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Transverse single spin asymmetries at mid-rapidity at √s=200 GeV in p+p collisions

Transverse single spin asymmetries at mid-rapidity at √s=200 GeV in p+p collisions. K. Oleg Eyser University of California, Riverside for the PHENIX collaboration. PANIC 2005, Santa Fe. Section III.7. Transversity. spin structure of the nucleon: Δ q, Δ g, Δ L, δ q. (Collins effect)

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Transverse single spin asymmetries at mid-rapidity at √s=200 GeV in p+p collisions

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  1. Transverse single spin asymmetriesat mid-rapidity at √s=200 GeVin p+p collisions K. Oleg Eyser University of California, Riverside for the PHENIX collaboration PANIC 2005, Santa Fe Section III.7

  2. Transversity • spin structure of the nucleon: Δq, Δg, ΔL, δq (Collins effect) spin-dependent fragmentation functions (Sivers effect) transversely asymmetric kt quark distributions (Twist-3) quark gluon field interference SSAsingle spin asymmetries E704, BELLE, BRAHMS, COMPASS, STAR, PHENIX K. Oleg Eyser

  3. CNI Pol BRAHMS RHIC PHENIX STAR OPPIS Linac AGS RHIC @ BNL K. Oleg Eyser

  4. Charged Hadrons in PHENIX drift chambercentral magnet event quality: vertex cuttrack qualityDC zed position background: RICH nPMTPC3 matching K. Oleg Eyser

  5. published: hep-ex/0507073 ≈ same statistics use for single polarized collisions Data Set • 2005 transverse polarization: • estimate ATT for systematic uncertainties in ALL • ≈70 hours from June 16 to 18, 2005 • 2001 / 2002 run: • eight weeks of transverse polarization • integral luminosity 0.15 pb-1 • hadronic cross section and analyzing power K. Oleg Eyser

  6. Hadronic Cross Section dominant systematic uncertainty:(pt < 5 GeV/c) weak decay correction(pt > 5 GeV/c) background subtraction luminosity determination:9.6% normalization uncertainty CTEQ6M NLO pCQD calculationKniehl-Kramer-Pötter FFs: consistent above 2 GeV/c extract spin-dependent PDFs K. Oleg Eyser

  7. Single Spin Asymmetries efficiencyleft / right luminosityP / P acceptancept / charge / left / right Polarizationblue / yellow K. Oleg Eyser

  8. Raw Asymmetries ε=ANP  square root formula for equal acceptance functions cross checksimple asymmetries: left / right raw vs.efficiency-corrected  / raw vs.luminosity-corrected compare and average:two beams systematic uncertainties:randomize polarization pattern of bunches polarization:CNI pC / Jet polarimeters  scaling in AN K. Oleg Eyser

  9. Analyzing Power AN hep-ex/0507073 (hep-ex/0507073) π0 (2001/02) pt (GeV/c) pt (GeV/c) P=15% in 2001/02, P=47% in 2005 polarization scaling uncertainty: 30% in 2001/02, ≈20% in 2005 residual polarization in unpolarized beam: <10% and small AN K. Oleg Eyser

  10. Summary Charged hadrons: SSA from 2001/02 and 2005increased polarization and luminosity cross section ↔ NLO pQCD calculations AN results still consistent with zerowork on neutral pions from 2005 upcoming extended transverse/radial run K. Oleg Eyser

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