Drift occurs when the robot turns( scan data ).

edit

You can try bumping up the laser scanning update rate if you can, it should help a bit.

Another way of possible (but much harder) solution would be to use topic_tools transform method to rotate laser scan in advance while rotating the robot and message_filters Time Synchronizer to bind this transformation to current info from IMU/cmd_vel/any source for current non-zero angular velocity, etc.

This approach can of course work with other tools, you could save last angular velocity somewhere (updated in the angular velocity source sensor callback) and use it to transform the incoming laser data accordingly.

Of course, this will be insufficient if the computing power of the robot is low - you may have situations where you rotate the laser scan data too late and it won't help at all (and will even increase your drift more).