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We present Submillimeter Array (SMA) polarization observations of the CO $J$= 3--2 line toward the NGC1333 IRAS 4A. The CO Stokes $I$ maps at an angularresolution of $\sim$1$\arcsec$ reveal two bipolar outflows from the binarysources of the NGC 1333 IRAS 4A. The kinematic features of the CO emission canbe modeled by wind-driven outflows at $\sim$ 20$\arcdeg$ inclined from theplane of the sky. Close to the protostars the CO polarization, at an angularresolution of $\sim$$2\farcs3$, has a position angle approximately parallel tothe magnetic field direction inferred from the dust polarizations. The COpolarization direction appears to vary smoothly from an hourglass field aroundthe core to an arc-like morphology wrapping around the outflow, suggesting ahelical structure of magnetic fields that inherits the poloidal fields at thelaunching point and consists of toroidal fields at a farther distance ofoutflow. The helical magnetic field is consistent with the theoreticalexpectations for launching and collimating outflows from a magnetized rotatingdisk. Considering that the CO polarized emission is mainly contributed from thelow-velocity and low-resolution data, the helical magnetic field is likely aproduct of the wind-envelope interaction in the wind-driven outflows. The COdata reveal a PA of $\sim$ 30$\arcdeg$ deflection in the outflows. Thevariation in the CO polarization angle seems to correlate with the deflections.We speculate that the helical magnetic field contributes to $\sim$ 10$\arcdeg$deflection of the outflows by means of Lorenz force.

Helical Magnetic Fields in the NGC1333 IRAS 4A Protostellar Outflows