Target and double spin asymmetries of deeply virtual π0 production with a longitudinally polarized proton target and CLAS

• DOI: 10.1016/j.physletb.2017.02.032
• Publication Date: 2017-02-23T01:48:15Z
• Authors: A. Kim; H. Avakian; V. Burkert; K. Joo; W. Kim; K.P. Adhikari; Z. Akbar; S. Anefalos Pereira; R.A. Badui; M. Battaglieri; V. Batourine; I. Bedlinskiy; A.S. Biselli; S. Boiarinov; P. Bosted; W.J. Briscoe; W.K. Brooks; S. Bültmann; T. Cao; D.S. Carman; A. Celentano; S. Chandavar; G. Charles; T. Chetry; L. Colaneri; P.L. Cole; N. Compton; M. Contalbrigo; O. Cortes; V. Crede; A. D'Angelo; N. Dashyan; R. De Vita; E. De Sanctis; C. Djalali; H. Egiyan; A. El Alaoui; L. El Fassi; P. Eugenio; G. Fedotov; R. Fersch; A. Filippi; J.A. Fleming; A. Fradi; M. Garc con; Y. Ghandilyan; G.P. Gilfoyle; K.L. Giovanetti; F.X. Girod; W. Gohn; E. Golovatch; R.W. Gothe; K.A. Griffioen; L. Guo; K. Hafidi; C. Hanretty; M. Hattawy; D. Heddle; K. Hicks; M. Holtrop; Y. Ilieva; D.G. Ireland; B.S. Ishkhanov; D. Jenkins; H. Jiang; H.S. Jo; S. Joosten; D. Keller; G. Khachatryan; M. Khandaker; A. Klein; F.J. Klein; V. Kubarovsky; S.E. Kuhn; S.V. Kuleshov; L. Lanza; P. Lenisa; H.Y. Lu; I.J.D. MacGregor; N. Markov; P. Mattione; M.E. McCracken; B. McKinnon; V. Mokeev; A. Movsisyan; E. Munevar; P. Nadel-Turonski; L.A. Net; S. Niccolai; M. Osipenko; A.I. Ostrovidov; M. Paolone; K. Park; E. Pasyuk; W. Phelps; S. Pisano; O. Pogorelko; J.W. Price; Y. Prok; M. Ripani; A. Rizzo; G. Rosner; P. Rossi; P. Roy; C. Salgado; R.A. Schumacher; E. Seder; Y.G. Sharabian; Iu. Skorodumina; G.D. Smith; D. Sokhan; N. Sparveris; S. Stepanyan; P. Stoler; I.I. Strakovsky; S. Strauch; V. Sytnik; M. Taiuti; B. Torayev; M. Ungaro; H. Voskanyan; E. Voutier; D.P. Watts; X. Wei; L.B. Weinstein; N. Zachariou; L. Zana; J. Zhang
• Keywords: Settore FIS/04 - FISICA NUCLEARE E SUBNUCLEARE; Astrophysics and Astronomy; Nuclear and High Energy Physics; Deeply Virtual Meson Production; QC1-999; FOS: Physical sciences; [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]; 530; 01 natural sciences; Nucleon structure; Chiral-odd generalized parton distributions; CLAS collaboration; Deeply Virtual Meson Production; Longitudinally polarized target; Nucleon structure; Nuclear and High Energy Physics; 0103 physical sciences; Physical Sciences and Mathematics; Nuclear; Nuclear Experiment (nucl-ex); Generalized parton distributions; Nuclear Experiment; Chiral-odd generalized parton distribution; Physics; Longitudinally polarized target; Nucleon structure; CLAS collaboration; Deeply Virtual Meson Production; Chiral-odd generalized parton distributions; Longitudinally polarized target; Transversity; Chiral-odd generalized parton distributions; CLAS collaboration; Compton scattering

The target and double spin asymmetries of the exclusive pseudoscalar channel $\vec e\vec p\to ep��^0$ were measured for the first time in the deep-inelastic regime using a longitudinally polarized 5.9 GeV electron beam and a longitudinally polarized proton target at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS). The data were collected over a large kinematic phase space and divided into 110 four-dimensional bins of $Q^2$, $x_B$, $-t$ and $��$. Large values of asymmetry moments clearly indicate a substantial contribution to the polarized structure functions from transverse virtual photon amplitudes. The interpretation of experimental data in terms of generalized parton distributions (GPDs) provides the first insight on the chiral-odd GPDs $\tilde{H}_T$ and $E_T$, and complement previous measurements of unpolarized structure functions sensitive to the GPDs $H_T$ and $\bar E_T$. These data provide necessary constraints for chiral-odd GPD parametrizations and will strongly influence existing theoretical handbag models.