Oliver Thewalt

    Oliver Thewalt

    Theoretical Physics | Quantum Biology | Dark Matter Research | Energy Consulting | Creation of Hydrogen ATOM in the Higgs Field >> Vote for Nobel Prize

    A view of the colorful microcosm within a proton

    http://phys.org/news/2016-03-view-microcosm-proton.html

    Measurement of the transverse single-spin asymmetry in p↑+p→W±/Z0 at RHIC

     

    STAR Collaboration: L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, A. Aparin, D. Arkhipkin, E. C. Aschenauer, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, A. Banerjee, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, I. Bunzarov, J. Butterworth, H. Caines, M. Calderón de la Barca Sánchez, J. M. Campbell, D. Cebra, I. Chakaberia, P. Chaloupka, Z. Chang, S. Chattopadhyay, J. H. Chen, X. Chen, J. Cheng, M. Cherney, W. Christie, G. Contin, H. J. Crawford, S. Das, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, A. A. Derevschikov, B. di Ruzza, L. Didenko, C. Dilks, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, L. E. Dunkelberger, et al. (280 additional authors not shown)

    (Submitted on 18 Nov 2015 (v1), last revised 19 Feb 2016 (this version, v2))


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    We present the measurement of the transverse single-spin asymmetry of weak boson production in transversely polarized proton-proton collisions at s√=500 GeV by the STAR experiment at RHIC. The measured observable is sensitive to the Sivers function, one of the transverse momentum dependent parton distribution functions, which is predicted to have the opposite sign in proton-proton collisions from that observed in deep inelastic lepton-proton scattering. These data provide the first experimental investigation of the non-universality of the Sivers function, fundamental to our understanding of QCD.