Classical Electromagnetic Fields from Quantum Sources in Heavy-Ion Collisions

Electromagnetic fields are generated in high energy nuclear collisions by spectator valence protons. These fields are traditionally computed by integrating the Maxwell equations with point sources. One might expect that such an approach is valid at distances much larger than the proton size and thus such a classical approach should work well for almost the entire interaction region in the case of heavy nuclei. We argue that, in fact, the contrary is true: due to the quantum diffusion of the proton wave function, the classical approximation breaks down at distances of the order of the system size. We compute the electromagnetic field created by a charged particle described initially as a Gaussian wave packet of width 1 fm and evolving in vacuum according to the Klein-Gordon equation. We completely neglect the medium effects. We show that the dynamics, magnitude and even sign of the electromagnetic field created by classical and quantum sources are different.Comment: 12 pages, 4 figures. V2: a numerical error corrected, figures improved, other minor improvement

Quantum diffusion of electromagnetic fields of ultrarelativistic spin-half particles

We compute electromagnetic fields created by a relativistic charged spin-half particle in empty space at distances comparable to the particle Compton wavelength. The particle is described as a wave packet evolving according to the Dirac equation. It produces the electromagnetic field that is essentially different from the Coulomb field due to the quantum diffusion effect.Comment: 10 pages, 10 figure

Electromagnetic Fields from Quantum Sources in Heavy Ion Collisions

We compute electromagnetic fields created by a relativistic charged spin-half particle in empty space at distances comparable to the particle Compton wavelength. The particle is described as a wave packet evolving according to the Dirac equation. It produces the electromagnetic field that is essentially different from the Coulomb field due to the quantum diffusion effect.</p

Quantum diffusion of electromagnetic fields of ultrarelativistic spin-half particles

We compute electromagnetic fields created by a relativistic charged spin-half particle in empty space at distances comparable to the particle Compton wavelength. The particle is described as a wave packet evolving according to the Dirac equation. It produces the electromagnetic field that is essentially different from the Coulomb field due to the quantum diffusion effect.This is a manuscript of an article published as Peroutka, Balthazar, and Kirill Tuchin. "Quantum diffusion of electromagnetic fields of ultrarelativistic spin-half particles." Nuclear Physics A 966 (2017): 64-72. DOI: 10.1016/j.nuclphysa.2017.05.104. Posted with permission.</p

Electromagnetic fields from quantum sources in heavy-ion collisions

We compute the electromagnetic field created by an ultrarelativistic charged particle in vacuum at distances comparable to the particle Compton wavelength. The wave function of the particle is governed by the Klein-Gordon equation, for a scalar particle, or the Dirac equation, for a spin-half particle. The produced electromagnetic field is essentially different in magnitude and direction from the Coulomb field, induced by a classical point charge, due to the quantum diffusion effect. Thus, a realistic computation of the electromagnetic field produced in heavy-ion collisions must be based upon the full quantum treatment of the valence quarks.Peroutka, Balthazar, and Kirill Tuchin. "Electromagnetic fields from quantum sources in heavy-ion collisions." Nuclear Physics A 967 (2017): 860-863. DOI: 10.1016/j.nuclphysa.2017.05.048. Posted with permission.</p

Classical electromagnetic fields from quantum sources in heavy-ion collisions

Electromagnetic fields are generated in high energy nuclear collisions by spectator valence protons. These fields are traditionally computed by integrating the Maxwell equations with point sources. One might expect that such an approach is valid at distances much larger than the proton size and thus such a classical approach should work well for almost the entire interaction region in the case of heavy nuclei. We argue that, in fact, the contrary is true: due to the quantum diffusion of the proton wave function, the classical approximation breaks down at distances of the order of the system size. We compute the electromagnetic field created by a charged particle described initially as a Gaussian wave packet of width 1 fm and evolving in vacuum according to the Klein–Gordon equation. We completely neglect the medium effects. We show that the dynamics, magnitude and even sign of the electromagnetic field created by classical and quantum sources are different.This is a manuscript of an article published as Holliday, Robert, Ryan McCarty, Balthazar Peroutka, and Kirill Tuchin. "Classical electromagnetic fields from quantum sources in heavy-ion collisions." Nuclear Physics A 957 (2017): 406-415. DOI: 10.1016/j.nuclphysa.2016.10.003. Posted with permission.</p