A light scalar from walking solutions in gauge-string duality

We consider the type-IIB background generated by the strong-coupling limit of N(c) D5 branes wrapped on S(2), and focus our attention on a special class of solutions that exhibit walking behavior We compute numerically the spectrum of scalar fluctuations around Vacua Of this Class Besides two cuts. and sequences of single poles converging oil one of the branch points, the spectrum contains one isolated scalar, the mass of which is suppressed by the length of the walking region Approximate scale-invariance symmetry in the walking region Suggests that this might be interpreted as a light dilaton, the pseudo-Goldstone boson of dilatations (C) 2010 Elsevier B V All rights reserved