Year: 2008
Type: article
Abstract: Electron-positron pair creation in supercritical electric fields limits the net charge of any static, spherical object, such as superheavy nuclei, strangelets, and $Q$ balls, or compact stars like neutron stars, quark stars, and black holes. For radii between $4\ifmmode\times\else\texttimes\fi{}{10}^{2}$ and ${10}^{4}\text{ }\text{ }\mathrm{fm}$ the upper bound on the net charge is given by the universal relation $Z=0.71{R}_{\mathrm{fm}}$, and for larger radii (measured in femtometers or kilometers) $Z=7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}{R}_{\mathrm{fm}}^{2}=7\ifmmode\times\else\texttimes\fi{}{10}^{31}{R}_{\mathrm{km}}^{2}$. For objects with nuclear density the relation corresponds to $Z\ensuremath{\approx}0.7{A}^{1/3}$ (${10}^{8}{10}^{12}$), where $A$ is the baryon number. For some systems this universal upper bound improves existing charge limits in the literature.
Source: Physical Review Letters
Author: Jes Madsen
Institution: Aarhus University
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1978096367