ARE NEUTRON-RICH ELEMENTS PRODUCED IN THE COLLAPSE OF STRANGE DWARFS?

2006 ◽  
Vol 15 (02) ◽  
pp. 153-163 ◽  
Author(s):  
G. F. MARRANGHELLO ◽  
J. A. DE FREITAS PACHECO
Keyword(s):  
Strange Quark ◽  
Critical Mass ◽  
Chemical Yield ◽  
Strange Quark Matter ◽  
Hadronic Matter ◽  
Hybrid Star ◽  
Baryonic Number ◽  
The Galaxy ◽  
Strange Dwarfs ◽  
Hybrid Stars

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.

scholarly journals Strange matter in compact stars

2018 ◽  
Vol 171 ◽  
pp. 08001 ◽  
Author(s):  
Thomas Klähn ◽  
David B. Blaschke
Keyword(s):  
Quark Matter ◽  
Strange Quark ◽  
Chiral Symmetry Breaking ◽  
Dense Matter ◽  
Strange Quark Matter ◽  
Compact Stars ◽  
Hadronic Matter ◽  
Model Description ◽  
Severe Problem ◽  
Strange Matter

We discuss possible scenarios for the existence of strange matter in compact stars. The appearance of hyperons leads to a hyperon puzzle in ab-initio approaches based on effective baryon-baryon potentials but is not a severe problem in relativistic mean field models. In general, the puzzle can be resolved in a natural way if hadronic matter gets stiffened at supersaturation densities, an effect based on the quark Pauli quenching between hadrons. We explain the conflict between the necessity to implement dynamical chiral symmetry breaking into a model description and the conditions for the appearance of absolutely stable strange quark matter that require both, approximately masslessness of quarks and a mechanism of confinement. The role of strangeness in compact stars (hadronic or quark matter realizations) remains unsettled. It is not excluded that strangeness plays no role in compact stars at all. To answer the question whether the case of absolutely stable strange quark matter can be excluded on theoretical grounds requires an understanding of dense matter that we have not yet reached.

scholarly journals Neutron Stars, Strange Pulsars and Strange Dwarfs

1996 ◽  
Vol 160 ◽  
pp. 135-136
Author(s):  
Fridolin Weber ◽  
Norman K. Glendenning
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Strong Interaction ◽  
Ground State ◽  
Strange Quark ◽  
Complete Sequence ◽  
Strange Quark Matter ◽  
Compact Stars ◽  
Strange Dwarfs ◽  
Separate Class

The hypothesis that strange quark matter may be the absolute ground state of the strong interaction (not56Fe) has been raised independently by Boder and Witten. If the hypothesis is true, then a separate class of compact stars could exist, which are calledstrange matter stars. The properties of the complete sequence of such stars, which range from compact neutron-star-like strange stars to strange dwarfs to strange planets. The latter two constitute the strange counterparts of ordinary white dwarfs and planets, respectively. The properties of these objects are discussed in this paper.

HYBRID STARS WITH DELTA MATTER AND COLOR–FLAVOR LOCKED QUARK PHASE

2008 ◽  
Vol 17 (05) ◽  
pp. 737-746 ◽  
Author(s):  
H. RODRIGUES ◽  
J. C. T. OLIVEIRA ◽  
S. B. DUARTE
Keyword(s):  
Phase Transition ◽  
Quark Matter ◽  
Strange Quark ◽  
Bose Condensate ◽  
Hadronic Matter ◽  
Hybrid Stars ◽  
S Quarks ◽  
Quark Phase ◽  
Color Superconductor

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.

PHYSICS OF STRANGE MATTER FOR RELATIVISTIC HEAVY-ION COLLISIONS

1996 ◽  
Vol 05 (02) ◽  
pp. 239-300 ◽  
Author(s):  
CARSTEN GREINER ◽  
JÜRGEN SCHAFFNER
Keyword(s):  
Heavy Ion Collisions ◽  
Strange Quark ◽  
Baryon Number ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Strange Quark Matter ◽  
Hadronic Matter ◽  
Relativistic Heavy Ion Collisions ◽  
Stable States ◽  
Ion Collisions

Relativistic heavy-ion collisions offer the possibility to produce exotic metastable or even absolutely stable states of nuclear matter containing (roughly) equal number of strangeness compared to the baryon number: Strangelets, small pieces of strange quark matter, were proposed as a signal of quark-gluon plasma formation. As their hadronic counterpart, also small pieces of strange hadronic matter may also show up with rather similar properties. The reasoning of both their stability and existence, the possible separation of strangeness necessary for their formation, and the chances for their detection, are reviewed.

scholarly journals Simplified Thermal Evolution of Proto-Hybrid Stars

2017 ◽  
Vol 45 ◽  
pp. 1760041 ◽  
Author(s):  
Mauro Mariani ◽  
Milva Orsaria ◽  
Héctor Vucetich
Keyword(s):  
Phase Transition ◽  
Neutron Stars ◽  
Thermal Evolution ◽  
Late Phase ◽  
Hadronic Matter ◽  
Maximum Mass ◽  
Hybrid Star ◽  
Star Evolution ◽  
Hybrid Stars ◽  
Quark Phase

We study the possibility of a hadron-quark phase transition in the interior of neutron stars, taking into account different schematic evolutionary stages at finite temperature. Furthermore, we analyze the astrophysical properties of hot and cold hybrid stars, considering the constraint on maximum mass given by the pulsars J1614-2230 and J1614-2230. We obtain cold hybrid stars with maximum masses [Formula: see text] M[Formula: see text]. Our study also suggest that during the proto-hybrid star evolution a late phase transition between hadronic matter and quark matter could occur, in contrast with previous studies of proto-neutron stars.

scholarly journals GAPLESS COLOR–FLAVOR LOCKED PHASE IN QUARK AND HYBRID STARS

2006 ◽  
Vol 15 (09) ◽  
pp. 1515-1529 ◽  
Author(s):  
A. LAVAGNO ◽  
G. PAGLIARA
Keyword(s):  
Quark Mass ◽  
Strange Quark ◽  
Chemical Potential ◽  
Compact Star ◽  
Superconducting Phase ◽  
Compact Stars ◽  
Hadronic Matter ◽  
Strange Quark Mass ◽  
Baryonic Chemical Potential ◽  
Hybrid Stars

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.

Strange Quark Matter as Dark Matter

2019 ◽  
Vol 22 (4) ◽  
pp. 311-317
Author(s):  
Hidezumi Terazawa
Keyword(s):  
Dark Matter ◽  
Quark Matter ◽  
Strange Quark ◽  
Strange Quark Matter ◽  
Quark Stars

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).

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