Tagged spectator DIS off a polarized spin-1 target

Abstract

We discuss the process of deep-inelastic electron scattering (DIS) on the polarized deuteron with detection of a nucleon in the nuclear fragmentation region ("spectator tagging"). We cover (a) the general structure of the DIS cross section; (b) the structure functions of the process in the impulse approximation using deuteron light-front wave functions; (c) the extraction of free neutron structure by extracting the residue of observables at the free nucleon pole ("pole extrapolation"). As an application we consider the extraction of the free neutron structure function g 1n through polarized electron scattering on the longitudinally polarized deuteron with proton tagging and on-shell extrapolation in the recoil momentum, possible at an EIC with polarized deuteron beams and forward detectors.

Tensor-polarized structure function b1 in the standard convolution description of the deuteron

“…in terms of the spin-dependent factors and structure functions [18]. Here, the z axis is taken along the virtual-photon momentum direction (q=jqj).…”

“…There are related studies to the spin-1 hadron structure on a polarized proton-deuteron Drell-Yan process [8][9][10], leptoproduction of a spin-one hadron [11], fragmentation functions [12], generalized parton distributions [13], target-mass corrections [14], positivity constraints [15], lattice QCD estimates [16], and angular momenta for the spin-1 hadron [17]. The spin-1 deuteron structure can be also investigated by tagging the final state proton [18]. In addition, it is a unique opportunity to investigate the gluon transversity distribution, which exists only for hadrons with spin ≥ 1 [19].…”

“…We can use the same model for the deuteron in describing the structure functions including b 1 . In addition, we can also use another convolution description of the virtual nucleon approximation [25][26][27], which is used for describing the tagged structure functions of the spin-1 deuteron [18].…”

“…The other is the virtual nucleon approximation in Refs. [18,[25][26][27] by considering that the virtual photon interacts with an off shell nucleon and another spectator nucleon is on mass shell. Consequently, the obtained structure function b 1 from both models is compared with the HERMES measurements.…”

DIS on a polarized spin-1 target with spectator tagging

“…In these proceedings, which is a slightly expanded version of a recent article [12], we summarize the theoretical formalism for tagging on a polarized deuteron and show estimates for the unpolarized cross section and vector polarized double spin asymmetry in kinematics accessible at an EIC. The full formalism will be presented in Ref.…”