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Impact of CLAS and COMPASS data on Polarized Parton Densities and Higher Twist

Elliot Leader·Aleksander V. Sidorov·Dimiter B. Stamenov
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Abstract

We have re-analyzed the world data on inclusive polarized DIS including the very precise CLAS proton and deuteron data, as well as the latest COMPASS data on the asymmetry $A_1^d$, and have studied the impact of these data on polarized parton densities and higher twist effects. We demonstrate that the low $Q^2$ CLAS data improve essentially our knowledge of higher twist corrections to the spin structure function $g_1$, while the large $Q^2$ COMPASS data influence mainly the strange quark density. In our new analysis we find that a negative polarized gluon density, or one that changes sign as a function of x, cannot be ruled out from the present DIS data.

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Elliot Leader, Aleksander V. Sidorov, Dimiter B. Stamenov. 2007-04-10. Impact of CLAS and COMPASS data on Polarized Parton Densities and Higher Twist. https://doi.org/10.1103/physrevd.75.074027

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