We study the beam-normal single-spin asymmetry (BNSSA) in high-energy elastic electron scattering from several spin-0 nuclei. Existing theoretical approaches work in the plane-wave formalism and predict the BNSSA to scale as ∼ A /Z with the atomic number Z and nuclear mass number A . While this prediction holds for light and intermediate nuclei, a striking disagreement in both the sign and the magnitude of BNSSA was observed by the PREX collaboration for 208 Pb , coined the “PREX puzzle.” To shed light on this disagreement, we go beyond the plane-wave approach which neglects Coulomb distortions known to be significant for heavy nuclei. We explicitly investigate the dependence of BNSSA on A and Z by (i) including inelastic intermediate states' contributions into the Coulomb problem in the form of an optical potential, (ii) by accounting for the experimental information on the A -dependence of the Compton slope parameter, and (iii) giving a thorough account of the uncertainties of the calculation. Despite of these improvements, the PREX puzzle remains unexplained. We discuss further strategies to resolve this riddle.
Beam-normal single-spin asymmetry in elastic scattering of electrons from a spin-0 nucleus / O. Koshchii, M. Gorchtein, X. Roca-Maza, H. Spiesberger. - In: PHYSICAL REVIEW C. - ISSN 2469-9985. - 103:6(2021 Jun 15), pp. 064316.1-064316.12.
|Titolo:||Beam-normal single-spin asymmetry in elastic scattering of electrons from a spin-0 nucleus|
|Settore Scientifico Disciplinare:||Settore FIS/04 - Fisica Nucleare e Subnucleare|
|Data di pubblicazione:||15-giu-2021|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1103/PhysRevC.103.064316|
|Appare nelle tipologie:||01 - Articolo su periodico|