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Related papers: Photon Dispersion in a Supernova Core

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We study the spin response of cold dense neutron matter in the limit of zero momentum transfer, and show that the frequency dependence of the long-wavelength spin response is well constrained by sum-rules and the asymptotic behavior of the…

Nuclear Theory · Physics 2013-02-19 G. Shen , S. Gandolfi , S. Reddy , J. Carlson

One-nucleon emission processes induced by photon absorption are studied by considering short-range correlations effects. At energies above the giant resonance region the validity of the direct knock-out model has been tested by comparison…

Nuclear Theory · Physics 2009-11-07 M. Anguiano , G. Co' , A. M. Lallena , S. R. Mokhtar

We calculate the quasifree photoproduction of pions and eta mesons on nuclei from 12C to 208Pb. Assuming that for the quasifree process the cross sections for pi/eta - photoproduction on a nucleon in medium are -- besides a lowering due to…

Nuclear Theory · Physics 2009-10-28 A. Hombach , A. Engel , S. Teis , U. Mosel

In this work, a constant and uniform magnetic field is less than the Schwinger critical value. In turn, an additional constant and uniform electric field is taken much smaller than the magnetic field value. The propagation of a photon in…

High Energy Physics - Theory · Physics 2016-08-24 V. M. Katkov

A new partial wave analysis of pion photoproduction has been obtained in the framework of fixed-t dispersion relations valid form threshold up to 500 MeV. It is based on new Mainz data for \pi^{0} and \pi^{+} production off the proton and…

Nuclear Theory · Physics 2011-04-15 L. Tiator

We generalize the sum rules for the nucleon electric plus magnetic polarizability $\Sigma=\alpha+\beta$ and for the nucleon spin-polarizability $\gamma$, to virtual photons with $Q^2>0$. The dominant low energy cross sections are…

Nuclear Theory · Physics 2009-10-31 J. Edelmann , N. Kaiser , G. Piller , W. Weise

In quantum electrodynamics, photon-photon scattering can be the result of the exchange of virtual electron-positron pairs. This gives rise to a non-trivial dispersion relation for a single photon moving on a background of electromagnetic…

High Energy Physics - Phenomenology · Physics 2008-11-26 Mattias Marklund , Gert Brodin , Lennart Stenflo , Padma K. Shukla

Propagation of photons in relativistically expanding plasma outflows, characterized by steady Lorentz factor Gamma is considered. Photons that are injected in regions of high optical depth are advected with the flow until they escape at the…

Astrophysics · Physics 2009-11-13 Asaf Pe'er

The free photon dispersion relation is a reference quantity for high precision tests of Lorentz Invariance. We first outline theoretical approaches to a conceivable Lorentz Invariance Violation (LIV). Next we address phenomenological tests…

High Energy Physics - Theory · Physics 2010-01-16 Wolfgang Bietenholz

We present a model for electron scattering off nuclei and photon absorption in the resonance energy region (W <= 2 GeV). The elementary gamma/gamma* N-vertex is described using in-medium kinematics and up-to-date form factors for…

Nuclear Theory · Physics 2008-09-16 O. Buss , T. Leitner , U. Mosel , L. Alvarez-Ruso

We investigate the effect of nuclear spins on the phase shift and polarisation rotation of photons scattered off a quantum dot-cavity system. We show that as the phase shift depends strongly on the resonance energy of an electronic…

Quantum Physics · Physics 2019-06-05 Thomas Nutz , Petros Androvitsaneas , Andrew Young , Ruth Oulton , Dara P. S. McCutcheon

Empirical formulas for the second inverse moment of the photoabsorption cross sections in nuclei are discussed in J. N. Orce, Phys. Rev. C 91, 064602 (2015). In this Comment I point out that the experimental values used are systematically…

Nuclear Experiment · Physics 2016-04-29 Peter von Neumann-Cosel

Bursts from soft gamma repeaters have been shown to be super-Eddington by a factor of 1000 and have been persuasively associated with compact objects. Here, a model of super-Eddington radiation transfer on the surface of a strongly magnetic…

Astrophysics · Physics 2009-10-22 Andrew Ulmer

The work investigates absorption of a twisted photon, which possesses quantized total angular momentum (TAM), by a relativistic electron with the Lorentz factor $\gamma \sim 1-10$ in a strong magnetic field up to the Schwinger limit, $H_c =…

High Energy Physics - Phenomenology · Physics 2024-10-28 A. A. Shchepkin , D. V. Grosman , I. I. Shkarupa , D. V. Karlovets

The photon zero-mass hypothesis has been investigated for a long time using the frequency-dependent time delays of radio emissions from astrophysical sources. However, the search for a rest mass of the photon has been hindered by the…

High Energy Astrophysical Phenomena · Physics 2018-08-08 Jun-Jie Wei , Xue-Feng Wu

In the hot and dense medium of a supernova (SN) core, the nucleon spins fluctuate so fast that the axial-vector neutrino opacity and the axion emissivity are expected to be significantly modified. Axions with $m_a\alt10^{-2}\,{\rm eV}$ are…

Astrophysics · Physics 2008-11-26 H. -T. Janka , W. Keil , G. Raffelt , D. Seckel

The association of all three soft gamma-ray repeaters (SGRs) with supernova remnants has established that SGRs are young neutron stars, and has given us a starting point for detailed modeling. One of the most popular classes of models…

Astrophysics · Physics 2015-06-24 Tomasz Bulik , M. Coleman Miller

We consider here the bremsstrahlung emission of photons at low and intermediate energies $ E_{lab}\le 1000 MeV/u$ of the projectile. and derive expressions more general than previous results obtained by Neuhauser which were limited to the…

High Energy Physics - Phenomenology · Physics 2010-11-01 L. V. Razumov , R. M. Weiner

We have simulated the time evolution of the photon number distribution in a semiconductor quantum dot-microcavity system driven by chirped laser pulses and compare with unchirped results. When phonon interactions with the dot are…

Mesoscale and Nanoscale Physics · Physics 2020-05-20 M. Cosacchi , T. Seidelmann , F. Ungar , M. Cygorek , A. Vagov , V. M. Axt