https://doi.org/10.1140/epjc/s10052-017-5406-4
Regular Article - Theoretical Physics
production in polarized and unpolarized ep collision and Sivers and 
asymmetries
Department of Physics, Indian Institute of Technology Bombay, Mumbai, 400076, India
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Received:
7
July
2017
Accepted:
22
November
2017
Published online:
11
December
2017
Abstract
We calculate the Sivers and azimuthal asymmetries in production in the polarized and unpolarized semi-inclusive ep collision, respectively, using the formalism based on the transverse momentum-dependent parton distributions (TMDs). The non-relativistic QCD-based color octet model is employed in calculating the production rate. The Sivers asymmetry in this process directly probes the gluon Sivers function. The estimated Sivers asymmetry at 
is negative, which is in good agreement with the COMPASS data. The effect of TMD evolution on the Sivers asymmetry is also investigated. The asymmetry is sizable and probes the linearly polarized gluon distribution in an unpolarized proton.
© The Author(s), 2017
