scholarly journals Spinning amplitudes from scalar amplitudes

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Mahesh K. N. Balasubramanian ◽  
Raj Patil ◽  
Arnab Rudra
Keyword(s):  
Scattering Amplitudes ◽  
Jacobi Polynomials ◽  
Tree Level ◽  
Angular Distributions ◽  
Systematic Method ◽  
Massive Spin

Abstract We provide a systematic method to compute tree-level scattering amplitudes with spinning external states from amplitudes with scalar external states in arbitrary spacetime dimensions. We write down analytic answers for various scattering amplitudes, including the four graviton amplitude due to the massive spin J exchange. We verify the results by computing angular distributions in 3 + 1 dimensions using various identities involving Jacobi polynomials.

scholarly journals Extracting bigravity from string theory

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Dieter Lüst ◽  
Chrysoula Markou ◽  
Pouria Mazloumi ◽  
Stephan Stieberger
Keyword(s):  
Scattering Amplitudes ◽  
String Theory ◽  
Open String ◽  
Closed String ◽  
Bimetric Theory ◽  
Low Energy ◽  
Tree Level ◽  
Dark Matter Candidate ◽  
Massive Spin ◽  
Numerical Coefficient

Abstract The origin of the graviton from string theory is well understood: it corresponds to a massless state in closed string spectra, whose low-energy effective action, as extracted from string scattering amplitudes, is that of Einstein-Hilbert. In this work, we explore the possibility of such a string-theoretic emergence of ghost-free bimetric theory, a recently proposed theory that involves two dynamical metrics, that around particular backgrounds propagates the graviton and a massive spin-2 field, which has been argued to be a viable dark matter candidate. By choosing to identify the latter with a massive spin-2 state of open string spectra, we compute tree-level three-point string scattering amplitudes that describe interactions of the massive spin-2 with itself and with the graviton. With the mass of the external legs depending on the string scale, we discover that extracting the corresponding low-energy effective actions in four spacetime dimensions is a subtle but consistent process and proceed to appropriately compare them with bimetric theory. Our findings consist in establishing that string and bimetric theory provide to lowest order the same set of two-derivative terms describing the interactions of the massive spin-2 with itself and with the graviton, albeit up to numerical coefficient discrepancies, a fact that we analyze and interpret. We conclude with a mention of future investigations.

TREE DIAGRAMS IN WITTEN’S SUPERSTRING FIELD THEORY

1989 ◽  
Vol 04 (21) ◽  
pp. 2063-2071
Author(s):  
GEORGE SIOPSIS
Keyword(s):  
Field Theory ◽  
Scattering Amplitudes ◽  
Invariant Theory ◽  
Higher Order ◽  
Contact Term ◽  
Tree Level ◽  
Gauge Invariant

It is shown that the contact term discovered by Wendt is sufficient to ensure finiteness of all tree-level scattering amplitudes in Witten’s field theory of open superstrings. Its inclusion in the action also leads to a gauge-invariant theory. Thus, no additional higher-order counterterms in the action are needed.

scholarly journals Polarization in low energy kaon–hyperon interaction

2020 ◽  
Vol 29 (03) ◽  
pp. 2050013 ◽  
Author(s):  
M. G. L. Nogueira-Santos ◽  
C. C. Barros
Keyword(s):  
Scattering Amplitudes ◽  
Chiral Lagrangians ◽  
Low Energy ◽  
Angular Distributions

In this paper, we study the low energy kaon–hyperon interaction considering effective chiral Lagrangians that include kaons, [Formula: see text] mesons, hyperons and the corresponding resonances. The scattering amplitudes are calculated and then we determine the angular distributions and polarizations.

scholarly journals Scattering amplitudes of massive spin-2 Kaluza-Klein states grow only as O(s)

2020 ◽  
Vol 101 (5) ◽  
Author(s):  
R. Sekhar Chivukula ◽  
Dennis Foren ◽  
Kirtimaan A. Mohan ◽  
Dipan Sengupta ◽  
Elizabeth H. Simmons
Keyword(s):  
Scattering Amplitudes ◽  
Massive Spin ◽  
Kaluza Klein

scholarly journals PROBING THE FROISSART BOUND FOR MODELS WITH CHARGED VECTOR FIELDS IN D=3

1994 ◽  
Vol 09 (18) ◽  
pp. 1695-1700 ◽  
Author(s):  
O.M. DEL CIMA
Keyword(s):  
Asymptotic Behavior ◽  
Scattering Amplitudes ◽  
Gauge Field ◽  
Vector Fields ◽  
Three Dimensional ◽  
Tree Level ◽  
Abelian Gauge ◽  
Gauge Invariant ◽  
Maxwell Fields ◽  
Chern Simons

One discusses the tree-level unitarity and presents asymptotic behavior of scattering amplitudes for three-dimensional gauge-invariant models where complex Chern- Simons-Maxwell fields (with and without a Proca-like mass) are coupled to an Abelian gauge field.

scholarly journals 10D super-Yang-Mills scattering amplitudes from its pure spinor action

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Maor Ben-Shahar ◽  
Max Guillen
Keyword(s):  
Scattering Amplitudes ◽  
Jacobi Identity ◽  
Gauge Condition ◽  
Tree Level ◽  
Pure Spinor ◽  
Yang Mills

Abstract Using the pure spinor master action for 10D super-Yang-Mills in the gauge b0V = QΞ, tree-level scattering amplitudes are calculated through the perturbiner method, and shown to match those obtained from pure spinor CFT techniques. We find kinematic numerators made of nested b-ghost operators, and show that the Siegel gauge condition b0V = 0 gives rise to color-kinematics duality satisfying numerators whose Jacobi identity follows from the Jacobi identity of a kinematic algebra.

scholarly journals Tree-level splitting amplitudes for a gluon into four collinear partons

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Vittorio Del Duca ◽  
Claude Duhr ◽  
Rayan Haindl ◽  
Achilleas Lazopoulos ◽  
Martin Michel
Keyword(s):  
Scattering Amplitudes ◽  
Strong Coupling ◽  
Strong Coupling Constant ◽  
Tree Level ◽  
Leading Order ◽  
Coupling Constant ◽  
Level Splitting ◽  
Infrared Behaviour

Abstract We compute in conventional dimensional regularisation the tree-level splitting amplitudes for a gluon parent which splits into four collinear partons. This is part of the universal infrared behaviour of the QCD scattering amplitudes at next-to-next-to-next-to-leading order (N3LO) in the strong coupling constant. Combined with our earlier results for a quark parent, this completes the set of tree-level splitting amplitudes required at this order. We also study iterated collinear limits where a subset of the four collinear partons become themselves collinear.

scholarly journals The boostless bootstrap and BCFW momentum shifts

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
David Stefanyszyn ◽  
Jakub Supeł
Keyword(s):  
Scattering Amplitudes ◽  
Tree Level ◽  
Particle Interactions ◽  
Particle Scattering ◽  
Consistency Check ◽  
Independent Verification ◽  
Lorentz Boosts

Abstract In a recent paper [1], three-particle interactions without invariance under Lorentz boosts were constrained by demanding that they yield tree-level four-particle scattering amplitudes with singularities as dictated by unitarity and locality. In this brief note, we show how to obtain an independent verification and consistency check of these boostless bootstrap results using BCFW momentum shifts. We point out that the constructibility criterion, related to the behaviour of the deformed amplitude at infinite BCFW parameter z, is not strictly necessary to obtain non-trivial constraints for the three-particle interactions.

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