| According to the equivalence principle of General Relativity, point test bodies experience the same gravitational acceleration when placed in identical gravitational fields. This result is known as 'The Universality of Free Fall.' Tests of universality of free fall provide a very powerful method of searching for "ultra-feeble" macroscopic interactions that could arise from the exchange of low-mass scalar or vector bosons.; We used a torsion balance to compare the accelerations of copper and lead towards a uniformly rotating 3 ton uranium attractor, and found a(Cu){dollar}-{dollar}a(Pb) = (0.7 {dollar}pm{dollar} 5.1 {dollar}pm{dollar} 1.6) {dollar}times{dollar} 10{dollar}sp{lcub}-13{rcub}{dollar} cm/s{dollar}sp2{dollar}, which should be compared to the gravitational acceleration towards the attractor of 9.8 {dollar}times{dollar} 10{dollar}sp{lcub}-7{rcub}{dollar} cm/s{dollar}sp2{dollar}. This null result sets new constraints on possible interactions down to 1 cm, and in particular rules out earlier suggestions of a Yukawa interaction coupled essentially to N-Z.; This dissertation includes a thorough description of the apparatus and analysis procedures. Particular attention is paid to the control of systematic effects, which enabled us to set such stringent limits. |
