The Fractured Boer-Mulders Effect in the Production of Polarized Baryons

TL;DR

This paper introduces the fractured Boer-Mulders functions, a novel class of polarization effects in baryon production during deep-inelastic processes, and discusses how to experimentally distinguish these effects from related polarization mechanisms.

Contribution

It proposes a new theoretical framework for fractured Boer-Mulders functions and outlines experimental methods to separate these effects from other polarization phenomena in SIDIS and Drell-Yan processes.

Findings

Fractured Boer-Mulders functions describe polarization asymmetries in baryon production.

The effect should change sign between Drell-Yan and SIDIS processes.

Different polarization mechanisms produce distinct results for lambda and sigma hyperons.

Abstract

The fractured Boer-Mulders functions describe an inriguing 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 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 of the fractured Boer-Mulders effect originating in the proton distribution function can be separated kinematically, both in SIDIS and in the Drell-Yan process from the asymmetries of the polarizing fracture functions 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 SIDIS 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 lambdas and sigmas.