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13 papers found.
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Semi-abelian Z-theory: NLSM+ϕ 3 from the open string

We continue our investigation of Z-theory, the second double-copy component of open-string tree-level interactions besides super-Yang-Mills (sYM). We show that the amplitudes of the extended non-linear sigma model (NLSM) recently considered by Cachazo, Cha, and Mizera are reproduced by the leading α ′-order of Z-theory amplitudes in the semi-abelian case. The extension refers to...

Non-abelian Z-theory: Berends-Giele recursion for the α ′-expansion of disk integrals

We present a recursive method to calculate the α ′ -expansion of disk integrals arising in tree-level scattering of open strings which resembles the approach of Berends and Giele to gluon amplitudes. Following an earlier interpretation of disk integrals as doubly partial amplitudes of an effective theory of scalars dubbed as Z-theory, we pinpoint the equation of motion of Z...

Abelian Z-theory: NLSM amplitudes and α ′ -corrections from the open string

In this paper we derive the tree-level S-matrix of the effective theory of Goldstone bosons known as the non-linear sigma model (NLSM) from string theory. This novel connection relies on a recent realization of tree-level open-superstring S-matrix pre-dictions as a double copy of super-Yang-Mills theory with Z-theory — the collection of putative scalar effective field theories...

Berends-Giele recursion for double-color-ordered amplitudes

Received: May Berends-Giele recursion for double-color-ordered Carlos R. Mafra 0 1 0 Einstein Drive , Princeton, NJ 08540 , U.S.A 1 School of Natural Sciences, Institute for Advanced Study Tree

One-loop superstring six-point amplitudes and anomalies in pure spinor superspace

We present the massless six-point one-loop amplitudes in the open and closed superstring using BRST cohomology arguments from the pure spinor formalism. The hexagon gauge anomaly is traced back to a class of kinematic factors in pure spinor superspace which were recently introduced as BRST pseudo-invariants. This complements previous work where BRST invariance arguments were used...

Berends-Giele recursions and the BCJ duality in superspace and components

The recursive method of Berends and Giele to compute tree-level gluon amplitudes is revisited using the framework of ten-dimensional super Yang-Mills. First, we prove that the pure spinor formula to compute SYM tree amplitudes derived in 2010 reduces to the standard Berends-Giele formula from the 80s when restricted to gluon amplitudes and additionally determine the fermionic...

Two-loop five-point amplitudes of super Yang-Mills and supergravity in pure spinor superspace

Supersymmetric integrands for the two-loop five-point amplitudes in tendimensional super Yang-Mills and type II supergravity are proposed. The kinematic numerators are manifestly local and satisfy the duality between color and kinematics described by Bern, Carrasco and Johansson. Our results are expected to reproduce the integrated two-loop amplitudes in dimensions D < 7. The UV...

Non-linear gauge transformations in D = 10 SYM theory and the BCJ duality

Recent progress on scattering amplitudes in super Yang-Mills and super-string theory benefitted from the use of multiparticle superfields. They universally capture tree-level subdiagrams, and their generating series solve the non-linear equations of ten-dimensional super Yang-Mills. We provide simplified recursions for multiparticle superfields and relate them to earlier...

The structure of n-point one-loop open superstring amplitudes

Carlos R. Mafra 1 Oliver Schlotterer 0 0 Max-Planck-Institut fur Gravitationsphysik, Albert-Einstein-Institut , Am Muhlenberg 1, 14476 Golm, Germany 1 DAMTP, University of Cambridge , Wilberforce

Multiparticle SYM equations of motion and pure spinor BRST blocks

Carlos R. Mafra 1 Oliver Schlotterer 0 0 Max-Planck-Institut fur Gravitationsphysik, Albert-Einstein-Institut , 14476 Potsdam, Germany 1 DAMTP, University of Cambridge Wilberforce Road , Cambridge

Elliptic multiple zeta values and one-loop superstring amplitudes

We investigate iterated integrals on an elliptic curve, which are a natural genus-one generalization of multiple polylogarithms. These iterated integrals coincide with the multiple elliptic polylogarithms introduced by Brown and Levin when constrained to the real line. At unit argument they reduce to an elliptic analogue of multiple zeta values, whose network of relations we...

Simplifying the tree-level superstring massless five-point amplitude

Carlos R. Mafra 0 0 Max-Planck-Institut fur Gravitationsphysik, Albert-Einstein-Institut , 14476 Golm, Germany We use the pure spinor formalism to obtain the supersymmetric massless fivepoint

The overall coefficient of the two-loop superstring amplitude using pure spinors

Humberto Gomez 1 Carlos R. Mafra 0 0 Max-Planck-Institut fur Gravitationsphysik, Albert-Einstein-Institut , Am Muhlenberg 1, 14476 Potsdam, Germany 1 Instituto de Fsica Teorica, UNESP - Universidade