The lift differential that exists between the advancing main rotor blade and the retreating main rotor blade is known as

Explanation

In forward flight the advancing blade meets a higher relative wind than the retreating blade, and the resulting difference in lift across the rotor disk is called dissymmetry of lift (Helicopter Flying Handbook). Transverse flow effect is a lift difference between the front and rear of the disk, and hunting is a blade's lead-lag movement.