二倍太阳质量中子星的计算研究二倍太阳质量中子星的计算研究 赵先锋赵先锋滁州学院滁州学院机械与电子工程学院机械与电子工程学院8/25/20248/25/2024 Main Content, Introduction, The RMF theory and the mass of a neutron star, Approximate limitation of the hyperon coupling constantsn Four of the possible models for the neutron star PSR J1614-2230, Summary8/25/20242 Ⅰ. Introduction1. The discovery of the two-times solar mass neutron star PSR J1614-2230 The neutron star PSR J1614-2230, which mass is 1.97 M⊙ and may be the heaviest by now, was observed in 2010. Obviously, it will be meaningful to describe its mass theoretically.8/25/20243 Based on EOS-independent analytic solutions of Einstein’s equations, Demorest et al calculated the mass of the neutron star and found that the calculations, which is in the hadronic level, can not obtain the mass of the neutron star PSR J1614-2230 because of its too smaller mass. But we think that this may be questionable.2. In the hadronic level, the mass of neutron star 1.97 M ⊙ ⊙ can be obtained if the suitable EOS and the coupling constants are chosen8/25/20244 1985, considering the octet, the mass of neutron star calculated by Glendenning is in the range of 1.5~1.8 M⊙ in the framework of relativistic mean field (RMF) theory. But if only nucleons being included in the neutron star, the mass of neutron star he obtained would be 2.36 M⊙. It is obvious that considering the hyperons within neutron star would reduce the mass.8/25/20245 Calculations show that the neutron-star mass is very sensitive to the hyperon coupling constants. One of the parameter selection methods is to choose the coupling constants of meson ω by the constituent quark model [SU(6) symmetry] and to choose the couplings constants of meson σ by fitting the Λ,Σ and Ξ well depth in nuclear matter. Because the energy density of neutron star matter is several times larger than the saturation nucleon density, the prior parameter selection methods to a great extent is extrapolative.n In the interior of a neutron star, the hyperons would be produced with the baryon number density increase. So it is reasonable to think that neutron stars containing hyperons.8/25/20246 n From the results above it can be seen that, considering nucleons within neutron stars, the mass of neutron star which is greater than 1.97 M⊙ may be obtained if the suitable EOS and the coupling constants are chosen.n In this work, we apply the RMF theory to describe the mass of the neutron star PSR J1614-2230 by adjusting the hyperon coupling constants.8/25/20247 The Lagrangian density of hadron matter reads as follows Ⅱ.The RMF theory and the mass of a neutron star8/25/20248 The energy density and pressure of a neutron star are given by8/25/20249 where, m* is the effective mass of baryonsWe use the O-V equation to obtain the mass and the radius of neutron stars8/25/202410 Ⅲ. Approximate limitation of the hyperon coupling constantsnIn this work, we choose the GL97 set listed in Table Ⅰ.We define the ratios8/25/202411 8/25/202412 8/25/202413 8/25/202414 8/25/202415 8/25/202416 Ⅳ. Four of the possible models for the neutron star PSR J1614-22308/25/202417 8/25/202418 8/25/202419 8/25/202420 Ⅴ. Summary8/25/202421 8/25/202422 Thank you very much!8/25/202423 。