Precise measurements of beam spin asymmetries in semi-inclusive π0 production

• DOI: 10.1016/j.physletb.2011.09.044
• Publication Date: 2011-09-17T21:25:18Z
• Authors: M. Aghasyan; H. Avakian; P. Rossi; E. De Sanctis; D. Hasch; M. Mirazita; D. Adikaram; M.J. Amaryan; M. Anghinolfi; H. Baghdasaryan; J. Ball; M. Battaglieri; V. Batourine; I. Bedlinskiy; R.P. Bennett; A.S. Biselli; D. Branford; W.J. Briscoe; S. Bültmann; V.D. Burkert; D.S. Carman; S. Chandavar; P.L. Cole; P. Collins; M. Contalbrigo; V. Crede; A. DʼAngelo; A. Daniel; N. Dashyan; R. De Vita; A. Deur; B. Dey; R. Dickson; C. Djalali; G.E. Dodge; D. Doughty; R. Dupre; H. Egiyan; A. El Alaoui; L. Elouadrhiri; P. Eugenio; G. Fedotov; S. Fegan; A. Fradi; M.Y. Gabrielyan; M. Garçon; N. Gevorgyan; G.P. Gilfoyle; K.L. Giovanetti; F.X. Girod; J.T. Goetz; W. Gohn; E. Golovatch; R.W. Gothe; L. Graham; K.A. Griffioen; B. Guegan; M. Guidal; N. Guler; L. Guo; K. Hafidi; C. Hanretty; K. Hicks; M. Holtrop; C.E. Hyde; Y. Ilieva; D.G. Ireland; E.L. Isupov; S.S. Jawalkar; D. Jenkins; H.S. Jo; K. Joo; D. Keller; M. Khandaker; P. Khetarpal; A. Kim; W. Kim; A. Klein; F.J. Klein; V. Kubarovsky; S.E. Kuhn; S.V. Kuleshov; V. Kuznetsov; N.D. Kvaltine; K. Livingston; H.Y. Lu; I.J.D. MacGregor; N. Markov; M. Mayer; J. McAndrew; B. McKinnon; C.A. Meyer; A.M. Micherdzinska; V. Mokeev; B. Moreno; H. Moutarde; E. Munevar; P. Nadel-Turonski; A. Ni; S. Niccolai; G. Niculescu; I. Niculescu; M. Osipenko; A.I. Ostrovidov; M. Paolone; L. Pappalardo; R. Paremuzyan; K. Park; S. Park; E. Pasyuk; S. Anefalos Pereira; E. Phelps; S. Pisano; O. Pogorelko; S. Pozdniakov; J.W. Price; S. Procureur; Y. Prok; D. Protopopescu; B.A. Raue; G. Ricco; D. Rimal; M. Ripani; G. Rosner; F. Sabatié; M.S. Saini; C. Salgado; D. Schott; R.A. Schumacher; E. Seder; H. Seraydaryan; Y.G. Sharabian; G.D. Smith; D.I. Sober; S.S. Stepanyan; S. Stepanyan; P. Stoler; I. Strakovsky; S. Strauch; M. Taiuti; W. Tang; C.E. Taylor; S. Tkachenko; M. Ungaro; H. Voskanyan; E. Voutier; D. Watts; L.B. Weinstein; D.P. Weygand; M.H. Wood; L. Zana; J. Zhang; B. Zhao; Z.W. Zhao
• Keywords: Astrophysics and Astronomy; Settore FIS/04 - FISICA NUCLEARE E SUBNUCLEARE; Nuclear and High Energy Physics; DEEP-INELASTIC SCATTERING; FINAL-STATE INTERACTIONS; PION ELECTROPRODUCTION; PARTON DISTRIBUTIONS; DRELL-YAN; LEPTOPRODUCTION; DEPENDENCE; DRELL-YAN; FOS: Physical sciences; 530; 01 natural sciences; Leptoproduction; High Energy Physics - Experiment; DEEP-INELASTIC SCATTERING; High Energy Physics - Experiment (hep-ex); LEPTOPRODUCTION; DEPENDENCE; 0103 physical sciences; Physical Sciences and Mathematics; [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]; Nuclear; PION ELECTROPRODUCTION; QC; FINAL-STATE INTERACTIONS; /dk/atira/pure/subjectarea/asjc/3100/3106; Physics; Pion electroproduction; Final state interactions; Elementary Particles and Fields and String Theory; Parton distribution; PARTON DISTRIBUTIONS; Deep inelastic scattering

We present studies of single-spin asymmetries for neutral pion electroproduction in semi-inclusive deep-inelastic scattering of 5.776 GeV polarized electrons from an unpolarized hydrogen target, using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. A substantial $\sin ��_h$ amplitude has been measured in the distribution of the cross section asymmetry as a function of the azimuthal angle $��_h$ of the produced neutral pion. The dependence of this amplitude on Bjorken $x$ and on the pion transverse momentum is extracted with significantly higher precision than previous data and is compared to model calculations.<br/>to be submitted PLB<br/>