Fractured Boer-Mulders effect in the production of polarized baryons

Abstract

The fractured Boer-Mulders functions, ${\ensuremath{\Delta}}^{N}{M}_{B\ensuremath{\uparrow}/{q,q}\ensuremath{\uparrow}:p}^{q}(x,{p}_{TN};z,{\stackrel{\ensuremath{\rightarrow}}{p}}_{T}\ifmmode\cdot\else\textperiodcentered\fi{}{\stackrel{\ensuremath{\rightarrow}}{k}}_{T};{Q}^{2})$, describe an intriguing class of polarization effects for the production of baryons in the target fragmentation region of deep-inelastic processes. These functions characterize transverse momentum asymmetries related to the spin orientation for different flavors of axial-vector diquarks,${{q}_{i},{q}_{j}}\ensuremath{\uparrow}$, in an unpolarized ensemble of protons just as the familiar Boer-Mulders functions characterize transverse momentum asymmetries connected to the spin orientation of quarks in unpolarized targets. The asymmetries in ${p}_{TN}$ of the fractured Boer-Mulders effect originating in the proton distribution function can be separated kinematically, both in semi-inclusive deep-inelastic scattering and in the Drell-Yan process, from the asymmetries in ${k}_{TN}$ of the polarizing fracture functions, ${\ensuremath{\Delta}}^{N}{M}_{B\ensuremath{\uparrow}/(q,q):p}^{q}(x,p_{T}{}^{2};z,{k}_{TN};{Q}^{2})$, generated during the soft color rearrangement of the fragmentation process. The experimental requirements for this separation are presented in this article and it is shown that the fractured Boer-Mulders effect should change sign between Drell-Yan and semi-inclusive deep-inelastic scattering while the polarizing fracture functions remain the same. Simple isospin arguments indicate the two polarization mechanisms should give significantly different results for the production of polarized $\ensuremath{\Lambda}$'s and $\ensuremath{\Sigma}$'s.