Speaker
Oleg Eyser
(B)
Description
Understanding the spin structure of the proton is deeply entangled with the properties and dynamics of quarks and gluons as descibed by the theory of quantum chromodynamics (QCD). Transversity is one of three leading twist parton distribution functions in collinear perturbative QCD and so far the least well known due to its chiral odd nature. Experimentally, it can only be observed in combination with additional spin dependent final state effects. These can include interference fragmentation functions in the collinear picture or the so-called Collins fragmentation in a transverse momentum dependent (TMD) framework. Similarly, initial state TMD distribution functions (Sivers effect) can cause transverse asymmetries. The PHENIX experiment at RHIC has measured transverse observables of various probes in polarized proton-proton collisions in the past. New data at $\sqrt{s}=200$ GeV has been recorded in 2012 with an integrated luminosity of 9.2 pb$^{-1}$ and average beam polarizations of $\approx 58\%$ (more than twice the figure of merit of previously accumulated data). In this talk we will present recent results and discuss the status of on-going efforts and their possible implications for a global analysis.
Author
Oleg Eyser
(B)
