Off-the-energy-shell properties of the mass operator and spectral functions in nuclear matter

Baldo, M.; Bombaci, Ignazio; Giansiracusa, G.; Lombardo, U.; Mahaux, C.; Sartor, R.

doi:10.1016/0375-9474(92)90529-s

Cited by 58 publications

(49 citation statements)

References 32 publications

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“…If the interaction between the fermions is known these equations can be solved numerically by iteration. In the context of nuclear physics this scheme is known also as the Self-Consistent Green's Functions (SCGF) method [5,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46]. Once the single particle Green's function (or equivalently the self-energy) is determined, the free energy of the system can be computed from the thermodynamic relation…”

Section: The Ladder T-matrix Theorymentioning

confidence: 99%

The physics of dense hadronic matter and compact stars

Sedrakian

2007

Progress in Particle and Nuclear Physics

125

109

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This review describes the properties of hadronic phases of dense matter in compact stars. The theory is developed within the method of real-time Green's functions and is applied to study of baryonic matter at and above the saturation density. The non-relativistic and covariant theories based on continuum Green's functions and the T -matrix and related approximations to the selfenergies are reviewed. The effects of symmetry energy, onset of hyperons and meson condensation on the properties of stellar configurations are demonstrated on specific examples. Neutrino interactions with baryonic matter are introduced within a kinetic theory. We concentrate on the classification, analysis and first principle derivation of neutrino radiation processes from unpaired and superfluid hadronic phases. We then demonstrate how neutrino radiation rates from various microscopic processes affect the macroscopic cooling of neutron stars and how the observed X-ray fluxes from pulsars constrain the properties of dense hadronic matter. Contents IntroductionNeutron stars are born in a gravitational collapse of luminous stars whose core mass exceeds the Chandrasekhar limit for a self-gravitating body supported by degeneracy pressure of electron gas [1]. Being the densest observable bodies in our universe they open a window on the physics of matter under extreme conditions of high densities, pressures and strong electromagnetic and gravitational fields. Most of the known pulsars are isolated objects which emit radio-waves at frequencies 10 8 − 10 10 Hz, which are pulsed at the rotation frequency of the star. Young objects, like the pulsar in the Crab nebula, are also observed through X-rays that are emitted from their surface as the star radiates away its thermal energy. Relativistic magnetospheres of young pulsars emit detectable non-thermal optical and gamma radiation; they could be sources of high-energy elementary particles. Neutron stars in the binaries are powered by the energy of matter accreted from companion star.The radio observations of pulsars stretch back to 1967 when the first pulsar was discovered. Since then, the observational pulsar astronomy has been extremely important to the fundamental physics and 2 astrophysics, which is evidenced by two Nobel awards, one for the discovery of pulsars (Hewish 1974) [2], the other for the discovery of the first neutron star -neutron star binary pulsar (Hulse and Taylor, 1993) [3] whose orbital decay confirmed the gravitational radiation in full agreement with Einstein's General Theory of Relativity. The measurements of neutron star (NS) masses in binaries provide one of the most stringent constraint on properties of the superdense matter. The timing observations of the millisecond pulsars set an upper limit on the angular momentum that can be accommodated by a stable NS -a limit that can potentially constrains the properties of dense matter. Noise and rotational anomalies that are superimposed on the otherwise highly stable rotation of these objects provide a clue to the ...

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Section: The Ladder T-matrix Theorymentioning

confidence: 99%

The physics of dense hadronic matter and compact stars

Sedrakian

2007

Progress in Particle and Nuclear Physics

125

109

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“…In refs. [3][4][5] it is shown that the quasiparticle description is only valid near the Fermi energy. In general, the spectral function has a considerable width indicating that the one-particle states are strongly damped at the saturation density.…”

Section: Introductionmentioning

confidence: 99%

“…In general, the spectral function has a considerable width indicating that the one-particle states are strongly damped at the saturation density. Baldo et al [3] calculated the on-and off-shell properties of the nucleon mass operator and the nucleon spectral function. They stressed the importance to retain the full frequency dependence of the selfenergy for the calculation of the spectral function.…”

Section: Introductionmentioning

confidence: 99%

Nucleon spectral function at finite temperature and the onset of superfluidity in nuclear matter

et al. 1996

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Nucleon selfenergies and spectral functions are calculated at the saturation density of symmetric nuclear matter at finite temperatures. In particular, the behaviour of these quantities at temperatures above and close to the critical temperature for the superfluid phase transition in nuclear matter is discussed. It is shown how the singularity in the thermodynamic T-matrix at the critical temperature for superfluidity (Thouless criterion) reflects in the selfenergy and correspondingly in the spectral function. The real part of the on-shell selfenergy (optical potential) shows an anomalous behaviour for momenta near the Fermi momentum and temperatures close to the critical temperature related to the pairing singularity in the imaginary part. For comparison the selfenergy derived from the K-matrix of Brueckner theory is also calculated. It is found, that there is no pairing singularity in the imaginary part of the selfenergy in this case, which is due to the neglect of hole-hole scattering in the K-matrix. From the selfenergy the spectral function and the occupation numbers for finite temperatures are calculated.(MPG-VT-UR 65/95, submitted to Phys. Rev. C) 1

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“…This is not appropriate in nuclear physics, in which V (S) is extremely large and repulsive because of the shortrange repulsion contained in the nucleon nucleon interaction [58,59]. In contrast, V (S) can be viewed as an approximation to M(E) in atomic physics [60,61].…”

Section: High Energy Limit Or``static Part'' Of the Mass Operatormentioning

confidence: 98%