scholarly journals Hybrid stars with large strange quark cores constrained by GW170817

2021 ◽  
Vol 103 (12) ◽  
Author(s):  
Márcio Ferreira ◽  
Renan Câmara Pereira ◽  
Constança Providência
Keyword(s):  
2008 ◽  
Vol 17 (05) ◽  
pp. 737-746 ◽  
Author(s):  
H. RODRIGUES ◽  
J. C. T. OLIVEIRA ◽  
S. B. DUARTE

The color–flavor locked (CFL) phase is believed to be the fundamental state of strange quark matter (SQM) at high densities. The CFL phase is a color superconductor composed of pairs of u, d and s quarks, with no electrons, forming a Bose condensate. In this work, we analyze a possible phase transition of hadronic matter made of nucleons, Δ–resonances, hyperons and leptons, to CFL superconducting quark matter. An equation of state taking into account this phase transition is employed to determine the characteristics of a hybrid star. The role of the color superconducting gap on the hybrid stars properties is also discussed.


2006 ◽  
Vol 15 (02) ◽  
pp. 153-163 ◽  
Author(s):  
G. F. MARRANGHELLO ◽  
J. A. DE FREITAS PACHECO

The structure of strange dwarfs and that of hybrid stars with the same baryonic number is compared. There is a critical mass (M ≈ 0.24M⊙) in the strange dwarf branch, below which configurations with the same baryonic number in the hybrid star branch are more stable. If a transition occurs between both branches, the collapse releases an energy of about of 3 × 1050 erg , mostly in the form of neutrinos resulting from the conversion of hadronic matter onto strange quark matter. Only a fraction (~ 4%) is required to expel the outer neutron-rich layers. These events may contribute significantly to the chemical yield of nuclides with A ≥ 80 in the Galaxy, if their frequency is of about one per 1,500 years.


2018 ◽  
Vol 27 (01) ◽  
pp. 1850006 ◽  
Author(s):  
Jian-Feng Xu ◽  
Yan-An Luo ◽  
Lei Li ◽  
Guang-Xiong Peng

We study the strange quark mass effect on the phase diagram of strong interaction and the structure of compact stars with a thermodynamically enhanced perturbative QCD model by matching quark matter onto nuclear matter using the Gibbs conditions. It is found that the mass effect of strange quark matter can obviously stiffen the equation of state of mixed phases and result in more massive hybrid stars (HSs), while that usually lowers the maximum mass of pure quark stars. Given reasonable model parameters, the maximum mass of HSs can reach two times the solar mass and the stars always have mixed-phase core in a considerably wide range of model parameters.


2006 ◽  
Vol 15 (09) ◽  
pp. 1515-1529 ◽  
Author(s):  
A. LAVAGNO ◽  
G. PAGLIARA

We study the effects of the gapless color–flavor locked (gCFL) phase on the equation of state of strongly interacting matter in the range of baryonic chemical potential involved in a compact star. We analyze the possibility of a phase transition from hadronic matter to gCFL quark matter and we discuss, for different values of the strange quark mass and diquark coupling strength, the existence of a gCFL phase in quark or hybrid stars. The mass–radius relation and the structure of compact stars containing the gCFL phase are shown and the physical relevance of this superconducting phase inside a stellar object is also discussed.


2019 ◽  
Vol 22 (4) ◽  
pp. 311-317
Author(s):  
Hidezumi Terazawa

New forms of matter such as super-hypernuclei (strange quark matter) and superhypernuclear stars (strange quark stars) as candidates for dark matter are discussed in some detail, based on the so-called "Bodmer–Terazawa–Witten hypothesis" assuming that they are stable absolutely or quasi-stable (decaying only weakly).


2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Jason Aebischer ◽  
Benjamín Grinstein

Abstract Applying an operator product expansion approach we update the Standard Model prediction of the Bc lifetime from over 20 years ago. The non-perturbative velocity expansion is carried out up to third order in the relative velocity of the heavy quarks. The scheme dependence is studied using three different mass schemes for the $$ \overline{b} $$ b ¯ and c quarks, resulting in three different values consistent with each other and with experiment. Special focus has been laid on renormalon cancellation in the computation. Uncertainties resulting from scale dependence, neglecting the strange quark mass, non-perturbative matrix elements and parametric uncertainties are discussed in detail. The resulting uncertainties are still rather large compared to the experimental ones, and therefore do not allow for clear-cut conclusions concerning New Physics effects in the Bc decay.


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