Eur. Phys. J. C (2008) 58: 29-35
https://doi.org/10.1140/epjc/s10052-008-0739-7

Regular Article - Theoretical Physics

Comment on the recent COMPASS data on the spin structure function g ₁

¹ Ioffe Physico-Technical Institute, 194021, St. Petersburg, Russia
² Department of Physics and INFN, University Rome III, Rome, Italy
³ St. Petersburg Institute of Nuclear Physics, 188300, Gatchina, Russia

^* e-mail: mario.greco@roma3.infn.it

Received: 10 July 2008
Revised: 31 July 2008
Published online: 26 September 2008

Abstract

We examine the recent COMPASS data on the spin structure function g ₁ singlet. We show that it is rather difficult to use the data in the present form in order to draw conclusions on the initial parton densities. However, our tentative estimate is that the data better agree with positive than with negative initial gluon densities.