Workshop on Quark-gluon Thermalization Vienna, August 10-12, 2005 In collaboration with Zuo-tang Liang Xin-Nian Wang/LBNL Thermalization and Globally Polarized QGP in Non-central Heavy-ion Collisions Instability and Cerenkov Radiation Phys. Rev. Lett. 94 (2005)102301

Direct Signs for Thermalization from away jets from medium decay Leading hadrons Medium Fuqiang Wang

Global Orbital Angular Momentum x z y Low-energy nuclear collisions: Stiff EOS P~  E Rotation and deformed nuclei x z y

p A  Global Orbital Angular Momentum x z y x z y High-energy Nuclear Collisions

Nuclei Are Spherical ! 3D distribution of multiplicity and Momentum Heinz & Kolb’04 Adil & Gyulassy’5

Transverse Gradient of Shear Velocity Distribution of number of participant projectile or target nucleons Collective longitudinal momentum per produced parton x z b

Local Orbital Angular Momentum (x-b/2)/R A xx

Quark Scattering with fixed L y Screened static potential model: xTxT p n pfpf

Quark Polarization Unpolarized cross section: Polarized cross section: Semi-central: b=R A xTxT p n pfpf

A New Picture of A+A Spin-orbital coupling xTxT p n pfpf

Consequences  Single-spin asymmetry: Polarized thermal dilepton, J/  Hyperons and vector mesons Directed flow? Enhanced  / ,  /p ratio

Constituent Quark Recombination Polarization of valence quarks + relative orbital angular momentum Polarization of constituent quarks Constituent quark model: (l=0, color anti-symmetric)

Features of Global Hyperon Polarization Hyperons & anti-hyperons are similarly polarized P H =0 in central and increases with b P q  0 for p T >>  p 0z, P H finite for moderate p T due to hard-soft recombination Contribution from directed flow at large y

Other effects P  >0 P  <0 Hadronic scattering:   

Thoughts for the Brave… N1N1 N2N2 N2> N1 v 2 in p+A collisions?

Summary Shear velocity gradient leads to global polarization if there is interaction across transverse direction due to thermalization A new picture of QGP structure in heavy- ion collisions: –Hyperon polarization, vector meson spin alignment, contribution to v2 Future work: –Quantitative evaluation of hadronic interaction –Spin transport: spintronics of strong interaction