The Lamb Shift and Ultra High Energy Cosmic Rays

She-Sheng Xue

Published 2002-07-03, updated 2003-05-19Version 2

On the analogy with the Lamb shift, we study the vacuum effect that proton's electric field interacts with virtual particles in the vacuum. We find a possible quantum instability that triggered by an external force, proton's electric field interacting with virtual particles spontaneously induces a quantum force that back reacts on the proton in the direction of the external trigger force. Such a quantum-induced force accelerates the proton runaway, by gaining the zero-point energy from the vacuum (~10^{-5} eV/cm). This effect possibly accounts for the mysterious origin and spectrum of ultra high-energy cosmic ray (UHECR) events above 10^{20}eV, and explains the puzzle why the GZK cutoff is absent. The candidates of these events could be primary protons from the early Universe.