Spin physics with antiprotons

TL;DR

This paper explores the potential of using polarized antiproton beams at GSI to study nucleon structure through various spin-dependent processes, proposing experimental setups and analyzing expected outcomes.

Contribution

It introduces new experimental possibilities with polarized antiprotons for probing nucleon structure, including Drell-Yan processes and hyperon production, with detailed rate estimates and apparatus design.

Findings

Access to parton distribution functions via Drell-Yan processes without fragmentation interference.

Potential to measure spin asymmetries in hyperon production and single spin asymmetries.

Feasibility of experiments with estimated counting rates and proposed apparatus.

Abstract

New possibilities arising from the availability at GSI of antiproton beams, possibly polarised, are discussed. The investigation of the nucleon structure can be boosted by accessing in Drell-Yan processes experimental asymmetries related to cross-sections in which the parton distribution functions (PDF) only appear, without any contribution from fragmentation functions; such processes are not affected by the chiral suppression of the transversity function $h_1(x)$. Spin asymmetries in hyperon production and Single Spin Asymmetries are discussed as well, together with further items like electric and magnetic nucleonic form factors and open charm production. Counting rates estimations are provided for each physical case. The sketch of a possible experimental apparatus is proposed.