1. What pHe3 can teach us  Polarized He-3 is an effective neutron target  d-quark target  Polarized protons are an effective u-quark target 1 Therefore combining pp and pHe3 data will allow a full quark flavor separation u, d, ubar, dbar Two physics trusts for a polarized pHe3 program:  Measuring the sea quark helicity distributions through W-production  Access to  dbar  Caveat maximum beam energy for He-3: 166 GeV  Need increased luminosity to compensate for lower W-cross section  Measuring single spin asymmetries A N for pion production and Drell-Yan  expectations for A N (pions)  similar effect for π ± ( π 0 unchanged) 3 He: helpful input for understanding of transverse spin phenomena Critical to tag spectator protons from 3He with roman pots

2. eRHIC: polarized eHe3 scattering  Future:  Polarized electron – proton and electron – He3 scattering allows for a test of the best know Sum Rule in QCD The Bjoerken Sum Rule 2 Calculated in pQCD Currently measured to 10% EIC could provide a 1-2% measurement, if beam polarization Is measured to 1-2% g 1 p and g 1 n : polarized structure functions

3. More insights to the proton E.C. Aschenauer He-3 Workshop, BNL, September 2011 Unpolarized distribution function q(x), G(x) Helicity distribution function  q(x),  G(x) Transversity distribution function  q(x) Correlation between and Sivers distribution function Boer-Mulders distribution function beyond collinear picture Explore spin orbit correlations 3

4.  q: W Production Basics E.C. Aschenauer He-3 Workshop, BNL, September 2011 4 u u dd Since W is maximally parity violating  W’s couple only to one parton helicity large Δu and Δd result in large asymmetries. No Fragmentation ! Similar expression for W - to get Δ and Δd…

5. de Florian, Vogelsang expectations for A L e in pp collisions E.C. Aschenauer He-3 Workshop, BNL, September 2011 5 t largeu large strong sensitivity to t largeu large limited sensitivity to

6. A L W : Future Possibilities E.C. Aschenauer He-3 Workshop, BNL, September 2011 6  Can we increase p-beam energy?  325 GeV: factor 2 in  W  access to lower x for  g(x)  Increased beam-energy and polarized He-3 beam  full flavor separation A L W : pp @ 500 GeV A L W : He3-p @ 432 GeV phase 2 of pp2pp@STAR can separate scattering on n or p

7. Quantum phase-space tomography of the nucleon 3D picture in momentum space 3D picture in coordinate space transverse momentum generalized parton distributions dependent distributions  exclusive reaction like DVCS E.C. Aschenauer He-3 Workshop, BNL, September 2011 7 Polarized p d-quark u-quark Join the real 3D experience !! TMDs GPDs Wigner Distribution W(x,r,k t ) d3rd3r d 2 k t dz

8. E.C. Aschenauer He-3 Workshop, BNL, September 2011 A N in 3 He-proton collisions Sivers fcts. for u and d quarks opposite in sign and slightly larger for d quarks Z. Kang @ 2010 Iowa RSC meeting u d isospin rotation leads to different signs for A N for protons and neutrons asymmetries for neutrons are larger (due to electric charges) expectations for Drell Yan proton neutron expectations for A N (pions) similar effect for π ± ( π 0 unchanged) this time computed within twist-3 formalism here, effect due to favored/unfavored fragmentation caveat: does not yet include possibility of nodes in Sivers function 3He: helpful input for understanding of transverse spin phenomena 8 The long term future future of pp@RHIC