Transverse double-spin asymmetries for small QTQ_T Drell-Yan pair production in pppp and ppˉp\bar{p} collisions

We discuss transverse double-spin asymmetries for dimuon production at small transverse-momentum $Q_T$ in $pp$ and $p\bar{p}$ collisions. All order resummation of large logarithms relevant in small $Q_T$ region is performed at next-to-leading logarithmic (NLL) accuracy, and asymmetries at RHIC, J-PARC and GSI are calculated.Comment: 4 pages, 2 figures, Talk given at DIS06, April 20-24, 2006, Tsukuba, Japa

Azimuthal angular dependence of decay lepton in e+ e- --> t tbar

We discuss top quark production and its subsequent decay for searching new physics at lepton colliders. The angular dependence of the decay leptons is calculated including both QCD corrections and anomalous gamma Z - t tbar couplings. The off-diagonal spin basis for the top and anti-top quarks is shown to be useful to probe the anomalous couplings.Comment: 12 pages, LaTeX, 9 ps figure

Unravelling soft components in the shape function for inclusive B decays

In the heavy-quark limit, the decay spectrum for radiative and semileptonic inclusive B-meson decays is determined by a universal structure function, i.e. the shape function. We study the constraints on the bilocal heavy-quark operator for the shape function from the QCD equations of motion and heavy-quark symmetry, and we obtain a new basis of nonlocal operators that reveals relevant soft components in the shape function. Those nonlocal operators represent the ``kinetic energy distribution'' of the b-quark inside the B-meson and the four-parton correlations with additional quarks and gluons. A corresponding local operator basis relevant for relating the shape function to HQET parameters is also given, and novel effects of the quark-gluon correlations are discussed.Comment: 19 pages PTPTeX. Typos corrected and improvements made to the text. References added. Published versio