Related papers: Form factors from string amplitudes

We derive a minimal set of Feynman rules for the loop amplitudes in unitary models of closed strings, whose target space is a simply laced (extended) Dynkin diagram. The string field Feynman graphs are composed of propagators, vertices…

We study bosonic closed string scattering amplitudes in the high-energy limit. We find that the methods of decoupling of high-energy zero-norm states and the high-energy Virasoro constraints, which were adopted in the previous works to…

We quantize the open string in an arbitrary constant magnetic field with a non factorized metric on a torus. We then discuss carefully the vertexes which describe the emission of dipole open strings and closed strings in the non compact…

We prove that all open string theory disc amplitudes in a flat background obey Britto-Cachazo-Feng-Witten (BCFW) on-shell recursion relations, up to a possible reality condition on a kinematic invariant. Arguments that the same holds for…

High energy fixed angle scattering is studied in matrix string theory. The saddle point world sheet configurations, which give the dominant contributions to the string theory amplitude, are taken as classical backgrounds in matrix string…

We show that the scattering amplitude of four open string scalars or tachyons on the world-volume of a D$_p$-brane in the bosonic string theory can be written in a universal form. The difference between this amplitude and the corresponding…

We study gauge invariant operators of open string field theory and find a precise correspondence with on-shell closed strings. We provide a detailed proof of the gauge invariance of the operators and a heuristic interpretation of their…

The nonperturbative $1\to N$ tachyon scattering amplitude in 2D type 0A string theory is computed. The probability that $N$ particles are produced is a monotonically decreasing function of $N$ whenever $N$ is large enough that statistical…

We discover a stringy scaling behavior for a class of n-point Regge string scattering amplitudes (RSSA). The number of independent kinematics variables is found to be reduced by dim M.

We give a comprehensive review of recent developments on using the pure spinor formalism to compute massless superstring scattering amplitudes at tree level. The main results of the pure spinor computations are placed into the context of…

We consider the tree-level scattering amplitudes in the NS-NS (Neveu-Schwarz) massless sector of closed superstrings in the case where one external state becomes soft. We compute the amplitudes generically for any number of dimensions and…

We explicitly compute the Compton amplitude for the scattering of a photon and a (massless) ``electron/positron'' at tree level and one loop, in a four-dimensional fermionic heterotic string model. We comment on the relationship between the…

We consider string theory on AdS_3 in terms of the Wakimoto free field representation. The scattering amplitudes for N unitary tachyons are analysed in the factorization limit and the poles corresponding to the mass-shell conditions for…

The newly discovered splitting behavior of tree-level scattering amplitudes of particles and strings has been expressed in terms of currents containing one off-shell leg. In this work, we explain how to obtain on-shell representations of…

Superstring scattering from orientifold planes requires considering string amplitudes on world-sheets with crosscaps with the lowest order case (in string coupling constant) having the topology of the real projective plane. While amplitudes…

Very recently in arXiv:0705.0303 Alday and Maldacena gave a string theory prescription for computing (all) planar amplitudes in N=4 supersymmetric gauge theory at strong coupling using the AdS/CFT correspondence. These amplitudes are…

Using string scattering amplitudes of open bosonic string on a single $D$-brane, we construct a local field theoretical action for tachyon fields. Cubic local interactions between various particles, belonging to the particle spectrum of…

We study the scattering amplitudes in the N=2 minimal string or equivalently in the N=4 topological string on ALE spaces. We find an interesting connection between the tree level amplitudes of the N=2 minimal string and those of the (1,n)…

A prescription is presented to construct manifestly gauge invariant tree-level scattering amplitudes with one or two off-shell initial-state gluons for processes with arbitrary particles in the final state, which allows for calculations…

In {\em Phys.\ Lett.} {\bf B 660}, 583 (2008), it was proposed that the D-brane geometry could be produced by open string quantum effects. In an effort to verify the proposal, we consider scattering amplitudes involving {\em massive} open…