Probing the quantum-mechanical equivalent-photon spectrum for electromagnetic dissociation of relativistic uranium projectiles

Due to coherence, there are strong electromagnetic fields of short duration in very peripheral collisions. They give rise to photon-photon and photon-nucleus collisions with a high flux up to an invariant mass region hitherto unexplored experimentally. After a general survey of the field equivalent photon numbers and photon-photon luminosities, especially for relativistic heavy ion collisions, are discussed. Special care needs to be taken to include the effects of the strong interaction and nuclear size in this case. Photon-photon and photon-hadron physics at various invariant mass scales are then discussed. The maximum equivalent photon energy in the lab-system (collider frame) are typically of the order of 3 GeV for RHIC and 100 GeV for LHC. Diffractive processes are an important background process. Lepton-pair, especially electron-positron pair production is copious. Due to the strong fields there will be new phenomena, like multiple e + e − pair production. The experimental techniques to select γγ-processes are finally discussed together with important background processes.

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“…2.3 of [16]. In addition the results of [83] were compared to experimental data for giant resonance excitations in [86].…”

Section: Effects Of Strongly Interacting Particlesmentioning

confidence: 99%

Coherent γγ and γA interactions in very peripheral collisions at relativistic ion colliders

et al. 2002

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“…As the name implies, the EPA is an approximation, with certain ranges of validity, different for the semiclassical and plane wave approaches, see, e.g., [295] and [296]. In [297] experimental data for electromagnetic excitation with heavy ions were analysed using the EPA spectrum of [296]. In contrast to semiclassical calculations, systematically lower cross sections are obtained that cannot reproduce the experimental results.…”

mentioning

confidence: 99%

Electromagnetic dissociation as a tool for nuclear structure and astrophysics

Baur¹,

Typel²,

Hencken³

et al. 2001

Progress in Particle and Nuclear Physics

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Coulomb dissociation is an especially simple and important reaction mechanism. Since the perturbation due to the electric field of the (target) nucleus is exactly known, firm conclusions can be drawn from such measurements. Electromagnetic matrixelements and astrophysical S-factors for radiative capture processes can be extracted from experiments. We describe the basic elements of the theory of nonrelativistic and relativistic electromagnetic excitation with heavy ions. This is contrasted to electromagnetic excitation with leptons (electrons), with their small electric charge and the absence of strong interactions. We discuss various approaches to the study of higher order electromagnetic effects and how these effects depend on the basic parameters of the experiment. The dissociation of neutron halo nuclei is studied in a zero range model using analytical methods. We also review ways how to treat nuclear interactions, show their characteristics and how to avoid them (as far as possible). We review the experimental results from a theoretical point of view. Of special interest for nuclear structure physics is the appearence of low lying electric dipole strength in neutron rich nuclei. Applications of Coulomb dissociation to some selected radiative capture reactions relevant for nuclear astrophysics are discussed. The Coulomb dissociation of 8 B is relevant for the solar neutrino problem. The potential of the method especially for future investigations of (medium) heavy exotic nuclei for nuclear structure and astrophysics is explored. We conclude that the Coulomb dissociation mechanism is theoretically well understood, the potential difficulties are identified and can be taken care of. Many interesting experiments have been done in this field and many more are expected in the future.

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Electromagnetic dissociation as a tool for nuclear structure and astrophysics

Baur

Hencken²,

Trautmann³

et al. 2003

Progress in Particle and Nuclear Physics

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Coulomb dissociation is an especially simple and important reaction mechanism. Since the perturbation due to the electric field of the nucleus is exactly known, firm conclusions can be drawn from such measurements. Electromagnetic matrix elements and astrophysical S-factors for radiative capture processes can be extracted from experiments. We describe the basic theory, new results concerning higher order effects in the dissociation of neutron halo nuclei, and briefly review the experimental results obtained up to now. Some new applications of Coulomb dissociation for nuclear astrophysics and nuclear structure physics are discussed.

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Probing the quantum-mechanical equivalent-photon spectrum for electromagnetic dissociation of relativistic uranium projectiles

Cited by 3 publications

References 42 publications

Coherent γγ and γA interactions in very peripheral collisions at relativistic ion colliders

Coherent γγ and γA interactions in very peripheral collisions at relativistic ion colliders

Electromagnetic dissociation as a tool for nuclear structure and astrophysics

Electromagnetic dissociation as a tool for nuclear structure and astrophysics

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