Polarization effects in pion electroproduction from 3He

Inelastic electron scattering from 3He is studied in the kinematic region of pion production. Inclusive processes with polarization of the electron probe and of the 3He target are described in the plane wave impulse approximation. The question to what extent polarized 3He can serve in this kinematic regime as a substitute for unavailable neutron spin targets is discussed

Polarized deep-inelastic lepton scattering from the polarized two- and three-nucleon bound states

A relativistic description of polarized deep-inelastic lepton scattering from polarized nuclei is presented. It is based on front form dynamics. Convolution formulas for the nuclear spin structure functions gA1 and gA2 are derived. They require the front form spin distributions of nuclei and the nucleonic spin structure functions. The description is applied to the deuteron and the trinucleon bound states. The numerical calculations show that relativistic effects arising from the consistent quantum mechanical treatment of spin are small. Simple approximations to the convolution formulas for gA1 and gA2 are justified. The approximative convolution formulas allow the subtraction of nuclear effects from measured spin structure functions and therefore the experimental determination of the neutron spin structure functions. Polarized 3He turns out to be a rather reliable effective neutron spin target for deep-inelastic scattering of polarized leptons. The differences between descriptions based on front form and on instant form dynamics are also discussed

Das avós: O arquivo fotográfico oitocentista na prática imagética de Rosana Paulino

From the photographic archive of Imperial Brazil, the artist Rosana Paulino recovers images taken of black women which are marked by racist exploitation. Focusing on representations of wet nurses, this article analyses Paulino’s imagetic practices with which she transforms visual regimes based on slavocrat violence into affective conviviality, particularly in the photographic ritual of the video work Das avós. Tracing the contexts and characteristics of the reconfigured photographs, including the discourse on certain images, the article shows how Rosana Paulino reveals the wounds of transgenerational trauma and, at the same time, symbolically recreates a genealogy interrupted by the necropolitics existing in Brazil since the time of slavery.A partir do arquivo fotográfico do Brasil Imperial, a artista Rosana Paulino resgata imagens de mulheres negras, marcadas pela exploração racista. Com foco nas representações de amas de leite, este artigo analisa as práticas imagéticas de Paulino com as quais transforma regimes visuais baseados na violência escravocrata em uma convivialidade afetiva, particularmente no ritual fotográfico do vídeo Das avós. Traçando os contextos e características das fotografias reconfiguradas, inclusive o discurso sobre certas imagens, o artigo mostra como Rosana Paulino revela as feridas do trauma transgeracional e, ao mesmo tempo, recria simbolicamente uma genealogia interrompida pela necropolítica em vigor no Brasil desde a época da escravidão