Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2011-11-29
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
7 pages, 5 figures. Main results of this paper were already presented at the MODE-SNR-PWN Workshop in Bordeaux, France, Novemb
Scientific paper
Recent measurement of mass of PSR J1614-2230 rules out most of existing models of equation of state (EOS) of dense matter with high-density softening due to hyperonization or a phase transition to quark matter or a boson condensate. We look for a solution of an apparent contradiction between the consequences stemming from up-to-date hypernuclear data, indicating appearance of hyperons at 3 nuclear densities and existence of a two-solar-mass neutron star. We consider a non-linear relativistic mean field (RMF) model involving baryon octet coupled to meson fields. An effective lagrangian includes quartic terms in the meson fields. The values of the parameters of the model are obtained by fitting semi-empirical parameters of nuclear matter at the saturation point, as well as potential wells for hyperons in nuclear matter and the strength of the Lambda-Lambda attraction in double-Lambda hypernuclei. We propose a non-linear RMF model which is consistent with up-to-date semiempirical nuclear and hypernuclear data and allows for neutron stars with hyperon cores and M larger than 2 solar masses. The model involves hidden-strangenes scalar and vector mesons, coupled to hyperons only, and quartic terms involving vector meson fields. Our EOS involving hyperons is stiffer than the corresponding nucleonic EOS (with hyperons artificially suppressed) above five nuclear densities. Required stiffening is generated by the quartic terms involving hidden-strangeness vector meson.
Bednarek Ilona
Bejger Michal
Haensel Pawel
Mańka Ryszard
Zdunik Leszek J.
No associations
LandOfFree
Hyperons in neutron-star cores and two-solar-mass pulsar does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Hyperons in neutron-star cores and two-solar-mass pulsar, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hyperons in neutron-star cores and two-solar-mass pulsar will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-17114