Double-transverse spin asymmetries at NLO

We report on a next-to-leading order QCD calculation of the cross section and the spin asymmetry for isolated large-p_T prompt photon production in collisions of transversely polarized protons. Corresponding measurements may be used at RHIC to determine the transversity parton distributions of the proton.Comment: 3 pages, LaTeX, 1 figure as eps file. Invited talk presented by W. Vogelsang at the "Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2003)", New York City, May 19-24, 200

The resummed Higgs boson transverse momentum distribution at the LHC

We apply QCD resummation techniques to study the transverse momentum distribution of Higgs bosons produced via gluon-gluon fusion at the LHC. In particular we focus on the joint resummation formalism which resums both threshold and transverse momentum corrections simultaneously. A comparison of results obtained in the joint and the standard recoil resummation frameworks is presented.Comment: 9 pages, 1 figure, uses appolb.cls. Contribution to the Proceedings of XXVII International Conference of Theoretical Physics, Ustron, Poland, September 15-21, 2003. To appear in Acta Physica Polonica

Electroweak vector boson production in joint resummation

We study the application of the joint resummation to electroweak boson production at hadron colliders. The joint resummation formalism resums both threshold and transverse momentum corrections to the transverse momentum distribution at next-to-leading logarithmic accuracy. We obtain a good description of the transverse momentum distribution of Z bosons produced at the Tevatron collider.Comment: 5 pages, 2 figures. Talk presented by A. Kulesza at the XXXVIIth Rencontres de Moriond `QCD and high energy hadronic interactions', Les Arcs, Franc

Next-to-leading Order QCD Corrections to A_TT for Single-Inclusive Hadron Production

We report on a calculation of the next-to-leading order QCD corrections to the partonic cross sections contributing to single-inclusive high-p_T hadron production in collisions of transversely polarized hadrons. We give some predictions for the double spin asymmetry A_TT^\pi for the proposed experiments at RHIC and at the GSI.Comment: Presented at DIS 2005, Madison, Wisconsin, USA, April 27-May 1, 200

Twist Three Distribution f_\perp(x,k^\perp) in Light-front Hamiltonian Approach

We calculate the twist three distribution f_\perp(x,k^\perp) contributing to Cahn effect in unpolarized semi-inclusive deep inelastic scattering. We use light-front Hamiltonian technique and take the state to be a dressed quark at one loop in perturbation theory. The 'genuine twist three' contribution comes from the quark-gluon interaction part in the operator and is explicitly calculated. f_\perp(x,k^\perp) is compared with f_1(x,k^\perp).Comment: Two figures added, one author added, some parts rewritten for clarificatio

Crossed Threshold Resummation

We show that certain general properties of threshold and joint resummations in Drell-Yan cross sections hold as well for their crossed analogs in semi-inclusive deep-inelastic scattering and double-inclusive leptonic annihilation. We show that all plus-distribution corrections near threshold show the same structure, and are determined to all logarithmic order by two anomalous dimensions, one of which is a generalization of the D-term previously derived in Drell-Yan. We also discuss the possibility of universality in power corrections implied by the resummation.Comment: 8 page

Hadronic Dijet Imbalance and Transverse-Momentum Dependent Parton Distributions

We compare several recent theoretical studies of the single transverse spin asymmetry in dijet-correlations at hadron colliders. We show that the results of these studies are all consistent. To establish this, we investigate in particular the two-gluon exchange contributions to the relevant initial and final state interactions in the context of a simplifying model. Overall, the results confirm that the dijet imbalance obeys at best a non-standard or "generalized" transverse-momentum-dependent factorization.Comment: 13 pages, 3 figure

Next-to-leading order QCD corrections to single-inclusive hadron production in transversely polarized p-p and pbar-p collisions

We present a calculation of the next-to-leading order QCD corrections to the partonic cross sections contributing to single-inclusive high-p_T hadron production in collisions of transversely polarized hadrons. We use a recently developed projection technique for treating the phase space integrals in the presence of the cos(2Phi) azimuthal-angular dependence associated with transverse polarization. Our phenomenological results show that the double-spin asymmetry A_TT^pi for neutral-pion production is expected to be very small for polarized pp scattering at RHIC and could be much larger for the proposed experiments with an asymmetric pbar-p collider at the GSIComment: 7 pages, 5 figure