Versatility of field theory motivated nuclear effective Lagrangian approach

Abstract

We analyze the results for infinite nuclear and neutron matter using the standard relativistic mean field model and its recent effective field theory motivated generalization. For the first time, we show quantitatively that the inclusion in the effective theory of vector meson self-interactions and scalar-vector cross-interactions explains naturally the recent experimental observations of the softness of the nuclear equation of state, without losing the advantages of the standard relativistic model for finite nuclei.

Neutron star matter in an effective model

“…Non-relativistic [5,6] and relativistic models ( [7]- [10]) predict nearly same maximum mass of neutron star. Relativistic models have been successfully applied to study finite nuclei [11] and infinite nuclear matter [12] where they not only satisfy the properties of nuclear matter at saturation but also the extrapolation to high density is automatically causal. Field theories such as the non-linear σ−ω model [13] have been phenomenal in this respect.…”

The attribute of rotational profile to the hyperon puzzle in the prediction of heaviest compact star

“…Nowadays, the mean field treatment of QHD has been used widely to describe the properties of infinite nuclear matter 76,[87][88][89] and finite nuclei. [90][91][92][93][97][98][99] In this theory, the nucleons are considered as Dirac particle, interact through the exchange of various mesons (i.e., iso-scalar scalar σ-, iso-scalar vector ω-, iso-vector-vector ρ-and iso-vector-scalar δ-mesons).…”

“…Reviewing the works concerning the rapidly rotating stars in general relativity, there are few pioneering predictions, which have been observed by considering some of the sophisticated aspects of the neutron star: the nuclear equation Besides, the calculation performed by including the ω-ρ cross-coupling and quartic terms in the RMF softens the EoS to good agreement with the recent observed mass of compact stars. [76][77][78][79] In addition to that, the generalized model having the low lying octet of baryons makes it difficult to obtain a neutron star mass greater than 2.0M . 43,44,77,79 In continuation of our earlier work, 79 we here analyze the rotational attributes of neutron star with various hyperon-meson couplings within the framework of effective field theory motivated relativistic mean field model (E-RMF).…”

“…43,44,77,79 In continuation of our earlier work, 79 we here analyze the rotational attributes of neutron star with various hyperon-meson couplings within the framework of effective field theory motivated relativistic mean field model (E-RMF). 43,76,79,80 The degrees of freedom in this theory are nucleons interacting through the exchange of iso-scalar scalar σ−, iso-scalar vector ω−, and iso-vector-vector ρ− meson fields. The chiral effective Lagrangian (i.e., the E-RMF formalism) 37,76,[80][81][82][83][84][85][86][87][88] is the extension of the standard relativistic mean-field (RMF) theory 28,36,[89][90][91][92][93][94][95][96] with the addition of nonlinear scalar-vector and vector-vector selfinteraction, applying the naive dimensional analysis and the concept of naturalness at a given level of accuracy.…”

“…The chiral effective Lagrangian (i.e., the E-RMF formalism) 37,76,[80][81][82][83][84][85][86][87][88] is the extension of the standard relativistic mean-field (RMF) theory 28,36,[89][90][91][92][93][94][95][96] with the addition of nonlinear scalar-vector and vector-vector selfinteraction, applying the naive dimensional analysis and the concept of naturalness at a given level of accuracy. 37,76,80,81,[85][86][87][88] In particular, the motivation behind the present work is to investigate the axisymmetric hydrostatic equilibria of rotating neutron star and the effects of rotational profiles in the hyperon matter under β-equilibrium condition at high density. In other words, this present work will provide a relativistic mean field descriptions of the static and rotating (sub-millisecond to super-millisecond) compact star properties for various hyperon-meson couplings.…”