Solitons in nonlocal chiral quark models

Broniowski, Wojciech; Golli, B.; Ripka, G.

doi:10.1016/s0375-9474(01)01670-0

Cited by 41 publications

(35 citation statements)

References 65 publications

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“…The non-local character of the interactions arises naturally in the context of several successful approaches to low-energy quark dynamics, and leads to a momentum dependence in the quark propagator that can be made consistent [16] with lattice results. It has been shown [17][18][19][20] that non-local models …”

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confidence: 99%

Deconfinement and chiral restoration in non-local PNJL models at zero and imaginary chemical potential

2012

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We study the deconfinement and chiral restoration transitions in the context of non-local PNJL models, considering the impact of the presence of dynamical quarks on the scale parameter appearing in the Polyakov potential. We show that the corresponding critical temperatures are naturally entangled for both zero and imaginary chemical potential, in good agreement with lattice QCD results. We also analyze the Roberge Weiss transition, which is found to be first order at the associated endpoint.PACS numbers: 12.39. Ki, 11.30.Rd, 12.38.Mh The detailed understanding of the behavior of strongly interacting matter at finite temperature and baryon density represents an issue of great interest in particle physics [1]. From the theoretical point of view, this problem can be addressed through lattice QCD calculations [2-4], which have been significantly improved in the last years. However, this ab initio approach is not yet able to provide a full understanding of the QCD phase diagram. One well-known difficulty is given by the so-called sign problem, which arises when dealing with finite real chemical potentials. Thus, it is worth to develop alternative approaches, such as the study of effective models that show consistency with lattice QCD results and can be extrapolated into regions not accessible by lattice techniques.One of these effective theories, proposed quite recently, is the so-called Polyakov-Nambu-JonaLasinio (PNJL) model [5][6][7][8][9][10][11], an extension of the well-known NJL model [12] in which quarks are coupled to the Polyakov loop (PL), providing a common framework to study both the chiral and deconfinement transitions. As a further improvement over the (local) PNJL model, extensions that include covariant non-local quark interactions have also been considered [13][14][15]. The non-local character of the interactions arises naturally in the context of several successful approaches to low-energy quark dynamics, and leads to a momentum dependence in the quark propagator that can be made consistent [16] with lattice results. It has been shown [17][18][19][20] that non-local models

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Deconfinement and chiral restoration in non-local PNJL models at zero and imaginary chemical potential

2012

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“…On the other hand, the inclusion of meson self-interaction which allows for a substantial deviation of the σ-field from its vacuum value inside the baryon considerably increases C A 5 . The LSM overestimates this contribution, but this is not the case in other chiral models which allow for a non-zero fluctuation of the σ-field; in a version of the NJL model with nonlocal regulators [13] the contribution of sea quarks to the nucleon g A is more than a factor of two weaker than the equivalent contribution of chiral mesons in the LSM.…”

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confidence: 90%

Axial Excitation of the Δ in Chiral Quark Models

Širca

Amoreira

Fiolhais

et al. 2003

Few-Body Problems in Physics ’02

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“…For fixed values of the temperature T and the chemical potential µ, the mean field valuesσ and∆, as well as the chemical potentials µ e and µ 8 , can be numerically obtained from the gap equations (13), together with the neutron star constraints (18) and (19). Let us begin by considering the case H/G = 0.75, which is motivated by various effective models of quark-quark interactions.…”

Section: B Order Parameters and Phase Transitionsmentioning

confidence: 99%

“…Indeed, nonlocal interactions regularize the models in such a way that anomalies are preserved [13] and charges properly quantized, the effective interaction is finite to all orders in the loop expansion and there is no need to introduce extra cut-offs, soft regulators lead to small nextto-leading order corrections [14], etc. This type of models has been successfully used to investigate meson [15][16][17][18] and baryon [19] properties at vanishing temperature and chemical potential, and the phase diagram of isospin symmetric matter has also been studied within this context [20][21][22][23]. Now our aim is to extend these analyses to the case in which compact star conditions are imposed.…”

Section: Introductionmentioning

confidence: 99%

Phase diagram of quark matter in nonlocal chiral models under color and electric charge neutrality conditions

Dumm¹,

Grunfeld²,

Scoccola³

2007

Braz. J. Phys.

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We consider the phase diagram of two-flavor quark matter under neutron star constraints for the case of two nonlocal, covariant quark models within the mean field approximation. In one of these models (Model I) the nonlocality arises from the regularization procedure, motivated by the instanton liquid model, whereas in the second one (Model II) a separable approximation of the one-gluon exchange interaction is applied. We find that Model II predicts a larger quark mass gap, and the corresponding critical temperature at µ = 0, T c (0) 140 MeV, is in better agreement with recent lattice QCD results than the prediction of the standard local NJL model, which exceeds 200 MeV. For both models we have considered various coupling strengths in the scalar diquark channel, showing that different low-temperature quark matter phases can occur at intermediate densities: a normal quark matter (NQM) phase, a superconducting quark matter (2SC) phase and a mixed 2SC-NQM phase. In most cases, a narrow gapless 2SC phase region is also obtained at finite temperatures.

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Solitons in nonlocal chiral quark models

Cited by 41 publications

References 65 publications

Deconfinement and chiral restoration in non-local PNJL models at zero and imaginary chemical potential

Deconfinement and chiral restoration in non-local PNJL models at zero and imaginary chemical potential

Axial Excitation of the Δ in Chiral Quark Models

Phase diagram of quark matter in nonlocal chiral models under color and electric charge neutrality conditions

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