Experimental confirmation that the proton is asymptotically a black disk

Area of Science:

• High Energy Physics
• Quantum Chromodynamics (QCD)

Background:

• Experimental measurements of inelastic proton-proton (pp) cross sections at the Large Hadron Collider (LHC) and Auger Observatory.
• Theoretical limits on cross sections, such as the Froissart bound.

Purpose of the Study:

• To analyze high-energy pp collision data to understand proton-proton interactions at extreme energies.
• To experimentally verify hypotheses of analyticity and unitarity in particle physics.

Main Methods:

• Analysis of inelastic pp cross section data from LHC (7000 GeV) and Auger (57,000 GeV).
• Comparison of experimental results with theoretical predictions, including the Froissart bound and black disk model.

Main Results:

• Inelastic and total cross sections (σ(inel) and σ(tot)) saturate the Froissart bound (ln(2)s).
• The ratio σ(inel)/σ(tot) approaches 0.5, consistent with a black disk model.
• The forward scattering amplitude becomes purely imaginary, supporting the black disk hypothesis.

Conclusions:

• Protons behave as totally absorbing black disks at infinite energies.
• The findings suggest a connection between QCD and the black disk model, with gluons forming the disk.
• The estimated lowest-lying glueball mass is 2.97 ± 0.03 GeV.