Publication at Faculty of Mathematics and Physics |
2016
Abstract
The Sivers asymmetry in J/psi production in scattering of muons off transversely polarized protons mu(+)+p up arrow -> mu(+) + J/psi+ X is measured in two z-bins (inclusive and exclusive production) in the COMPASS 2010 data. Only J/psi's decaying into muons are detected.
About 2 230 and 4 450 J/psi events in the lower and the higher z-bins are found. The Sivers asymmetry is extracted using a simple double-ratio method and is found to be compatible with zero in the lower z bin and to have a slight preference for negative values in the higher z bin.