https://doi.org/10.1140/epjc/s10052-013-2291-3
Regular Article - Theoretical Physics
The cos2ϕ azimuthal asymmetry of unpolarized dilepton production in 
collisions around Z-resonance
1
School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, 100871, China
2
Center for High Energy Physics, Peking University, Beijing, 100871, China
* e-mail: mabq@pku.edu.cn
Received:
17
September
2012
Revised:
7
December
2012
Published online:
29
January
2013
We calculate the cos2ϕ azimuthal asymmetry of the unpolarized dilepton production process in the Z-resonance region at the Tevatron kinematic domain. Compared to the pp process, such an azimuthal asymmetry can provide additional information about a spin-related three-dimensional parton distribution function of the proton, the Boer–Mulders function. It plays a significant role in separating the contributions of the valence quarks and of the sea quarks. Besides, the Z production process is much different from the virtual photon mediate Drell–Yan process as well as the J/ψ and ϒ production processes. Our estimation indicates that this asymmetry is sizable to be detected. Therefore the available data of unpolarized proton–antiproton collision at Tevatron can contribute to our study on the spin-related structure of the nucleon.
© Springer-Verlag Berlin Heidelberg and Società Italiana di Fisica, 2013
