A New Mechanism for Generating a Single Transverse Spin Asymmetry

作者：Sievert Matthew D^*

来源：Nuclear Physics A, 2013, 904: 833C-836C.

DOI：10.1016/j.nuclphysa.2013.02.145

Here we briefly outline the calculation of the single transverse spin asymmetry due to a new perturbative, saturation-mediated mechanism in high energy QCD. We use light-cone perturbation theory to study a simple model in which a transversely polarized quark scatters on a proton or nuclear target. The spin dependence of the scattering cross section is introduced by the lowest-order q -> qG splitting wave function of the polarized projectile, while the time-reversal odd property of the asymmetry is generated by the antisymmetric odderon dipole scattering amplitude. We study the properties of the obtained STSA, some of which are in qualitative agreement with experiment: STSA increases with increasing projectile x(F) and is a non-monotonic function of the transverse momentum k(T). Our mechanism predicts that the quark STSA in polarized proton-nucleus collisions should be much smaller than in polarized proton-proton collisions. We also observe that the STSA for prompt photons due to our mechanism is zero within the accuracy of the approximation.

• 出版日期2013-5-2