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تسجيل مستخدم جديدSingle Spin Asymmetries in Charged Pion Production from Semi-Inclusive Deep Inelastic Scattering on a Transversely Polarized $^3$He Target
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We report the first measurement of target single spin asymmetries in the semi-inclusive $^3{He}(e,epi^pm)X$ reaction on a transversely polarized target. The experiment, conducted at Jefferson Lab using a 5.9 GeV electron beam, covers a range of 0.14 $< x <$ 0.34 with 1.3 $<Q^2<$ 2.7 GeV$^2$. The Collins and Sivers moments were extracted from the azimuthal angular dependence of the measured asymmetries. The extracted $pi^pm$ Collins moments for $^3$He are consistent with zero, except for the $pi^+$ moment at $x=0.34$, which deviates from zero by 2.3$sigma$. While the $pi^-$ Sivers moments are consistent with zero, the $pi^+$ Sivers moments favor negative values. The neutron results were extracted using the nucleon effective polarization and the measured cross section ratio of proton to $^3$He, and are largely consistent with the predictions of phenomenological fits and quark model calculations.
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