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Full-Text Articles in Astrophysics and Astronomy

Precision Measurements Of Aⁿ1 In The Deep Inelastic Regime, D. S. Parno, D. Flay, M. Posik, M. Canan, C. Hyde, The Jefferson Lab Hall A Collaboration Jan 2015

Precision Measurements Of Aⁿ1 In The Deep Inelastic Regime, D. S. Parno, D. Flay, M. Posik, M. Canan, C. Hyde, The Jefferson Lab Hall A Collaboration

Physics Faculty Publications

We have performed precision measurements of the double-spin virtual-photon asymmetry A1 on the neutron in the deep inelastic scattering regime, using an open-geometry, large-acceptance spectrometer and a longitudinally and transversely polarized 3He target. Our data cover a wide kinematic range 0.277 <= x <= 0.548 at an average Q2 value of 3.078(GeV/c)2, doubling the available high-precision neutron data in this xrange. We have combined our results with world data on proton targets to make a leading-order extraction of the ratio of polarized-to-unpolarized parton distribution functions for up quarks and for down quarks in the same kinematic range. Our data are consistent with …


First Measurement Of The Polarization Observable E In The P→ (Ɣ→, Π+) In Reaction Up To 2.25 Gev, S. Strauch, W. J. Briscoe, M. Döring, E. Klempt, V. A. Nikonov, E. Pasyuk, D. Rönchen, A.V. Sarantsev, I. Strakovsky, R. Workman, K. P. Adhikari, D. Adikaram, L. El Fassi Jan 2015

First Measurement Of The Polarization Observable E In The P→ (Ɣ→, Π+) In Reaction Up To 2.25 Gev, S. Strauch, W. J. Briscoe, M. Döring, E. Klempt, V. A. Nikonov, E. Pasyuk, D. Rönchen, A.V. Sarantsev, I. Strakovsky, R. Workman, K. P. Adhikari, D. Adikaram, L. El Fassi

Physics Faculty Publications

First results from the longitudinally polarized frozen-spin target (FROST) program are reported. The double-polarization observable E, for the reaction ɣp→π+n, has been measured using a circularly polarized tagged-photon beam, with energies from 0.35 to 2.37 GeV. The final-state pions were detected with the CEBAF Large Acceptance Spectrometer in Hall B at the Thomas Jefferson National Accelerator Facility. These polarization data agree fairly well with previous partial-wave analyses at low photon energies. Over much of the covered energy range, however, significant deviations are observed, particularly in the high-energy region where high-L multipoles contribute. The data have been …