We present first results for lattice simulations, on a single volume, of the
low-lying spectrum of an SU(3) Yang-Mills gauge theory with ten light fermions
in the fundamental representation. Fits to the fermion mass dependence of
various observables are found to be globally consistent with the hypothesis
that this theory is within or just outside the strongly-coupled edge of the
conformal window, with mass anomalous dimension consistent with 1 over the
range of scales simulated. We stress that we cannot rule out the possibility of
spontaneous chiral-symmetry breaking at scales well below our infrared cutoff.
We discuss important systematic effects, including finite-volume corrections,
and consider directions for future improvement.Comment: 7 pages, 3 figures. Submitted to Physical Review Letters. v2:
corrected global fits. v3: corrected estimation of confidence interval
