  In this work we seek evidence for global torsional oscillations in alpha
sunspots. We have used long time series of continuum intensity and magnetic
field vector maps from the Helioseismic and Magnetic Imager (HMI) instrument on
board the Solar Dynamics Observatory (SDO) spacecraft. The time series analysed
here span the total disk passage of 25 isolated sunspots. We found no evidence
of global long-term periodic oscillations in the azimuthal angle of the sunspot
magnetic field within $\sim$ 1 degree. This study could help us to understand
the sunspot dynamics and its internal structure.
