Probing the vacuum with highly charged ions

Abstract

The physics of the Fermion vacuum is briefly described, and applied to pair production in heavy ion collisions. We consider in turn low energies (< 50 MeV/nucleon), intermediate energies (< 5 GeV/nucleon), and ultrahigh energies such as would be produced in. a ring collider. At high energies, interesting questions of Lorentz and gauge invariance arise. Finally, some applications to the structure of high Z atoms are examined. DISCLAIMER

Impact-parameter dependence of multiple lepton-pair production from electromagnetic fields

“…When heavy ions collide at relativistic velocities, the Lorentz-contracted electromagnetic fields in the space-time region near the collision are sufficiently intense to produce large numbers of electron-positron pairs, muon pairs, vector bosons, and possibly the yet-unconfirmed Higgs boson. All these processes occur at nearly atomic distance scales [1][2][3]. The phenomena involved are pervasive, impinging upon atomic, nuclear, and particle physics.…”

“…However, suggestions by several authors indicate that other sources of lepton pairs might possibly mask the leptonic signals originating from the plasma phase [7][8][9]. Electromagnetic production from the vacuum of single-and multiple-lepton pairs is a major contribution to this physical background [10,1] and, therefore, must be understood in detail. In addition, two very abundant electromagnetic processes constitute the primary limitation to the lifetime of stored beams at RHIC.…”

Coherent electromagnetic production of mu and tau lepton pairs in relativistic heavy-ion collisions

“…The mechanisms for producing W-pairs are also candidates for producing the Higgs. Finally, previous work [5] has raised serious questions concerning the coherent mechanisms for electron-positron production in relativistic heavy-ion collisions. These questions have grown ever more intriguing since they were first posed, and raise the issue as to whether measurements of these processes can provide new information on nuclear and nucleon electromagnetic form factors.…”

“…There is evidence from model studies [5] that pair production in heavy-ion collisions is non-perturbative at high energies. This is supported by the observations that Za is not small, and that perturbative calculations violate unitary, and in particular, they violate the Froissart bound on cross sections.…”