Accurate measurement of the Newtonian constant of gravity using atom interferometry

Summary form only given. We report on the accurate measurement of the Newtonian constant of gravity G, using an atom interferometry gravity-gradiometer. The probes of the gravitational field are two clouds of laser cooled
⁸⁷
Rb atoms vertically separated. Their differential vertical acceleration is measured for different positions of nearby source masses. After preliminary results obtained with lead masses, the gravitational signal is generated now by heavier, well-characterized tungsten masses. The systematic effects affecting the accuracy of the measurement have been carefully evaluated.