The Measurement of Transverse Single Spin Asymmetry of Forward Charged Hadrons in the PHENIX experiment at RHIC

ORAL

Abstract

The measurement of transverse single spin asymmetries provides an opportunity to probe the parton structure of transversely polarized nucleons. We present PHENIX preliminary results of transverse single spin asymmetries of non-identified charged hadrons measured in the muon spectrometers (1.2 $< \eta <$ 2.5) from transversely polarized p+p collisions at $\sqrt{s}=200$GeV as a function of $x_{F}$ and $p_{T}$. PHENIX has lower $x_{F}$ and higher $p_{T}$ coverage than the Brahms experiment, which has made these measurements in the past. At lower $x_{F}$ we can study the turn-on of the asymmetry as a function of $x_{F}$, and the crossover region between pQCD and TMD factorization is at higher $p_{T}$. Perturbative QCD predicts that the asymmetry should decrease as 1/$p_{T}$. For this purpose we also show the $p_{T}$ dependent asymmetry in a very narrow $x_{F}$ range around the turn-on region.

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Authors

  • Michael Turner

    Illinois Institute of Technology, Bettendorf High School, Bettendorf, IA, Mississippi Bend Area Education Agency, Bettendorf, IA, Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA, Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA, Max-Planck-Institut fuer Mikrostrukturphysik, Halle, Germany, CNRS, Universite Lyon I, France, Freie Universitaet Berlin, Germany, University of Jyvaskila, Finaland, Iowa State University/Ames Laboratory, Materials Science Division, Argonne National Laboratory and Department of Chemistry, Northwestern University, Materials Science Division, Argonne National Laboratory, Advanced Photon Source, Argonne National Laboratory, Ames Laboratory and Iowa State University, Indiana University, Illinois State University, University of Iowa, Louisiana State University, University of Warwick, Rutherford Appleton Laboratory, Coe College, University of Northern Iowa, Iowa State University and Ames Laboratory, University of Illinois, Ames Laboratory, University of Florida, Tulane University, The Department of Physics and The James Franck Institute, The University of Chicago, J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS 66506, Department of Physics, Augustana College, Sioux Falls, SD 57197, Intense Laser Physics Theory Unit, Illinois State University, Argonne National Laboratory, Dr, Drake University, Physics Department, Ocean University of China, Qingdao, Physics Department, Southern Illinois University Carbondale, Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, USA, Department of Physics, The University of Texas at Austin, Austin, Texas 78712, USA, NEST-CNR-INFM and Scuola Normale Superiore, I-56126 Pisa, Italy, University of New Hampshire Department of Physics, University of Chicago