Summary of Spin Physics Parallel Sessions

We summarize the activities in the spin physics parallel sessions of the $8^{\rm th}$ conference on intersections between particle and nuclear physics.Comment: Latex, 5 pages, to appear in the Proceedings of the 8th Conference on Intersections between Particle and Nuclear Physics (CIPANP 2003

Upsilon Transverse Momentum at Hadron Colliders

We predict the shape of the transverse momentum p_T spectrum of Upsilon production. The distribution at low p_T is dominated by the region of small impact parameter b and may be computed reliably in perturbation theory. We resum to all orders in the strong coupling alpha_s the process-independent large logarithmic contributions that arise from initial-state gluon showers in the small p_T (< M_Upsilon) region. The cross section at large p_T is represented by the alpha_s^3 lowest-order non-vanishing perturbative contribution.Comment: 4 pages, 5 figures. Presented at the 2004 Meeting of the APS Division of Particles and Fields, University of California, Riverside, CA, Aug 26-31, 200

Breakdown of Conventional Factorization for Isolated Photon Cross Sections

Using $e^+e^-\rightarrow\gamma + X$ as an example, we show that the conventional factorization theorem in perturbative quantum chromodynamics breaks down for isolated photon cross sections in a well defined part of phase space. Implications and physical consequences are discussed.Comment: 11 pages, RevTex, 1 figure in postscrip

QCD and Rescattering in Nuclear Targets

We review the extension of the factorization formalism of perturbative QCD to soft rescattering associated with hard processes in nuclei.Comment: Latex 16 pages, including 18 figures, to appear in the Proceedings of Hard Probe Collaboratio