Multidimensional, High Precision Measurements of Beam Single Spin Asymmetries in Semi-inclusive π+ Electroproduction off Protons in the Valence Region

(CLAS Collaboration)

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High precision measurements of the polarized electron beam-spin asymmetry in semi-inclusive deep inelastic scattering (SIDIS) from the proton have been performed using a 10.6 GeV incident electron beam and the CLAS12 spectrometer at Jefferson Lab. We report here a high precision multidimensional study of single π+ SIDIS data over a large kinematic range in Bjorken x, fractional energy, and transverse momentum of the hadron as well as photon virtualities Q2 ranging from 1-7 GeV2. In particular, the structure function ratio FLUsinφ/FUU has been determined, where FLUsinφ is a twist-3 quantity that can reveal novel aspects of emergent hadron mass and quark-gluon correlations within the nucleon. The data's impact on the evolving understanding of the underlying reaction mechanisms and their kinematic variation is explored using theoretical models for the different contributing transverse momentum dependent parton distribution functions.

Original languageEnglish
Article number062005
Number of pages7
JournalPhysical Review Letters
Issue number6
Publication statusPublished - 11 Feb 2022

Bibliographical note

Funding Information:
We acknowledge the outstanding efforts of the staff of the Accelerator and the Physics Divisions at Jefferson Lab in making this experiment possible. We owe much gratitude to P. Schweitzer for many fruitful discussions concerning the interpretation of our results. This work was supported in part by the U.S. Department of Energy, the National Science Foundation (NSF), the Italian Istituto Nazionale di Fisica Nucleare (INFN), the French Centre National de la Recherche Scientifique (CNRS), the French Commissariat pour l’Energie Atomique, the U.K. Science and Technology Facilities Council, the National Research Foundation (NRF) of Korea, the Helmholtz-Forschungsakademie Hessen für FAIR (HFHF), the Ministry of Science and Higher Education of the Russian Federation and the National Natural Science Foundation of China. The Southeastern Universities Research Association (SURA) operates the Thomas Jefferson National Accelerator Facility for the U.S. Department of Energy under Contract No. DE-AC05-06OR23177.

Publisher Copyright:
© 2022 authors. Published by the American Physical Society.

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