Conference Presentation

PUBDB-2026-00059

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Final-state polarization of lepto-produced $\Lambda$ hyperons

Miyachi, Y.Extern* ; Schnell, G. (Corresponding author)Extern* ; Shibata, T.Extern* ; HERMES Collaboration (Collaboration author)

2025

Abstract: Hyperon polarization in high-energy reactions has been an intriguing and puzzling topic in QCD for 50 years, starting with the surprising observation of large transverse hyperon polarization produced in collision of unpolarized hadrons. Hyperons are especially interesting in this regard as their weak decay provides access to their polarization via an asymmetric decay distribution, something that can be analyzed relatively easily. The HERMES experiment at DESY, utilizing the 27.6 GeV electron or positron beam of HERA impinging on pure nuclear gas targets was dedicated to the study of mainly the spin structure of the proton but also other spin effects. Transverse polarization of Lambda hyperons in the scattering of unpolarized leptons by unpolarised nuclei has been observed and spin correlations between the polarized leptons and final-state Lambda hyperons in deep- inelastic scattering have been studied, results of which will be presented in this contribution.

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Contributing Institute(s):

1. HERMES Kollaboration (HERMES)

Research Program(s):

1. 611 - Fundamental Particles and Forces (POF4-611) (POF4-611)

Experiment(s):

1. HERA: HERMES

Appears in the scientific report 2025

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