p-p ' system with B field, branes at angles and noncommutative geometry

We study the generic p-p' system in the presence of constant NS 2-form B-ij field. We derive properties concerning with the noncommutativity of D-bran e worldvolume, the Green functions and the spectrum of this system. In the zero slope limit, a large number of Light states appear as the lowest excit ations in appropriate cases. We are able to relate the energies of the lowe st states after the GSO projection with the configurations of branes at ang les. Through analytic continuation, the system is compared with the branes with relative motion. (C) 2000 Elsevier Science B.V. All rights reserved.