Transverse Spin Physics at RHIC II M. Grosse Perdekamp University of Illinois and RIKEN BNL Research Center Strong Interaction Physics at BNL RHIC  RHIC II  e-RHIC RHIC II Luminosity and Detector Upgrades Overview of the Physics Program Transverse Spin Physics Collins and Interference Fragmentation Drell Yan pp2pp STAR QCD N06 , June 12 - 16, 2006, Rome, Italy

Strong Interaction Physics at e-RHIC RHIC II RHIC Quark Matter at high Temperatures and Densities ion-ion collisions (Cu-Cu, Au-Au: √sNN=22.5, 62, 130, 200 GeV) Proton Spin Structure polarized proton-proton collisions (p-p: √s=200 to 500 GeV) Low-x and high parton densities ion-deuteron collisions (d-Au: √sNN=200 GeV) high luminosity, detector upgrades high luminosity, dedicated transverse spin experiment? polarized e-p very active field:  74 PRL letters in the first 5 years RHIC II high luminosity, detector upgrades polarized e-p June 16th Transverse Spin Physics at RHIC II

Transverse spin program at RHIC is luminosity limited Physics channel Luminosity? RHIC by 2009 at 200 GeV ∫Ldt ~275pb-1 delivered ∫Ldt ~100pb-1 accepted (eg. PHENIX: vertex cut, trigger efficiencies, duty factor)  ∫Ldt ~25 pb-1 transverse AN yes, very good AN(back-to-back) good AT (Collins FF) fair AT (Interference FF) limited ATT (Jets) not studied experimentally AT (Drell Yan) --- ATT( Drell Yan) --- Direct photons, Ws --- (AN,AT(CFF, IFF)) RHIC II Dedicated Drell Yan experiment for transverse spin physics at RHIC ? June 16th Transverse Spin Physics at RHIC II

Transverse Spin Physics at RHIC II RHIC II – Definition Electron Cooling in RHIC to increase luminosity for HI by factor 10 Detector Upgrades in PHENIX and STAR Drell Yan Experiment for Transverse Spin? target date 2012 RHIC II upgrades will be carefully coordinated with the effort to build a electron ion collider  RHIC as “QCD Lab” June 16th Transverse Spin Physics at RHIC II

Transverse Spin Physics at RHIC II RHIC II: Luminosity Upgrade with Electron Cooling (from Thomas Roser) June 16th Transverse Spin Physics at RHIC II

p-p Expectations for the RHIC II Luminosity Upgrade Factor 2-3 increase in pp luminosity Small improvements in polarization Maximum energy √s = 650 GeV Operation at 20-30% higher energy possible Can have polarized 3He2+ beams Mini-quads at one IP can boost luminosity by a factor 3-5  assume factor 10 possible with mini-quads, if mini- quads can be integrated with detector design! June 16th Transverse Spin Physics at RHIC II

RHIC  five complementary experiments RHIC II: Room for New Ideas! RHIC  five complementary experiments 100% transverse ! pp2pp June 16th Transverse Spin Physics at RHIC II

RHIC II: Transverse Spin Physics High Rate (N) Experiment RHIC II: Upgrades in STAR and PHENIX T-SPHINX HBD (Hadron Blind Detector) Silicon (VTX, FVTX) Muon Trigger Forward Calorimeter FMS (Forward Meson Spectrometer) TOF HFT (Heavy Flavor Tracker) Tracking Upgrade DAQ June 16th Transverse Spin Physics at RHIC II

RHIC II: Transverse Spin Physics High Rate (N) Experiment T-SPHINX Large acceptance Drell Yan experiment: (1) 100 % Transverse Spin x 4 (2) Large acceptance -3<η<+3 x 8 (3) Electron cooling x 2.5 (4) Mini-quads x 4 ~300 Physics: Sivers-, Transversity-, Boer-Mulder-distributions in Drell Yan lepton pair production at RHIC. Relative gain in ∫Ldt Compared to PHENIX June 16th Transverse Spin Physics at RHIC II

Transverse Spin Physics at RHIC II RHIC II Schedule: Detector Upgrades + Luminosity High statistics Au-Au, 500 GeV pp RHIC II Luminosity upgrade June 16th Transverse Spin Physics at RHIC II

Science at RHIC II report: Summer 2006 RHIC II Science Workshops: Spin Physics BNL, October 7-8, 2005 Transverse spin physics: S. Menzel (Bochum), L. Gamberg (Penn State), J. Soffer (Marseille), M. Burkardt (New Mexico), F. Yuan (RBRC), M. Radici (Pavia) Hyperons : Z. Liang (Shandong), Q. Xu (Shandong+LBL), K. Sudoh (KEK) W-physics: P. Nadolsky (Argonne), K. Sudoh (KEK), J. Soffer (Marseille) Beyond the SM: J. Soffer (Marseille), D. Maitre (Zurich) Science at RHIC II report: Summer 2006 June 16th Transverse Spin Physics at RHIC II

Physics Channels for RHIC II (RHIC II Spin Working Group, E. Sichterman, M. Stratmann, MGP, et al.) Precision measurement of the proton helicity structure o ∆G(x) and ∆q(x), ∆q(x) with high luminosity in multiple channels with available detector upgrades. Extend measurements to 3He  neutron. (can this be done with high polarization + intensity??)  minimize errors and increase x-coverage of ∆G(x) for precision measurement of the first moment of the spin-dependent gluon distribution ∆G=ʃ ∆G(x)dx.  observe scale evolution of the first moment.  global QCD analysis for best knowledge of polarized nucleon structure + pdfs Precision cross section measurements + QCD analysis o Measure cross sections in direct photon production, inclusive jet + hadron production as input to QCD analysis to improve knowledge of  G(x) at large x  Gluon fragmentation function June 16th Transverse Spin Physics at RHIC II

Transverse Spin Physics at RHIC II Physics Channels for RHIC II Polarization of the strange sea o Access ∆s(x) through inclusive anti-Lambda production and charm associated W-production (very luminosity hungry!)  study polarization of the strange sea  verify ∆s from DIS Transverse Spin Physics o Extract transversity quark distributions from precision measurements of asymmetries in Collins- and interference fragmentation. o Measure transversity-, Sivers- and Boer-Mulders asymmetries in Drell Yan. AN in direct photon and W production. June 16th Transverse Spin Physics at RHIC II

QCD analysis of Belle IFF and RHIC AT in IFF to extract transversity Transversity from Interference Fragmentation (Efremov, Collins, Heppelman, Ladinsky, Atru, Jaffe, Jin, Tan, Radici, Jacob, Bacchetta) QCD analysis of Belle IFF and RHIC AT in IFF to extract transversity June 16th Transverse Spin Physics at RHIC II

Integrated Luminosity for RHIC II ~ 125 pb-1 Projected statistical errors in one invariant mass bin 800 MeV < m < 950 MeV 1% 2% IFF from Belle AT from STAR+PHENIX June 16th Transverse Spin Physics at RHIC II

Drell Yan Physics with T-SPHINX Transversity : correlation between transverse proton spin and quark spin Sivers : correlation between transverse proton spin and quark transverse momentum Boer/Mulders: correlation between transverse quark spin and quark transverse momentum June 16th Transverse Spin Physics at RHIC II

Transverse Spin Physics at RHIC II Sivers-Asymmetries, AT in Drell Yan (J. Collins et al.) Sensitivity to anti-quark Sivers distribution (not probed at GSI) Sensitivity to sign with respect to DIS! June 16th Transverse Spin Physics at RHIC II

Precision measurement of Sivers distributions! Sivers-Asymmetries, AT in Drell Yan (J. Collins et al.) Q=4GeV Q=4GeV Q=20GeV Q=20GeV AT AT STAR for 125pb-1 T-SPHINX 1250 pb-1 o 10 o’clock  100% transverse polarization o mini-quads o acceptance: -3 < η < 3  x 300 in ∫Ldt Precision measurement of Sivers distributions! June 16th Transverse Spin Physics at RHIC II

Projections for pp at 200 GeV and 1250 pb-1 ATT for Drell Yan with dedicated DY detector projections for 1250pb-1 of running, 5-10% higher polarization, with RHIC II luminosities and large acceptance Drell Yan 1.25fb-1, large acceptance detector for Drell Yan This measurement appears to be also possible at 500 GeV June 16th Transverse Spin Physics at RHIC II

Transverse Spin Physics at RHIC II RHIC II Summary Precision measurements of asymmetries in Collins- and Interference-Fragmentation to map out quark transversity distributions. o Drell Yan AT (a) STAR can test expected sign change for the Sivers function at low invariant mass. (b) Dedicated DY experiment possible to extract Sivers quark distribution. Sensitive to anti- quark distributions! ATT Clean measurement of anti-quark and possibly quark transversity distributions o Access to Ws and direct photons. June 16th Transverse Spin Physics at RHIC II