相关论文: The off-shell Veneziano amplitude in Schnabl gauge
We consider the Veneziano amplitude for the scattering of gluons in type IIB string theory on $AdS_5 \times S^5/\mathbb{Z}_2$ in the presence of D7 branes. On general grounds curvature corrections around flat space can be thought of as…
A systematic construction of superstring scattering amplitudes for $N$ massless NS bosons to two loop order is given, based on the projection of supermoduli space onto super period matrices used earlier for the superstring measure in the…
Off-shell interactions for localized closed-string tachyons in C/Z_N superstring backgrounds are analyzed and a conjecture for the effective height of the tachyon potential is elaborated. At large N, some of the relevant tachyons are nearly…
In this paper we consider soft high-energy parton-parton scattering processes in gauge theories, i.e., elastic scattering processes involving partons at very high squared energies in the center of mass and small squared transferred…
We compute three and four point functions of the non-BPS scattering amplitudes, including a closed string Ramond-Ramond, gauge/scalar and tachyon in type IIA (IIB) superstring theories. We then discover a unique expansion for tachyon…
We study on-shell scattering amplitudes for continuous-spin particles (CSPs). Poincar\'e invariance, little-group $ISO(2)$ covariance, analyticity, and on-shell factorisation (unitarity) impose stringent conditions on these amplitudes. We…
We develop further a new geometrical model of a discretized string, proposed in [1] and establish its basic physical properties. The model can be considered as the natural extention of the usual Feynman amplitude of the random walks to…
The fermion propagators in the fivebrane background of type II superstring theories are calculated. The propagator can be obtained by explicitly evaluating the transition amplitude between two specific NS-R boundary states by the propagator…
We first propose a general method to construct the complete set of on-shell operator bases involving massive particles with any spins. To incorporate the non-abelian little groups of massive particles, the on-shell scattering amplitude…
We derive a general expression for on-shell recursion relations of closed string tree-level amplitudes. Starting with the string amplitudes written in the form of the Koba-Nielsen integral, we apply the BCFW shift to deform them. In…
We present a general method of constructing unfactorizable on-shell amplitudes (amplitude basis), and build up their one-to-one correspondence to the independent and complete operator basis in effective field theory (EFT). We apply our…
We emphasize that scattering amplitudes of a wide class of models to any order in the coupling are constructible by on-shell tree subamplitudes. This follows from the Feynman-tree theorem combined with BCFW on-shell recursion relations. In…
We explicitly show how the chiral superstring amplitudes can be obtained through factorisation of the higher genus chiral measure induced by suitable degenerations of Riemann surfaces. This powerful tool also allows to derive, at any…
Beyond standard model (BSM) particles should be included in effective field theory in order to compute the scattering amplitudes involving these extra particles. We formulate an extension of Higgs effective field theory which contains…
The momemtum dependence of the off-shell $\rho$-$\omega$ mixing amplitude is calculated through a two-quark loop diagram, using non-perturbative meson-quark vertex functions for the $\rho$ and $\omega$ mesons, as well as non-perturbative…
We calculate the glueball-fermion hard-scattering amplitude from the dilaton-dilatino closed string scattering amplitude in type IIB superstring theory, in the framework of the gauge/string theory duality. We investigate its high-energy…
We establish the general off-shell structure of the three neutral gauge boson self-couplings V1*V2*V3*, with applications to the Z*Z*Z*, Z*Z*gamma*, gamma*gamma*Z* cases. New coupling forms appear which do not exist when two gauge bosons…
We consider the interactions of strings on T-folds from the world-sheet point of view which are exact in $\alpha'$. As a concrete example, we take a model where the internal torus at the so(8) enhancement point is twisted by T-duality…
I report on recent advancements regarding calculations that require initial-state partons with non-vanishing transverse momentum, causing it to be space-like and thus off-shell.
We write the vertex operators of massless NS-NS and RR states of Type II superstring theory in the presence of Orientifold p-planes. They include the usual vertex operators of Type II theory and their images. We then calculate the two-point…