Universal Charge-Radius Relation for Subatomic and Astrophysical Compact Objects

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 $4\times 10^2$ fm and $10^4$ fm the upper bound on the net charge is given by the universal relation $Z=0.71R_{fm}$, and for larger radii (measured in fm or km) $Z=7\times 10^{-5}{R}_{fm}^2=7\times 10^{31}{R}_{km}^2$. For objects with nuclear density the relation corresponds to $Z\approx 0.7A^{1/3}$ ($10^8<A<10^{12}$) and $Z\approx 7\times 10^{-5}{A}^{2/3}$ ($A>10^{12}$), where $A$ is the baryon number. For some systems this universal upper bound improves existing charge limits in the literature.

Cited by in corpus (3)

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• Thickness of the strangelet-crystal crust of a strange star
• Critical Charges on Strange Quark Nuggets and Other Extended Objects