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Related papers: Simplifying one-loop amplitudes in superstring the…

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We consider N=1 SUSY gauge theory in six dimensions in components and show that provided the Dynkin indices of the matter fields representations satisfy the relation $\sum T(R)= C_2(G)$, the gauge sector is completely one-loop finite. In…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. I. Kazakov

We show that one-loop amplitudes in massless gauge theories can be determined from single cuts. By cutting a single propagator and putting it on-shell, the integrand of an n-point one-loop integral is transformed into an (n+2)-particle tree…

High Energy Physics - Theory · Physics 2008-12-25 E. W. Nigel Glover , Ciaran Williams

From general arguments, we show that one-loop n-point amplitudes in colourless theories satisfy a new type of reduction formula. These lead to the existence of cancellations beyond supersymmetry. Using such reduction relations we prove the…

High Energy Physics - Theory · Physics 2010-02-03 N. E. J. Bjerrum-Bohr , Pierre Vanhove

We obtain a color-kinematics-dual representation of the two-loop four-vector amplitude a general renormalizable massless $\mathcal{N}=1$ SYM theory, including internal matter as chiral supermultiplets. The integrand is constructed to be…

High Energy Physics - Theory · Physics 2023-12-29 Henrik Johansson , Gregor Kälin , Gustav Mogull , Bram Verbeek

The pure spinor formalism for the superstring has the advantage over the more conventional Ramond-Neveu-Schwarz formalism of being manifestly spacetime supersymmetric, which simplifies the computation of multiparticle and multiloop…

High Energy Physics - Theory · Physics 2025-03-06 Nathan Berkovits , Carlos R. Mafra

A class of supersymmetric (BPS saturated), static, spherically symmetric solutions of four-dimensional effective N=4 supersymmetric superstring vacua, which become massless at special points of moduli space, is studied in terms of the…

High Energy Physics - Theory · Physics 2009-09-17 Mirjam Cvetič , Donam Youm

The two-loop four-point amplitude of two massless SU(N) colored scalars and two color singlet operators with different virtuality described by a half-BPS and Konishi operators is calculated analytically in maximally supersymmetric…

High Energy Physics - Theory · Physics 2020-12-01 Taushif Ahmed , Prasanna K. Dhani

A first quantised approach to loop amplitudes based on the pure spinor particle is applied to the systematics of four-particle amplitudes in maximally supersymmetric field theories. Counting of fermionic zero modes allows the identification…

High Energy Physics - Theory · Physics 2011-03-28 Jonas Bjornsson , Michael B. Green

Perturbative spectra and related factorization properties of one-loop open string amplitudes in the presence of a constant external background B are analysed in detail. While the pattern of the closed string spectrum, obtained after a…

High Energy Physics - Theory · Physics 2009-11-10 A. Bassetto , A. Torrielli , R. Valandro

By using the hybrid formalism, superstrings in four-dimensional NS-NS plane waves are studied in a manifest supersymmetric manner. This description of the superstring is obtained by a field redefinition of the RNS worldsheet fields and…

High Energy Physics - Theory · Physics 2009-11-10 Hiroshi Kunitomo

Superstring perturbation theory based on the 1PI effective theory approach has been useful for addressing the problem of mass renormalization and vacuum shift. We derive Ward identities associated with space-time supersymmetry…

High Energy Physics - Theory · Physics 2016-01-27 Ashoke Sen

Under the assumption of a CSW generalization to loop amplitudes in N=4 SYM, (1) We prove that, formally the S-matrix is superconformal invariant to any loop order, and (2) We argue that superconformal symmetry survives regularization. More…

High Energy Physics - Theory · Physics 2009-09-28 Amit Sever , Pedro Vieira

In this note we derive an explicit modular invariant formula for the two loop 4-point amplitude in superstring theory in terms of a multiple integral (7 complex integration variables) over the complex plane which is shown to be convergent.…

High Energy Physics - Theory · Physics 2009-10-31 Roberto Iengo , Chuan-Jie Zhu

We take a major step towards computing $D$-dimensional one-loop amplitudes in general gauge theories, compatible with the principles of unitarity and the color-kinematics duality. For $n$-point amplitudes with either supersymmetry…

High Energy Physics - Theory · Physics 2023-02-20 Alex Edison , Song He , Henrik Johansson , Oliver Schlotterer , Fei Teng , Yong Zhang

Scattering amplitudes in three-dimensional N=6 Chern-Simons theory are shown to be non-invariant with respect to the free representation of the osp(6|4) symmetry generators. At tree and one-loop level these "anomalous" terms occur only for…

High Energy Physics - Theory · Physics 2012-11-06 Till Bargheer , Niklas Beisert , Florian Loebbert , Tristan McLoughlin

In theories of closed oriented superstrings, the one loop amplitude is given by a single diagram, with the topology of a torus. Its interpretation had remained obscure, because it was formally real, converged only for purely imaginary…

High Energy Physics - Theory · Physics 2010-11-01 E. D'Hoker , D. H. Phong

In this paper a supersymmetric version of a generalized unitarity cut method in application to MHV and NMHV for form factors of operators from the N=4 SYM stress-tensor current supermultiplet $T^{AB}$ at one loop is discussed. The explicit…

High Energy Physics - Theory · Physics 2015-06-04 L. V. Bork

We generalize to the eleven-dimensional superparticle Berkovits' prescription for loop computations in the pure spinor approach to covariant quantization of the superstring. Using these ten- and eleven-dimensional results, we compute…

High Energy Physics - Theory · Physics 2009-11-10 L. Anguelova , P. A. Grassi , P. Vanhove

In this paper we study the one- and two-loop corrections to the four-point amplitude of N=6 Chern-Simons matter theory. Using generalized unitarity methods we express the one- and two-loop amplitudes in terms of dual-conformal integrals.…

High Energy Physics - Theory · Physics 2015-05-28 Wei-Ming Chen , Yu-tin Huang

The method of the calculation of the multi-loop superstring amplitudes is proposed. The amplitudes are calculated from the equations that are none other than Ward identities. They are derived from the requirement that the discussed…

High Energy Physics - Theory · Physics 2014-11-18 G. S. Danilov