Experimental demonstration of coherent electron cooling of hadrons
In plain words
In coherent electron cooling each ion imprints a density ripple on a co-moving electron beam, the ripple is amplified, and it then pushes the ion back toward the ideal energy; this has not yet been seen to cool a beam.
Precise statement
In coherent electron cooling (CeC) or its microbunched variant (MBEC), hadrons modulate the density of a co-moving electron beam, the modulation is amplified (FEL or plasma-cascade amplifier) and its field acts back on the same hadrons. Determine experimentally whether such a section produces a measurable reduction of hadron energy spread or emittance, with a cooling rate within a factor 2 of theory.
What would settle it
A measured reduction of hadron bunch length, energy spread or emittance that switches off when the electron beam or amplifier is detuned.
Status in the literature
Unverified note
Proof-of-principle work at the BNL RHIC ring reported amplifier, beam-dynamics and diagnostic results; conference and journal records checked through mid-2026 report no observed cooling of hadrons.