Gravitational origin of quark masses in an extra-dimensional brane world

Using the warped extra dimension geometry of the many-brane extension of th e Randall-Sundrum solution, we find a natural explanation for the observed quark masses of the three Standard Model (SM) generations. Localizing massl ess SM matter generations on neighboring 3-branes in an extra-dimensional w orld leads to phenomenologically acceptable effective four-dimensional mass es arising from the coupling of the fermion field with the background metri c. Thus this geometry can simultaneously address the gauge and quark mass h ierarchy problems. (C) 2001 Published by Elsevier Science B.V.