Neutron star structure in an in-medium modified chiral soliton model

We study the internal structure of a static and spherically symmetric neutron star in the framework of an in-medium modified chiral soliton model. The Equations of State describing an infinite and asymmetric nuclear matter are obtained introducing the density dependent functions into the low energy free space Lagrangian of the model starting from the phenomenology of pionic atoms. The parametrizations of density dependent functions are related to the properties of isospin asymmetric nuclear systems at saturation density of symmetric nuclear matter $\rho_0\simeq 0.16$~fm$^{-3}$. Our results, corresponding to the compressibility of symmetric nuclear matter in the range 250\,\mbox{MeV}\le K_0\le 270\,\mbox{MeV} and the slop parameter value of symmetry energy in the range 30\,\mbox{MeV}\le L_S\le 50\,\mbox{MeV}, are consistent with the results from other approaches and with the experimental indications. Using the modified Equations of State, near the saturation density of symmetric nuclear matter $\rho_0$, the extrapolations to the high density and highly isospin asymmetric regions have been performed. The calculations showed that the properties of $\sim 1.4M_\odot$ and $\sim 2M_\odot$ neutron stars can be well reproduced in the framework of present approach.Comment: 9 pages, 5 figures, 3 table

Mesons and nucleons from holographic QCD

We present in this talk a recent investigation on a unified approach within the framework of a hard-wall model of AdS/QCD. We first study a theoretical inconsistency in existing models. In order to remove this inconsistency, we propose a unified approach in which the mesons and the nucleons are treated on the same footing, the same infrared (IR) cutoff being employed in both fermionic and bosonic sectors. We also suggest a possible way of improving the model by introducing a five-dimensional anomalous dimension.Comment: 10 pages, 2 figures. A talk give at the Workshop on "Hadron and Nuclear Physics (HNP09)" Nov. 16-19, 2009, RCNP, Osaka Universit