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Related papers: Simplifying the Tree-level Superstring Massless Fi…

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The tree-level amplitude of six massless open strings is computed using the pure spinor formalism. The OPE poles among integrated and unintegrated vertices can be efficiently organized according to the cohomology of pure spinor superspace.…

High Energy Physics - Theory · Physics 2015-03-17 Carlos R. Mafra , Oliver Schlotterer , Stephan Stieberger , Dimitrios Tsimpis

We compute the massless five-point amplitude of open superstrings using the non-minimal pure spinor formalism and obtain a simple kinematic factor in pure spinor superspace, which can be viewed as the natural extension of the kinematic…

High Energy Physics - Theory · Physics 2009-04-13 Carlos R. Mafra , Christian Stahn

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…

High Energy Physics - Theory · Physics 2023-05-24 Carlos R. Mafra , Oliver Schlotterer

Using the pure spinor formalism we prove identities which relate the tree-level, one-loop and two-loop kinematic factors for massless four-point amplitudes. From these identities it follows that the complete supersymmetric one- and two-loop…

High Energy Physics - Theory · Physics 2014-11-18 Carlos R. Mafra

We construct the unintegrated vertex operator at the first mass level of the open superstring from the OPE of massless vertices. Using BRST cohomology manipulations, the tree amplitude of two massless and one massive state is rewritten in…

High Energy Physics - Theory · Physics 2025-03-06 Sitender Pratap Kashyap , Carlos R. Mafra , Mritunjay Verma , Luis Ypanaqué

We provide a prescription for computing two-point tree amplitudes in the pure spinor formalism that are finite and agree with the corresponding expression in the field theories. In [arXiv:1906.06051v1-arXiv:1909.03672v3], same results were…

High Energy Physics - Theory · Physics 2025-01-15 Sitender Pratap Kashyap

We develop a pure spinor worldline formalism for computing tree-level scattering amplitudes in 11D supergravity. Focusing first on the 4-point amplitude, we demonstrate that our prescription is consistent with BRST symmetry and gauge…

High Energy Physics - Theory · Physics 2025-12-11 Max Guillen , Marcelo dos Santos , Eggon Viana

By analogy with the formula for the massless string disk amplitudes, we define massive field-theory tree amplitudes and conjecture that the BRST cohomology structure of pure spinor superspace fixes their form. We give evidence by deriving…

High Energy Physics - Theory · Physics 2024-07-17 Carlos R. Mafra

This thesis discusses how the pure spinor formalism can be used to efficiently compute superstring scattering amplitudes. We emphasize the pure spinor superspace form of the kinematic factors, where the simplifying features of this language…

High Energy Physics - Theory · Physics 2009-03-26 Carlos R. Mafra

We calculate tree level scattering amplitudes for open strings using the NSR formalism. We present a streamlined symmetry-based and pedagogical approach to the computations, which we first develop by checking two-, three-, and four-point…

High Energy Physics - Theory · Physics 2016-08-22 Katrin Becker , Melanie Becker , Ilarion V. Melnikov , Daniel Robbins , Andrew B. Royston

In order to check the definite amplitude and the exact zero result of the amplitude of three massless points $(CAA)$ in both string theory and field theory side for $p=n$ case and to find all gauge field couplings to R-R closed string, we…

High Energy Physics - Theory · Physics 2011-07-26 Ehsan Hatefi

A simple BRST-closed expression for the color-ordered super-Yang-Mills 5-point amplitude at tree-level is proposed in pure spinor superspace and shown to be BRST-equivalent to the field theory limit of the open superstring 5-pt amplitude.…

High Energy Physics - Theory · Physics 2010-11-26 Carlos R. Mafra

We use Pure Spinor string theory to construct suitable kinematical factors which explicitly satisfy the Kleiss-Kuijf (KK) relations. Using the formula conceived by Bern et al. and employed by us for 4- and 5-point amplitudes in a previous…

High Energy Physics - Theory · Physics 2011-11-03 P. A. Grassi , A. Mezzalira , L. Sommovigo

Using BRST cohomology properties in pure spinor superspace and identities for OPE brackets of non-free fields, we obtain a new compact nested-bracket representation of massive tree-level three-point open-string amplitudes in which Moebius…

High Energy Physics - Theory · Physics 2026-04-02 Chen Huang , Carlos R. Mafra , Yi-Xiao Tao

Some time ago the bosonic and fermionic 4-field terms of the non-abelian low energy effective action of the open superstring were obtained, to all order in $\alpha'$. This was done at tree level by directly generalizing the abelian case,…

High Energy Physics - Theory · Physics 2011-07-19 Luiz Antonio Barreiro , Ricardo Medina

The exact symmetry identities among four-point tree-level amplitudes of bosonic open string theory as derived by G. W. Moore are re-examined. The main focuses of this work are: (1) Explicit construction of kinematic configurations and a new…

High Energy Physics - Theory · Physics 2014-06-02 Chuan-Tsung Chan , Shoichi Kawamoto , Dan Tomino

We use the non-minimal pure spinor formalism to compute in a super-Poincare covariant manner the four-point massless one and two-loop open superstring amplitudes, and the gauge anomaly of the six-point one-loop amplitude. All of these…

High Energy Physics - Theory · Physics 2009-11-11 Nathan Berkovits , Carlos R. Mafra

We present a prescription for computing tree-level scattering amplitudes in 10D super-Yang-Mills (SYM) theory using the pure spinor worldline formalism. The pure spinor formalism has proven to be a powerful framework for studying…

High Energy Physics - Theory · Physics 2025-12-11 Max Guillen , Marcelo dos Santos , Eggon Viana

We analyze an alternative prescription for computing tree level scattering amplitudes in the pure spinor superstring. Proposed by Berkovits, and inspired by an earlier work by Lee and Siegel, it bypasses the traditional ghost number three…

High Energy Physics - Theory · Physics 2025-11-21 Thales Azevedo , Alessandro Georgoudis , Renann Lipinski Jusinskas , Sitender Pratap Kashyap

Using the pure spinor formalism in part I [1] we compute the complete tree-level amplitude of N massless open strings and find a striking simple and compact form in terms of minimal building blocks: the full N-point amplitude is expressed…

High Energy Physics - Theory · Physics 2011-06-15 Carlos R. Mafra , Oliver Schlotterer , Stephan Stieberger
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