Searching for isovector signatures in the neutron-rich oxygen and calcium isotopes

Autor: Wei-Chia Chen, J. Piekarewicz
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Zdroj: Physics Letters B, Vol 748, Iss C, Pp 284-288 (2015)
Druh dokumentu: article
ISSN: 0370-2693
1873-2445
DOI: 10.1016/j.physletb.2015.07.020
Popis: We search for potential isovector signatures in the neutron-rich oxygen and calcium isotopes within the framework of a relativistic mean-field theory with an exact treatment of pairing correlations. To probe the isovector sector we calibrate a few relativistic density functionals using the same isoscalar constraints but with one differing isovector assumption. It is found that under certain conditions, the isotopic chain in oxygen can be made to terminate at the experimentally observed 24O isotope and in the case of the calcium isotopes at 60Ca. To produce such behavior, the resulting symmetry energy must be soft, with predicted values for the symmetry energy and its slope at saturation density being J=(30.92±0.47) MeV and L=(51.0±1.5) MeV, respectively. As a consequence, the neutron-skin thickness of 208Pb is rather small: Rskin208=(0.161±0.011) fm. This same model—labeled “FSUGarnet”—predicts R1.4=(13.0±0.1) km for the radius of a “canonical” 1.4M⊙ neutron star, yet is also able to support a two-solar-mass neutron star.
Databáze: Directory of Open Access Journals
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