MG12 - Talk detail |
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Participant |
Bonicalzi, Ricco | |
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Institution |
University of Washington - Physics Department, Box 351560 - Seattle - WA - USA | |
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Session |
Talk |
Abstract |
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EG5-EG7 |
A New Experimental Test of the Inverse-Square Law |
We report early results from an oscillating torsion pendulum experiment that has set an improved upper bound on the strength of gravitational inverse square law violation (ISLV) for interaction between macroscopic bodies with a separation of order 10 cm. An important design feature is the special mass configurations of both the pendulum and gravitational source. These provide high sensitivity to the horizontal derivative of the Laplacian of the gravitational potential, a unique signature of ISLV, while strongly suppressing couplings through Newtonian gravity that can mimic this signature. A key aspect of this work is the use of the second-harmonic amplitude of the pendulum's motion as the interaction observable instead of the traditional oscillation frequency. This newer technique is markedly less sensitive to changes in temperature and tilt of the instrument. |