Precise measurements of beam spin asymmetries in semi-inclusive pi super(0) production

• Published in: Physics letters. B Vol. 704; no. 5; pp. 397 - 402
• Main Authors: Aghasyan, M, Avakian, H, De Sanctis, E, Hasch, D, Mirazita, M, Adikaram, D, Amaryan, MJ, Ball, J, Battaglieri, M, Batourine, V, Bedlinskiy, I, Bennett, R P, Biselli, A S, Briscoe, W J, Bueltmann, S, Burkert, V D, Carman, D S, Chandavar, S, Cole, P L, Collins, P, D'Angelo, A, Daniel, A, De Vita, R, Deur, A, Dey, B, Djalali, C, Dodge, GE, Doughty, D, Egiyan, H, El Alaoui, A, Fedotov, G, Fegan, S, Fradi, A, Gabrielyan, MY, Garcon, M, Gevorgyan, N, Giovanetti, K L, Girod, F X, Gohn, W, Golovatch, E, Gothe, R W, Griffioen, KA, Guegan, B, Holtrop, M, Ilieva, Y, Ireland, D G, Isupov, EL, Jo, H S, Keller, D, Khandaker, M, Kim, W, Klein, F J, Kubarovsky, V, Kuhn, SE, Kuznetsov, V, Kvaltine, N D, Livingston, K, Lu, HY, MacGregor, IJD, Markov, N, Mayer, M, McKinnon, B, Meyer, CA, Moreno, B, Moutarde, H, Munevar, E, Nadel-Turonski, P, Ni, A, Niculescu, I, Paolone, M, Paremuzyan, R, Park, K, Park, S, Pasyuk, E, Pereira, SAnefalos, Phelps, E, Pisano, S, Pozdniakov, S, Procureur, S, Prok, Y, Protopopescu, D, Raue, BA, Ricco, G, Rimal, D, Saini, MS, Schumacher, R A, Seraydaryan, H, Sharabian, Y G, Sober, DI, Stepanyan, S S, Stoler, P, Strauch, S, Tang, W, Ungaro, M, Voskanyan, H, Voutier, E, Watts, D, Weinstein, L B, Weygand, D P, Wood, M H
• Format: Journal Article
• Language: English
• Published: 25.10.2011
• Subjects: Amplitudes; Asymmetry; Beams (radiation); Cross sections; Elementary particles; Mathematical models; Pions
• ISSN: 0370-2693
• DOI: 10.1016/j.physletb.2011.09.044

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 [inline image] amplitude has been measured in the distribution of the cross section asymmetry as a function of the azimuthal angle phi 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.