NEW TESTS OF THE UNIVERSALITY OF FREE-FALL

We use a continuously rotating torsion balance to make new tests of th e universality of free fall (UFF). We study differential accelerations of Be-Cu and Be-Al test-body pairs in the fields of Earth, the Sun, o ur Galaxy, and in the direction of the cosmic microwave dipole. We als o compare the acceleration towards the Sun and our galactic center of Cu and single-crystal Si in an Al shell (this pair of bodies approxima tes the elemental compositions of Earth's core and the Moon or Earth's crust, respectively). In terms of the classic UFF parameter eta, our Earth-source results are eta(Be,Cu) = (-1.9 +/- 2.5) x 10(-12) and eta (Be,Al) = (-0.2 +/- 2.8) x 10(-12) where all errors are 1 sigma. Thus our limit on UFF violation for Be and a composite Al/Cu body is eta = (-1.1 +/- 1.9) x 10(-12). Our solar-source results are Delta a(Be,Cu) = (-3.0 +/- 3.6) x 10(-12) cm/s(2), Delta a(Be,Al) = (+ 2.4 +/- 5.8) x 10(-12) cm/s(2), and Delta a(Si/Al,Cu) = (+ 3.0 +/- 4.0) x 10(-12) c m/s(2). This latter result, when added to the lunar laser-ranging resu lt that senses both composition-dependent forces and gravitational bin ding-energy anomalies, yields a nearly model-independent test of the U FF for gravitational binding energy at the 1% level. A fivefold tighte r limit follows if composition-dependent interactions are restricted t o vector forces. Our galactic-source results test the UFF for ordinary matter attracted toward dark matter, yielding eta(DM)(Be,Cu) = (-1.3 +/- 0.9) x 10(-3), eta(DM)(Be,Al) = (+ 1.8 +/- 1.4) x 10(-3) and eta(D M)(Si/Al,Cu) = (+ 0.7 +/- 1.0) x 10(-3). This provides laboratory conf irmation of the usual assumption that gravity is the dominant long-ran ge interaction between dark and luminous matter. We also test Weber's claim that solar neutrinos scatter coherently from single crystals wit h cross sections similar to 10(23) times larger than the generally acc epted value and rule out the existence of such cross sections.