We present studies of multiplicities and the $\cos\phi$, and $\cos2\phi$ moments, in charged pion production in semi-inclusive deep inelastic scattering (SIDIS).
The data set used was the E1-f run from the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab which ran in 2003.
The run used a 5.498 GeV longitudinally polarized electron beam and an unpolarized liquid hydrogen target.
Two pion channels ($\pi^+$ and $\pi^-$) were studied over a broad kinematical range ($x = 0.1 - 0.6$, $Q^2 = 1.0 - 4.5$ GeV$^2$, $z = 0.0 - 1.0$, $\Phperp^2 = 0.0 - 1.0$ GeV$^2$, and $-180^\circ < \phi_h < 180^\circ$).
These measurements give insights into the transverse momentum dependence of parton distribution functions (PDFs) describing the dynamics of quarks and gluons inside of the proton.