E-8 FLAVOR MULTIPLETS - ART. NO. 106005

We analyze gauge symmetry enhancements S0(16)-->E-8 on eight D7-branes and SO(14) x U(1)-->E-8 on seven D7-branes from open strings. String configurations that we present in this paper are closely related to th e ones given by Gaberdiel and Zwiebach. Our construction is based on S O(8) X SO(8) decomposition, and its relation to the D8-brane case via T duality is clearer. Then we study supersymmetric Yang-Mills theory o n D3-brane near the D7-branes. This theory has a flavor symmetry group that is equal to the gauge group on D7-branes. We suggest that when t his symmetry is enhanced, two dyons make bound states that, together w ith elementary quarks, constitute an E-8 multiplet. [S0556-2821(98)071 20-3].