Single Transverse - Spin Asymmetry in pp ↑ → πX and ep ↑ → πX

Predictions for single spin asymmetries in ℓp ↑ → πX and γ ∗ p ↑ → πX

Predictions for the single transverse spin asymmetry AN in semi-inclusive DIS processes are given; non negligible values of AN may arise from spin effects in the fragmentation of a polarized quark into a final hadron with a transverse momentum k⊥ with respect to the jet axis, the so-called Collins effect. The elementary single spin asymmetry of the fragmenting quark has been fixed in a previous...

40 0 v 1 2 6 N ov 2 00 2 1 Single Transverse Spin Asymmetry in p ↑ p → πX and ep ↑ → πX

N ov 2 00 2 Single Transverse - Spin Asymmetry in pp ↑ → πX and ep ↑ → πX

where the functions Ga(x1, x2), Eb(x ′ 1, x ′ 2) and Êc(z1, z2) are the twist-3 quantities representing, respectively, the transversely polarized distribution, the unpolarized distribution, and the fragmentation function for the pion. δqa(x) is the transversity distribution in p↑. a, b and c stand for the parton’s species, sum over which is implied. δqa, Eb and Êc are chiral-odd. Corresponding ...

ar X iv : h ep - p h / 99 05 49 0 v 1 2 6 M ay 1 99 9 1 Single transverse spin asymmetries in inclusive hadron production

A consistent phenomenological approach to the computation of transverse single spin asymmetries in inclusive hadron production is presented, based on the assumed generalization of the QCD factorization theorem to the case in which quark intrinsic motion is taken into account. New k⊥ and spin dependent quark distribution and fragmentation functions are considered: some of them are fixed by fitti...

Phenomenology of single spin asymmetries in p ↑ p → πX

A general formalism, based on factorization theorem and pQCD hard interactions, is developed for the description of single spin effects in hadron-hadron inclusive processes. The transverse momentum, k⊥, of the quarks inside the hadrons and of the hadrons relatively to the fragmenting quark, is taken into account in distribution and fragmentation functions, and leads to possible non zero single ...