the equations of state used for studying neutron stars. We analyze the effect of the appearance of deltas on the structure of neutron stars: as in the case of hyperons, matter containing delta is too soft for allowing the existence of 2M⊙ neutron stars. Quark stars on the other hand, could reach very massive configurations and they could form from a process of conversion of hadronic stars in which an initial seed of strangeness appears through hyperons.
© Owned by the authors, published by EDP Sciences, 2015
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