Semi-inclusive π0 target and beam-target asymmetries from 6 GeV electron scattering with CLAS

2017/09/30 by S. S. Jawalkar, S. Jawalkar, S. Koirala +171
Physics and Astronomy · #Deep inelastic scattering #Electron #Gluon #Hadron #High-Energy Particle Collisions Research #Inelastic scattering #Lepton #Nuclear physics #Nucleon #Particle physics #Particle physics theoretical and experimental studies #Physics #Pion #Quantum Chromodynamics and Particle Interactions #Quark #Scattering #Spin (aerodynamics) #hep-ph #nucl-ex

paper · pdf · doi:10.1016/j.physletb.2018.06.014

18 preprint pages, 3 figures

arxiv created 2018/04/24 · openalex publication_date 2018/06/14 · arxiv updated 2018/06/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/02

Abstract

We present precision measurements of the target and beam-target spin asymmetries from neutral pion electroproduction in deep-inelastic scattering (DIS) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. We scattered 6-GeV, longitudinally polarized electrons off longitudinally polarized protons in a cryogenic 14NH3 target, and extracted double and single target spin asymmetries for ep→e′π0X in multidimensional bins in four-momentum transfer (1.0<Q2<3.2 GeV2), Bjorken-x (0.12<x<0.48), hadron energy fraction (0.4<z<0.7), transverse pion momentum (0<PT<1.0 GeV), and azimuthal angle ϕh between the lepton scattering and hadron production planes. We extracted asymmetries as a function of both x and PT, which provide access to transverse-momentum distributions of longitudinally polarized quarks. The double spin asymmetries depend weakly on PT. The sin⁡2ϕh moments are zero within uncertainties, which is consistent with the expected suppression of the Collins fragmentation function. The observed sin⁡ϕh moments suggest that quark gluon correlations are significant at large x.

Citations

• Fragmentation of transversely polarized quarks probed in transverse momentum distributions
• Lowest order QED radiative corrections to five-fold differential cross section of hadron leptoproduction
• Effects of transversity in deep-inelastic scattering by polarized protons
• Transverse momentum dependence of the quark helicity distributions and the Cahn effect in double-spin asymmetryALLin semiinclusive DIS
• Reanalysis of azimuthal spin asymmetries of meson electroproduction
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• Single-spin production asymmetries from the hard scattering of pointlike constituents
• Empirical Fit to electron-nucleus scattering
• Measurement of Azimuthal Asymmetries in Inclusive Production of Hadron Pairs ine+e−Annihilation at Belle