We report measurements of single- and double-spin asymmetries for W± and Z/γ* boson production in longitudinally polarized p+p collisions at s=510  GeV by the STAR experiment at RHIC. The asymmetries for W± were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton’s polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05<0.2.

Measurement of longitudinal spin asymmetries for weak boson production in polarized proton-proton collisions at RHIC / Adamczyk, L., Adkins, J.K., Agakishiev, G., Aggarwal, M.M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C.D., Aparin, A., Arkhipkin, D., Aschenauer, E.C., Averichev, G.S., Balewski, J., Banerjee, A., Beavis, D.R., Bellwied, R., Bhasin, A., Bhati, A.K., Bhattarai, P., Bichsel, H., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 113:7(2014), pp. 072301.1-072301.7. [10.1103/PhysRevLett.113.072301]

Measurement of longitudinal spin asymmetries for weak boson production in polarized proton-proton collisions at RHIC

Contin, G.;Di Ruzza, B.;
2014-01-01

Abstract

We report measurements of single- and double-spin asymmetries for W± and Z/γ* boson production in longitudinally polarized p+p collisions at s=510  GeV by the STAR experiment at RHIC. The asymmetries for W± were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton’s polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05<0.2.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11368/2946265
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