Charged-Pion cross sections and double-helicity asymmetries in polarized p+p collisions at √s = 200 GeV Article

Adare, A, Aidala, C, Ajitanand, NN et al. (2015). Charged-Pion cross sections and double-helicity asymmetries in polarized p+p collisions at √s = 200 GeV . PHYSICAL REVIEW D, 91(3), 10.1103/PhysRevD.91.032001

cited authors

  • Adare, A; Aidala, C; Ajitanand, NN; Akiba, Y; Akimoto, R; Al-Ta’ani, H; Alexander, J; Andrews, KR; Angerami, A; Aoki, K; Apadula, N; Appelt, E; Aramaki, Y; Armendariz, R; Aschenauer, EC; Atomssa, ET; Awes, TC; Azmoun, B; Babintsev, V; Bai, M; Bannier, B; Barish, KN; Bassalleck, B; Basye, AT; Bathe, S; Baublis, V; Baumann, C; Bazilevsky, A; Belmont, R; Ben-Benjamin, J; Bennett, R; Blau, DS; Bok, JS; Boyle, K; Brooks, ML; Broxmeyer, D; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Campbell, S; Castera, P; Chen, CH; Chi, CY; Chiu, M; Choi, IJ; Choi, JB; Choudhury, RK; Christiansen, P; Chujo, T; Chvala, O; Cianciolo, V; Citron, Z; Cole, BA; Conesadelvalle, Z; Connors, M; Csanád, M; Csörgő, T; Dairaku, S; Datta, A; David, G; Dayananda, MK; Denisov, A; Deshpande, A; Desmond, EJ; Dharmawardane, KV; Dietzsch, O; Dion, A; Donadelli, M; Drapier, O; Drees, A; Drees, KA; Durham, JM; Durum, A; D’Orazio, L; Efremenko, YV; Engelmore, T; Enokizono, A; En’Yo, H; Esumi, S; Fadem, B; Fields, DE; Finger, M; Finger, M; Fleuret, F; Fokin, SL; Frantz, JE; Franz, A; Frawley, AD; Fukao, Y; Fusayasu, T; Gal, C; Garishvili, I; Giordano, F; Glenn, A; Gong, X; Gonin, M; Goto, Y; Decassagnac, RG; Grau, N

authors

abstract

  • We present midrapidity charged-pion invariant cross sections, the ratio of the π- to π+ cross sections and the charge-separated double-spin asymmetries in polarized p + p collisions at p√s = 200 GeV. While the cross section measurements are consistent within the errors of next-to-leading-order (NLO) perturbative quantum chromodynamics predictions (pQCD), the same calculations overestimate the ratio of the charged-pion cross sections. This discrepancy arises from the cancellation of the substantial systematic errors associated with the NLO-pQCD predictions in the ratio and highlights the constraints these data will place on flavor-dependent pion fragmentation functions. The charge-separated pion asymmetries presented here sample an x range of ~0.03-0.16 and provide unique information on the sign of the gluon-helicity distribution.

publication date

  • January 1, 2015

published in

Digital Object Identifier (DOI)

volume

  • 91

issue

  • 3