Searching for isovector signatures in the neutron-rich oxygen and calcium isotopes
Searching for isovector signatures in the neutron-rich oxygen and calcium isotopes
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DOI：
10.1016/j.physletb.2015.07.020
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发表时间：
2015-09-02
影响因子：
4.4
通讯作者：
Piekarewicz, J.
中科院分区：
文献类型：
--
作者：
Chen, Wei-Chia;Piekarewicz, J.
我们在相对论平均场理论的框架内寻找富中子氧和钙同位素中潜在的等向量特征，并精确处理配对相关性。为了探测等向量扇区，我们使用相同的等标量约束但使用一种不同的等向量假设来校准一些相对论密度泛函。研究发现，在某些条件下，氧中的同位素链可以终止于实验观察到的 O-24 同位素，而钙同位素则终止于 Ca-60。为了产生这种行为，产生的对称能量必须是软的，对称能量的预测值及其在饱和密度下的斜率分别为 J = (30.92 +/- 0.47) MeV 和 L = (51.0 +/- 1.5) MeV。因此，Pb-208 的中子皮厚度相当小：R-皮(208) = (0.161 +/- 0.011) fm。这个标有“FSUGarnet”的模型预测“规范”1.4M（圆点）中子星的半径为 R-1.4 = (13.0 +/- 0.1) km，但也能够支持两个太阳质量的中子星。 (C) 2015 年作者。由 Elsevier B.V. 出版
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 O-24 isotope and in the case of the calcium isotopes at Ca-60. 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 Pb-208 is rather small: R-skin(208) = (0.161 +/- 0.011) fm. This same model-labeled "FSUGarnet"-predicts R-1.4 = (13.0 +/- 0.1) km for the radius of a "canonical" 1.4M(circle dot) neutron star, yet is also able to support a two-solar-mass neutron star. (C) 2015 The Authors. Published by Elsevier B.V.