9,013 research outputs found
Role of T-odd functions in high energy hadronic collisions
I propose a simple model for predicting the enegy behavior of T-odd, chiral
odd function . Furthermore I illustrate a method for extracting
and the transversity function from Drell-Yan. The method may be
applied also to other reactions.Comment: Talk given at Brookhaven, Spin-200
Transverse Spin Asymmetries in Drell-Yan Processes: }
We consider two different spin asymmetries in Drell-Yan processes generated
by the collisions of an unpolarized proton beam on transversely polarized
protons: the muon helicity asymmetry and the left-right asymmetry. We calculate
the asymmetries in the framework of the QCD improved parton model, taking into
account the parton transverse momentum and considering the first order QCD
corrections. The muon helicity asymmetry is sensitive to the quark transversity
distribution and is nonvanishing even at zero order. On the contrary the
left-right asymmetry vanishes at zero order but not at first order in the QCD
coupling constant, as a result of gluon contribution
Q^2 Dependence of the azimuthal Asymmetry in Unpolarized Drell-Yan
We study the azimuthal asymmetry of the unpolarized Drell-Yan in the
framework of the T-odd functions. We find, on the basis of quite general
arguments, that for |{\bf q}_{\perp}| << Q such an asymmetry decreases as
Q^{-2}, where {\bf q}_{\perp} and Q are respectively the transverse momentum
and the center-of-mass energy of the muon pair. The experimental results
support this conclusion.Comment: 15 pages, 4 figures. Presented at "HiX2004", Marseille, July 26-28,
200
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