No abstract

We extend the results of [Phys.Rev.Lett. 128 (2022) 18], where we argued that in the controlled environment of the Deep Inelastic Scattering experiments, Bose-Einstein correlation between gluons in a hadronic wave function can be accessed through the production of the diffractive dijet plus a third jet. In this observable, Bose-Einstein correlation causes the enhancement of the production cross sections at the zero relative angle between the transverse momentum imbalance of the photongoing dijet and the transverse momentum of the gluon jet, when the magnitude of the momentum imbalance is about the same as the magnitude of the produced gluon. In the present paper, we account for multiple scattering and non-linear effect in the target wave function. Although our equations can be applied to any high-energy DIS kinematics, to make them tractable numerically, we consider the high-momentum limit (momentum larger than Q s ) for the total momentum of the dijet, momentum imbalance, and the momentum of the produced gluon. By performing explicit numerical calculations, we confirm that the signal is present after accounting for multiple scattering.

Understanding the spin structure of hadrons in the small x regime is an important direction to unravel the spin puzzle in hadronic physics. To include spin degrees of freedom in the small x regime requires going beyond the usual eikonal approximation in high energy QCD. We developed an effective Hamiltonian approach to study spin related observables in the small x regime using the shockwave formalism. The small-x effective Hamiltonian incorporates both quark and gluon propagators in the background fields and the background field induced interaction vertices up to next-to-eikonal order. A novel feature of sub-eikonal interactions is the background gluon field induced gluon radiation inside the shockwave. Its relation to chromo-electrically polarized Wilson line correlator is established both in small x helicity evolution and in longitudinal double-spin asymmetry for gluon production.