Interacting-String Picture of the Neveu-Schwarz-Ramond Model

Abstract

The interacting-string picture i~ extended to the NeveuSchwarz and Ramond models. The picture is manifestly dual, even for the Ramond model, and amplitudes with an arbitrary number of external fermions can be constructed. In all channels the only singularities are poles corresponding to the expected particles. There exist both qq and zero-quark mesons, which differ in the parity of the states with odd Neveu-Schwarz g-parity. Calculations of ff scattering amplitudes are performed. The results are B-functions multiplied by simple kinematical factors, and it is easily verified that the amplitudes possess all the necessary properties.

One loop mass renormalization of unstable particles in superstring theory

“…We discuss extension of this analysis to general external states in section 4 where we also give a justification of the procedure from string field theory and show that the results for the renormalized mass obtained this way agree for different versions of string field theory. We 2 Since the approach of [7] was motivated from light-cone string field theory [24,25], one could ask if we can directly work with the light-cone string field theory and impose the i prescription there. This would make the proof of unitarity more straightforward.…”

Strings in plane wave backgrounds

“…For example, the interaction vertex for the scattering of three strings depicted in Figure 1 is constructed with a Delta-functional enforcing world-sheet continuity. The func- tional approach [140,141,144,145] can be extended to the superstring [146,147,148,149]. Here the situation is slightly more complicated, but the basic principle governing the construction of interactions is very simple: the superalgebra has to be realized in the full interacting theory.…”

Superstring interactions in app-wave background

“…Then the solutions s, t and v will also be unchanged. 10 Now the derivation of the equations (4.24) and (4.25) follows quite trivially from the identities (4.21) and (4.23). Therefore, if we want to preserve these equations, we should look for stringy generalizations of IP and Λ which preserve the relations (4.21) and (4.23) as closely as possible.…”

“…Note that our calculation is purely on the 'string side,' although it is our hope to eventually compare with results from the 'field theory side.' Light-cone string field theory is an old subject, harking back to the work of Mandelstam [10,11] and extensively developed for the superstring by Green and Schwarz [12][13][14][15], and for the closed type IIB string by Green, Schwarz and Brink [8]. The light-cone formulation is especially appropriate for the pp-wave background because of the beautiful way in which light-cone 'string bits' naturally emerge in the field theory description [1] (see Figure 2).…”