Quark star phenomenology

Freedman, Barry; McLerran, Larry

doi:10.1103/physrevd.17.1109

Cited by 225 publications

(164 citation statements)

References 28 publications

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“…The numerical results depend on the choice of renormalization, but qualitatively similar results are found for other choices of σ, including the original [14] (but physically questionable [4]) choice of σ = m s . A perturbative expansion to first order in α S is unreliable at high α S .…”

supporting

confidence: 60%

Intermediate Mass Strangelets are Positively Charged

2000

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For a limited range of parameters, stable strange quark matter may be negatively charged in bulk due to one gluon exchange interactions. However, the reduction in strange quark occupation in the surface layer, which is responsible for surface tension, more than compensates this for intermediate mass strangelets, which therefore always have positive quark charge (e.g. for baryon number between 10 2 and 10 18 assuming αS = 0.9). While details are sensitive to the choice of renormalization, the general conclusion is not. This rules out a scenario where negatively charged strangelets produced in ultrarelativistic heavy ion colliders might grow indefinitely with potentially disastrous consequences.12.38. Mh, 12.39.Ba, 24.85.+p, There has recently been some concern about the possibility that a negatively charged strangelet formed in ultrarelativistic heavy ion collisions might grow by absorbing nuclei to, in principle, swallow the Earth. Two investigations have described a number of reasons, theoretical as well as experimental, why such a scenario is exceedingly unlikely [1].Many unlikely coincidences are required for a dangerous situation to develop. Positively charged quark matter repels ordinary nuclei, so at the very least, the small strangelets (baryon number A ≪ 4 × 10 2 , where 4 × 10 2 is the total number of nucleons involved in a collision of two gold or lead nuclei) hypothetically formed in ultrarelativistic heavy ion collisions must have negative quark charge. And for growth to proceed, not only must the ultimate state of stable bulk strange quark matter be negatively charged, but so must the path of intermediate mass strangelets all the way from low A to A → ∞.The present study demonstrates, that even in the unlikely case where bulk strange quark matter is both stable and has negative quark charge, and where a long-lived, negatively charged strangelet is formed in a collision, such a strangelet cannot grow significantly by absorbing nuclei. The reason is, that the quark charge of intermediate mass strangelets near the lowest energy state is always positive regardless of the bulk charge. Thus the potentially dangerous strangelet growth path is blocked by Coulomb repulsion.Following the original suggestions of Bodmer [2] and Witten [3], Farhi and Jaffe [4] presented a detailed study of strange quark matter properties in bulk, as well as finite size strangelets. Concerning the issue of the electric charge of bulk strange matter they showed, that the quark charge of stable strange matter is always positive for small strong interaction constant, α S [5]. This is easy to understand physically, because of the fortuitous cancellation of charge for a gas with equal numbers of up, down and strange quarks. For finite strange quark mass and up and down quark masses close to zero, the number of s-quarks will be reduced, and the net quark charge be positive, even though the actual numbers are small, with a typical charge-to-baryon number ratio of 10 −3 -10 −7 . One gluon exchange interactions are repulsive for massless ...

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confidence: 60%

Intermediate Mass Strangelets are Positively Charged

2000

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“…In general we can certainly write 1) and separate the expectation value of the stress-energy-momentum tensor into a contribution from some suitably chosen vacuum state, plus a contribution from the excitations above that vacuum state. For instance, for an uncollapsed star…”

Section: Introductionmentioning

confidence: 99%

Small, dark, and heavy: But is it a black hole?

Visser

Barceló²,

Liberati³

et al. 2009

Proceedings of Black Holes in General Relativity and String Theory — PoS(BHs, GR and Strings)

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“…neutron stars with a quark matter core. In this model quark matter is treated as a free relativistic Fermi gas of u, d and s quarks, which reside in a region characterized by a constant energy density B, with at most perturbative corrections up to the second order in the QCD structure constant α s [28][29][30]. The parameter B takes into account, in a crude phenomenological manner, nonperturbative aspects of QCD and it is related to the bag constant which in the MIT bag model [22] gives the confinement of quarks within hadrons.…”

Section: Introductionmentioning

confidence: 99%

Quark deconfinement transition in neutron stars with the field correlator method

Logoteta

Bombaci

2013

Phys. Rev. D

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A phase of strong interacting matter with deconfined quarks is expected in the core of massive neutron stars. In this article, we perform a study of the hadron-quark phase transition in cold (T = 0) neutron star matter and we calculate various structural properties of hybrid stars. For the quark phase, we make use of an equation of state (EOS) derived with the field correlator method (FCM) recently extended to the case of nonzero baryon density. For the hadronic phase, we consider both pure nucleonic and hyperonic matter, and we derive the corresponding EOS within a relativistic mean field approach. We make use of measured neutron star masses, and particularly the mass M = 1.97 ± 0.04 M of PSR J1614-2230 to constrain the values of the gluon condensate G2, which is one of the EOS parameters within the FCM. We find that the values of G2 extracted from the mass measurement of PSR J1614-2230 are consistent with the values of the same quantity derived within the FCM from recent lattice QCD calculations of the deconfinement transition temperature at zero baryon chemical potential. The FCM thus provides a powerful tool to link numerical calculations of QCD on a space-time lattice with measured neutron star masses. --------------------

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Quark star phenomenology

Cited by 225 publications

References 28 publications

Intermediate Mass Strangelets are Positively Charged

Intermediate Mass Strangelets are Positively Charged

Small, dark, and heavy: But is it a black hole?

Quark deconfinement transition in neutron stars with the field correlator method

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