Superstring Interactions
David Balin, A. Love · 1994
Apart from the intrinsic interest in formulating a consistent, relativistic quantum string theory, its importance stems from the fact (belief) that it may provide a finite quantum theory of all of the interactions in nature, including gravitation. The particles whose interactions we study are identified with single (massless) modes of the string. If we are to ascertain the consistency (or lack of it) of string theory with the real world, it is obviously essential that we can calculate scattering amplitudes whose external lines represent single-particle states, but whose internal structure includes all of the allowed string modes, not just a few single-particle states. Thus we are interested in calculating diagrams such as the closed-string diagrams shown in figure 12.1 .