Phenomenological QCD equations of state for neutron stars

Toru Kojo; Philip D. Powell; Yifan Song; Gordon Baym

doi:10.1016/j.nuclphysa.2016.02.008

Phenomenological QCD equations of state for neutron stars

Toru Kojo, Philip D. Powell, Yifan Song, Gordon Baym

Research output: Contribution to journal › Article › peer-review

14 Citations (Scopus)

Abstract

We delineate the properties of QCD matter at baryon density n_B=1−10n₀ (n₀: nuclear saturation density), through the construction of neutron star equations of state that satisfy the neutron star mass-radius constraints as well as physical conditions on the speed of sound. The QCD matter is described in the 3-window modeling: at n_B≲2n₀ purely nuclear matter; at n_B≳5n₀ percolated quark matter; and at 2n₀≲n_B≲5n₀ matter intermediate between these two which are constructed by interpolation. Using a schematic quark model with effective interactions inspired from hadron and nuclear physics, we analyze the strength of interactions necessary to describe observed neutron star properties. Our finding is that the interactions should remain as strong as in the QCD vacuum, indicating that gluons at n_B=1−10n₀ remain non-perturbative even after quark matter formation.

Original language	English
Pages (from-to)	821-825
Number of pages	5
Journal	Nuclear Physics A
Volume	956
DOIs	https://doi.org/10.1016/j.nuclphysa.2016.02.008
Publication status	Published - 2016 Dec 1
Externally published	Yes

Keywords

Neutron stars
QCD equations of state

ASJC Scopus subject areas

Nuclear and High Energy Physics

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10.1016/j.nuclphysa.2016.02.008

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@article{64c5e3a3a99c453485d73e1c318b5fc1,

title = "Phenomenological QCD equations of state for neutron stars",

abstract = "We delineate the properties of QCD matter at baryon density nB=1−10n0 (n0: nuclear saturation density), through the construction of neutron star equations of state that satisfy the neutron star mass-radius constraints as well as physical conditions on the speed of sound. The QCD matter is described in the 3-window modeling: at nB≲2n0 purely nuclear matter; at nB≳5n0 percolated quark matter; and at 2n0≲nB≲5n0 matter intermediate between these two which are constructed by interpolation. Using a schematic quark model with effective interactions inspired from hadron and nuclear physics, we analyze the strength of interactions necessary to describe observed neutron star properties. Our finding is that the interactions should remain as strong as in the QCD vacuum, indicating that gluons at nB=1−10n0 remain non-perturbative even after quark matter formation.",

keywords = "Neutron stars, QCD equations of state",

author = "Toru Kojo and Powell, {Philip D.} and Yifan Song and Gordon Baym",

note = "Funding Information: T.K. thanks Kenji Fukushima for his collaborative work [15] which sharpened ideas about the medium couplings in effective models. This work was supported in part by NSF Grants PHY09-69790 and PHY13-05891. Publisher Copyright: {\textcopyright} 2016 Elsevier B.V.",

year = "2016",

month = dec,

day = "1",

doi = "10.1016/j.nuclphysa.2016.02.008",

language = "English",

volume = "956",

pages = "821--825",

journal = "Nuclear Physics A",

issn = "0375-9474",

publisher = "Elsevier",

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TY - JOUR

T1 - Phenomenological QCD equations of state for neutron stars

AU - Kojo, Toru

AU - Powell, Philip D.

AU - Song, Yifan

AU - Baym, Gordon

N1 - Funding Information: T.K. thanks Kenji Fukushima for his collaborative work [15] which sharpened ideas about the medium couplings in effective models. This work was supported in part by NSF Grants PHY09-69790 and PHY13-05891. Publisher Copyright: © 2016 Elsevier B.V.

PY - 2016/12/1

Y1 - 2016/12/1

N2 - We delineate the properties of QCD matter at baryon density nB=1−10n0 (n0: nuclear saturation density), through the construction of neutron star equations of state that satisfy the neutron star mass-radius constraints as well as physical conditions on the speed of sound. The QCD matter is described in the 3-window modeling: at nB≲2n0 purely nuclear matter; at nB≳5n0 percolated quark matter; and at 2n0≲nB≲5n0 matter intermediate between these two which are constructed by interpolation. Using a schematic quark model with effective interactions inspired from hadron and nuclear physics, we analyze the strength of interactions necessary to describe observed neutron star properties. Our finding is that the interactions should remain as strong as in the QCD vacuum, indicating that gluons at nB=1−10n0 remain non-perturbative even after quark matter formation.

AB - We delineate the properties of QCD matter at baryon density nB=1−10n0 (n0: nuclear saturation density), through the construction of neutron star equations of state that satisfy the neutron star mass-radius constraints as well as physical conditions on the speed of sound. The QCD matter is described in the 3-window modeling: at nB≲2n0 purely nuclear matter; at nB≳5n0 percolated quark matter; and at 2n0≲nB≲5n0 matter intermediate between these two which are constructed by interpolation. Using a schematic quark model with effective interactions inspired from hadron and nuclear physics, we analyze the strength of interactions necessary to describe observed neutron star properties. Our finding is that the interactions should remain as strong as in the QCD vacuum, indicating that gluons at nB=1−10n0 remain non-perturbative even after quark matter formation.

KW - Neutron stars

KW - QCD equations of state

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U2 - 10.1016/j.nuclphysa.2016.02.008

DO - 10.1016/j.nuclphysa.2016.02.008

M3 - Article

AN - SCOPUS:84991773712

SN - 0375-9474

VL - 956

SP - 821

EP - 825

JO - Nuclear Physics A

JF - Nuclear Physics A

ER -

Phenomenological QCD equations of state for neutron stars

Abstract

Keywords

ASJC Scopus subject areas

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