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We report measurements of target- and double-spin asymmetries for the exclusive channel ⃗e⃗p→eπ+(n) in the nucleon resonance region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). These asymmetries were extracted from data obtained using a longitudinally polarized NH3 target and a longitudinally polarized electron beam with energies 1.1, 1.3, 2.0, 2.3, and 3.0 GeV. The new results are consistent with previous CLAS publications but are extended to a low Q2 range from 0.0065 to 0.35(GeV/c)2. The Q2 access was made possible by a custom-built Cherenkov detector that allowed the detection of electrons for scattering angles as low as 6∘. These results are compared with the unitary isobar models JANR and MAID, the partial-wave analysis prediction from SAID, and the dynamic model DMT. In many kinematic regions our results, in particular results on the target asymmetry, help to constrain the polarization-dependent components of these models.


Copyright 2016 American Physical Society

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Physical Review C

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Zheng X, Adhikari KP, Bosted P, Deur A, Drozdov V, El Fassi L, Kang H, Kovacs K, Kuhn S, Long E, Phillips SK., Biselli, Angela, et al [CLAS Collaboration]. "Measurement of target and double-spin asymmetries for the e ⃗ p ⃗→ e π+(n) reaction in the nucleon resonance region at low Q 2." Physical Review C 94, no. 4 (2016): 045206.


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