  One of the plausible unification schemes in physics considers the observable
universe to be a 4-dimensional surface (the "brane") embedded in a
higher-dimensional curved spacetime (the "bulk"). In such braneworld gravity
models with infinitely large extra dimensions, black holes evaporate fast
through the emission of the additional gravitational degrees of freedom,
resulting in lifetimes of stellar-mass black holes that are significantly
smaller than the Hubble time. We show that the predicted evaporation rate leads
to a change in the orbital period of X-ray binaries harboring black holes that
is observable with current instruments. We obtain an upper limit on the rate of
change of the orbital period of the binary A0620-00 and use it to constrain the
asymptotic curvature radius of the extra dimension to a value comparable to the
one obtained by table-top experiments. Furthermore we argue that any
measurement of a period increase for low-mass X-ray binaries with a high mass
ratio is evidence for new physics beyond general relativity and the standard
model.
