Lowest laser intensity for observable dynamically assisted Schwinger pairs · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title
Lowest laser intensity for observable dynamically assisted Schwinger pairs
Plain
Pulling pairs out of empty space with a field alone needs a field about a thousand times stronger than the best lasers give, which is several million times their intensity. Adding a weak fast-oscillating field could lower the barrier, and the question is how much.
Precise · changed · core
Revision 1: The Schwinger rate in a constant field, $w = (e E)^2/(4\pi^3 \hbar^2 c)\operatorname{exp}(-\pi E_S/E)$ with $E_S \sim 4.4e13\,\mathrm{statvolt}/\mathrm{cm}$, is negligible at the $E/E_S \sim 1e-3$ of present peak laser fields (peak intensity about $1e30\,\mathrm{erg}\,\mathrm{s}^{-1}\,\mathrm{cm}^{-2}$, approximate), where $\operatorname{exp}(-\pi E_S/E) \sim \operatorname{exp}(-3000)$. Superposing a weak high-frequency field (dynamically assisted Schwinger mechanism, Schuetzhold, Gies and Dunne 2008) reduces the exponent. For realistic focused optical pulses combined with XFEL or gamma-ray photons, determine the minimal strong-field intensity at which the nonperturbative assisted yield reaches 1 pair per shot, and specify an observable that separates it from perturbative multiphoton Breit-Wheeler pairs.
Revision 2: The Schwinger rate in a constant field, $w = (e E)^2/(4\pi^3 \hbar^2 c)\exp(-\pi E_S/E)$ with $E_S \sim 4.4 \times 10^{13}\,\mathrm{statvolt}/\mathrm{cm}$, is negligible at the $E/E_S \sim 10^{-3}$ of present peak laser fields (peak intensity about $10^{30}\,\mathrm{erg}\,\mathrm{s}^{-1}\,\mathrm{cm}^{-2}$, approximate), where $\exp(-\pi E_S/E) \sim \exp(-3000)$. Superposing a weak high-frequency field (dynamically assisted Schwinger mechanism, Schuetzhold, Gies and Dunne 2008) reduces the exponent. For realistic focused optical pulses combined with XFEL or gamma-ray photons, determine the minimal strong-field intensity at which the nonperturbative assisted yield reaches 1 pair per shot, and specify an observable that separates it from perturbative multiphoton Breit-Wheeler pairs.
Settled by
Calculations of assisted pair yields in realistic 3D focused field geometries beyond the locally constant field approximation, followed by a measurement at the predicted threshold.
Kind
well-posed
Answer type
value
References
(empty)
Literature status
open
Status note
(empty)
Posed since
2008

Decisions