@article{02858002dc014c8a9dd577c96a6b2b32,
title = "Observation of Beam Spin Asymmetries in the Process ep →e′π+π-X with CLAS12",
abstract = "The observation of beam spin asymmetries in two-pion production in semi-inclusive deep inelastic scattering off an unpolarized proton target is reported. The data presented here were taken in the fall of 2018 with the CLAS12 spectrometer using a 10.6 GeV longitudinally spin-polarized electron beam delivered by CEBAF at JLab. The measured asymmetries provide the first opportunity to extract the parton distribution function e(x), which provides information about the interaction between gluons and quarks, in a collinear framework that offers cleaner access than previous measurements. The asymmetries also constitute the first ever signal sensitive to the helicity-dependent two-pion fragmentation function G1. A clear sign change is observed around the ρ mass that appears in model calculations and is indicative of the dependence of the produced pions on the helicity of the fragmenting quark.",
author = "{(CLAS Collaboration)} and Hayward, {T. B.} and C. Dilks and A. Vossen and H. Avakian and S. Adhikari and G. Angelini and M. Arratia and H. Atac and {Ayerbe Gayoso}, C. and Baltzell, {N. A.} and L. Barion and M. Battaglieri and I. Bedlinskiy and F. Benmokhtar and A. Bianconi and Biselli, {A. S.} and M. Bond{\`i} and F. Boss{\`u} and S. Boiarinov and Briscoe, {W. J.} and Brooks, {W. K.} and D. Bulumulla and Burkert, {V. D.} and Carman, {D. S.} and Carvajal, {J. C.} and A. Celentano and P. Chatagnon and T. Chetry and G. Ciullo and Clary, {B. A.} and Cole, {P. L.} and M. Contalbrigo and G. Costantini and V. Crede and A. D'Angelo and N. Dashyan and {De Vita}, R. and M. Defurne and A. Deur and S. Diehl and C. Djalali and R. Dupre and M. Dugger and H. Egiyan and M. Ehrhart and {El Alaoui}, A. and {El Fassi}, L. and L. Elouadrhiri and S. Fegan and A. Filippi",
note = "Publisher Copyright: {\textcopyright} 2021 authors. Published by the American Physical Society.",
year = "2021",
month = apr,
day = "12",
doi = "10.1103/PhysRevLett.126.152501",
language = "English (US)",
volume = "126",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "15",
}