arXiv · 2609.28700
Measuring Dual-Superconductor Length Scales in the QCD Vacuum at HERA
Abstract
In the dual superconductor picture, the QCD vacuum is a condensate of chromomagnetic monopoles characterised by two lengths: the penetration depth $λ$ of the chromoelectric field and the coherence length $ξ$ of the condensate. These have previously been accessible only through lattice calculations of static flux tubes. We show that they can instead be measured in exclusive diffraction, where the transverse profile of a gluonic hotspot is the vacuum's response to a localised color source. We therefore use the Clem vortex profile to describe the hotspot geometry. Fitting Clem's vortex profile to all 104 available H1 and ZEUS exclusive $J/ψ$ photoproduction points, spanning $|t|<30~{\rm GeV}^2$ and $40\leq W\leq 251~{\rm GeV}$, we obtain $χ^2/{\rm ndf}=0.72$ and extract $λ=0.19(2)~{\rm fm}$, $ξ_v=0.087(13)~{\rm fm}$, and a Ginzburg--Landau parameter $κ=2.7(7)$, corresponding to the type-II regime. The corresponding vector mass $1/λ=1.03(11)~{\rm GeV}$ agrees with lattice determinations of the lightest gluelump. The resulting Ginzburg--Landau string tension implied by $λ$ and $κ$ reproduces the QCD string tension well; the matching requires $α_S=0.37(9)$ compared with $α_S(1/λ^2)=0.36(2)$ in the same LO scheme used for the dipole amplitude calculation.
Explore related subjects
Keep this discovery
Explore connections, maps & timelines
Tobias Toll, Nahid Vasim. 2026-09-23. Measuring Dual-Superconductor Length Scales in the QCD Vacuum at HERA. https://arxiv.org/abs/2609.28700
Cite the original work for its findings. Save a collection to share your selection of sources.