The charge and matter distributions of<sup>208</sup>Pb

Brown, B. A.; Massen, S. E.; Escudero, J I; Hodgson, P. E.; Madurga, G.; Viñas, X.

doi:10.1088/0305-4616/9/4/009

Cited by 25 publications

(18 citation statements)

References 51 publications

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“…The universal scaling conjecture of Ref. [77] is inconsistent with the anticorrelation we observe between the µ-dependence of f π and m π .…”

Section: 4)contrasting

confidence: 96%

Nonperturbative effects in QCD at finite temperature and density

Roberts¹

1999

Phys. Part. Nucl.

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These lecture notes illustrate the application of Dyson-Schwinger equations in QCD. The extensive body of work at zero temperature and chemical potential is represented by a selection of contemporary studies that focus on solving the Bethe-Salpeter equation, deriving an exact mass formula in QCD that describes light and heavy pseudoscalar mesons simultaneously, and the calculation of the electromagnetic pion form factor and the vector meson electroproduction cross sections. These applications emphasise the qualitative importance of the momentum-dependent dressing of elementary Schwinger functions in QCD, which provides a unifying connection between disparate phenomena. They provide a solid foundation for an extension of the approach to nonzero temperature and chemical potential. The essential, formal elements of this application are described and four contemporary studies employed to exemplify the method and its efficacy. They study the demarcation of the phase boundary for deconfinement and chiral symmetry restoration, the calculation of bulk thermodynamic properties of the quark-gluon plasma and the response of π-and ρ-meson observables to T and µ. Along the way a continuum order parameter for deconfinement is introduced, an anticorrelation between the response of masses and decay constants to T and their response to µ elucidated, and a (T, µ)-mirroring of the slow approach of bulk thermodynamic quantities to their ultrarelativistic limit highlighted. These effects too are tied to the momentum-dependent dressing of the elementary Schwinger functions.

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“…The universal scaling conjecture of Ref. [77] is inconsistent with the anticorrelation we observe between the µ-dependence of f π and m π .…”

Section: 4)contrasting

confidence: 96%

Nonperturbative effects in QCD at finite temperature and density

Roberts¹

1999

Phys. Part. Nucl.

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“…Skm * is chosen because it provides one of the best overall fits to the charge density [40]. The experimental charge densities (black) come from model independent analysis of electron scattering data and muonic atom data-min-max lines from [41,42], circles from [43], and crosses from [44]. The charge density is well constrained between r = 2 and r = 8 fm.…”

Section: Modelmentioning

confidence: 99%

Neutron skin deduced from antiprotonic atom data

et al. 2007

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The relationship between the nucleon density at large radii and the value of the rms radius is investigated in the framework of Skyrme Hartree-Fock and relativistic mean-field models. From a comparison to the charge density we constrain the models in terms of the nuclear matter incompressibility and effective mass properties required to reproduce the density shape. The results are used to extract the rms neutron radius for 208 Pb from antiprotonic atom data. The result for the difference between the neutron and proton rms radii, the so-called neutron-skin thickness, is S = 0.20(±0.04)(±0.05) fm, where ±0.04 fm is experimental error from the antiprotonic line width, and ±0.05 fm is the theoretical error suggested from the comparison of the models with the experimental charge density.The neutron-skin thickness is defined by S = R n − R p where R n and R p are the rms radii for point neutrons and protons, respectively. The neutron skin in heavy nuclei has been shown to be a unique measure of the density dependence of the neutron equation of state (EOS) near nuclear saturation density [1][2][3]. The density-dependent properties of the neutron EOS have a strong impact on the models of neutron stars [3][4][5][6][7]. Proton rms radii R p for stable nuclei are determined at a high level accuracy from electron scattering and muonic atom data. The charge rms radius obtained for 208 Pb is R ch = 5.5013(7) fm [8], which gives R p = 5.45 fm after taking into account the finite-size effects of the protons and neutrons [9]. Neutron rms radii are much more difficult to accurately determine. A model independent method of using the parity violating asymmetry in elastic scattering of electrons from 208 Pb to measure R n to a 1% (± 0.05 fm) accuracy is proposed for the PREX experiment at JLab [10]. There have been renewed attempts to obtain R n from hadronic scattering data [11,12], but the error due to the many-body strong interaction effects is difficult to quantify [13]. A third method has been to use antiprotonic atom data to constrain the properties of the matter density at large radii [14]. In this article we will explore how the densities at large radii are related to nuclear matter properties and to the neutron rms radius.A recent analysis of the x-ray cascade of antiprotonic atoms [15] has been carried out with zero-range and finite range models for the antiproton nucleus interactions. The analysis is based on two-parameter Fermi (2pF) shapes for the densities; ρ(r) = ρ 0 /[1 + exp(r − c)/a]. The proton density was fixed from the measured charge density using the 2pF shape fit obtianed by Fricke et al. [8] transformed to a 2pF shape for point-protons with the formula of Oset et al. [16]. Then a 2pF shape for neutrons was added. The matter density is the sum of the 2pF densities for protons and neutrons. In [15] equally good fits are obtained for a wide range of correlated c and a combinations for the neutron density with the resulting matter density curves shown in Fig. 1. The curves cross near r = 9.8 fm indicating that th...

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“…Among the first ones we can mention the relativized versions of the constituent quark model [2,3] and the light front constituent quark model [4,5]. Among the second ones the breathing bag model [6,7] and the hybrid state descriptions [8,9,10,11] which confer to the Roper an exotic nature. Nonetheless a unified description of the Roper phenomenology has not been achieved and its nature is still under discussion.…”

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confidence: 99%

A consistent explanation of the Roper phenomenology

Cano

González

1998

Physics Letters B

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We study the electromagnetic transitions of the Roper N(1440) resonance. Our results, when combined with the previously obtained for the mass and the pionic strong decay widths of the Roper, show that within a non-relativistic constituent quark model scheme, a comprehensible understanding of the Roper phenomenology can be achieved. They also seem to support the view of the Roper as a radial excitation of the nucleon, though more experimental data are needed to reach a definitive conclusion.Comment: 14 pages, 4 figures (7 postscript files). Some referencess adde

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The charge and matter distributions of²⁰⁸Pb

Cited by 25 publications

References 51 publications

Nonperturbative effects in QCD at finite temperature and density

Nonperturbative effects in QCD at finite temperature and density

Neutron skin deduced from antiprotonic atom data

A consistent explanation of the Roper phenomenology

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The charge and matter distributions of208Pb

Cited by 25 publications

References 51 publications

Nonperturbative effects in QCD at finite temperature and density

Nonperturbative effects in QCD at finite temperature and density

Neutron skin deduced from antiprotonic atom data

A consistent explanation of the Roper phenomenology

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Product

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The charge and matter distributions of²⁰⁸Pb