We present an innovative approach to the linearly polarized gluons confined
inside the unpolarized nucleon in lepton-nucleon scattering. Our method
analyzes the correlation of energy flows at azimuthal separations ϕ. The
interference of the spinning gluon with both positive and negative helicities
translates into a cos(2ϕ) asymmetry imprinted on the detector. Unlike the
conventional transverse momentum dependent (TMD) probes, the cos(2ϕ)
asymmetry in this approach is preserved by rotational symmetry, holds to all
orders, and is free of radiation contamination, thus expected to provide the
exquisite signature of the nucleon linearly polarized gluons.Comment: 6 pages, 5 figure