Beam-spin asymmetries from semi-inclusive pion electroproduction

Abstract

We have measured the moment $A_{LU}^{\sin \varphi }$ corresponding to the polarized electron beam-spin asymmetry in SIDIS. $A_{LU}^{\sin \varphi }$ is a twist-3 quantity providing information about quark-gluon correlations. Data were taken with the CLAS Spectrometer at Jefferson Lab using a 5.498 GeV longitudinally polarized electron beam and an unpolarized liquid hydrogen target. All three pion channels (${\pi }^{+}$, ${\pi }^0$ and ${\pi }^{-}$) were measured simultaneously over a large range of kinematics within the virtuality range $Q^2\approx$ 1.0-4.5 GeV${}^2$. The observable was measured with better than 1% statistical precision over a large range of $z$, $P_T$, $x_B$, and $Q^2$, which permits comparison with several reaction models. The discussed measurements provide an upgrade in statistics over previous measurements, and serve as the first evidence for the negative sign of the ${\pi }^{-}$ $\sin \varphi$ moment.

16 pages, 18 figures

References in corpus (13)

• Extraction of Spin-Dependent Parton Densities and Their Uncertainties
• Transverse-momentum distributions in a diquark spectator model
• Measurement of Azimuthal Asymmetries in Inclusive Production of Hadron Pairs in e+e- Annihilation at \sqrt{s} = 10.58 GeV
• Experimental investigation of transverse spin asymmetries in muon-p SIDIS processes: Sivers asymmetries
• The transverse momentum dependent distribution functions in the bag model
• Experimental investigation of transverse spin asymmetries in muon-p SIDIS processes: Collins asymmetries
• Unified framework for generalized and transverse-momentum dependent parton distributions within a 3Q light-cone picture of the nucleon
• Twist analysis of the nucleon spin in QCD
• Collins effect in semi-inclusive deeply inelastic scattering and in electron positron annihilation
• Probing Parton Orbital Angular Momentum in Longitudinally Polarized Nucleon
• Naive time-reversal odd phenomena in semi-inclusive deep-inelastic scattering from light-cone constituent quark models
• Beam Spin Asymmetries of Charged and Neutral Pion Productions in Semi-inclusive DIS
• Beam single spin asymmetry of neutral pion production in semi-inclusive deep inelastic scattering

Cited by in corpus (12)

• Diquark Correlations in Hadron Physics: Origin, Impact and Evidence
• Semi-Inclusive Deep Inelastic Scattering in Wandzura-Wilczek-type approximation
• The role of zero-mode contributions in the matching for the twist-3 PDFs $e(x)$ and $h_L(x)$
• Where do we stand with a 3-D picture of the proton?
• Transverse single-spin asymmetries of pion production in semi-inclusive DIS at subleading twist
• Twist-3 T-odd fragmentation functions $G^{\perp }$ and ${\tilde{G}}^{\perp }$ in a spectator model
• Beam-helicity asymmetries for single-hadron production in semi-inclusive deep-inelastic scattering from unpolarized hydrogen and deuterium targets
• Beam spin asymmetry in semi-inclusive electroproduction of a hadron pair
• Double Spin Asymmetries $A_{LT}^{\cos {\varphi }_S}$ and $A_{LT}^{\cos (2{\varphi }_h-{\varphi }_S)}$ in semi-inclusive DIS
• Single-spin asymmetries in electroproduction of pions on the longitudinally polarized nucleon targets
• Spin Orbit Correlations and the Structure of the Nucleon
• The cos${\varphi }_R$ asymmetry of dihadron production in double longitudinally polarized SIDIS