Jul 6 – 13, 2022
Bologna, Italy
Europe/Rome timezone

Latest Hermes results on azimuthal single- and double-spin asymmetries in semi-inclusive deep-inelastic scattering by transversely polarized protons

Jul 9, 2022, 9:45 AM
Room 1 (Europa Auditorium)

Room 1 (Europa Auditorium)

Parallel Talk Strong interactions and Hadron Physics Strong interactions and Hadron Physics


Luciano Libero Pappalardo (Istituto Nazionale di Fisica Nucleare)


Azimuthal single- and double-spin asymmetries measured at Hermes in semi-inclusive leptoproduction of pions, charged kaons, protons, and antiprotons from a transversely polarized hydrogen target are presented. The results of a re-analysis of the previously published Collins and Sivers asymmetries, extended to include protons and antiprotons as well as an extraction in a multi-dimensional binning and enlarged phase space, is reported along with the corresponding results for the remaining single- and double-spin asymmetries associated to the semi-inclusive deep-inelastic scattering process with a transversely polarized target. Among those results, significant non-vanishing ${\rm cos}⁡(ϕ-ϕ_s)$ modulations provide evidence for a sizable worm-gear distribution $g_{1T}$. Most of the other modulations are found to be consistent with zero with the notable exception of large ${\rm sin}(⁡ϕ_s)$ modulations for charged pions and positively charged kaons.

In-person participation No

Primary author

Luciano Libero Pappalardo (Istituto Nazionale di Fisica Nucleare)

Presentation materials