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We take a fresh look at Feynman diagrams in the spinor-helicity formalism. Focusing on tree-level massless QED and QCD, we develop a new and conceptually simple graphical method for their calculation. In this pictorial method, which we dub…

High Energy Physics - Phenomenology · Physics 2020-11-03 Andrew Lifson , Christian Reuschle , Malin Sjodahl

The FormCalc package automates the computation of FeynArts amplitudes up to one loop including the generation of a Fortran code for the numerical evaluation of the squared matrix element. Major new or enhanced features in Version 5 are:…

High Energy Physics - Phenomenology · Physics 2009-11-11 T. Hahn , M. Rauch

Recently, we proposed a new approach for calculating Feynman graphs amplitude using the Gaussian representation for propagators which was proven to be exact in the limit of graphs having an infinite number of loops. Regge behavior was also…

High Energy Physics - Phenomenology · Physics 2015-06-25 Richard Hong Tuan

We present a new version 3.1 of the LanHEP software package. New features of the program include tools for the models with extra dimensions, implementation of the particle classes for FeynArts output and using templates with LanHEP…

High Energy Physics - Phenomenology · Physics 2010-05-12 A. Semenov

We introduce the Python program THALAS (TensorFlow Hydrodynamics Analysis for Lyman-Alpha Simulations), which maps baryon fields (baryon density, temperature, and velocity) to Ly$\alpha$ optical depth fields in both real space and redshift…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-24 Jupiter Ding , Benjamin Horowitz , Zarija Lukić

The compute efficiency of Monte-Carlo event generators for the Large Hadron Collider is expected to become a major bottleneck for simulations in the high-luminosity phase. Aiming at the development of a full-fledged generator for modern…

High Energy Physics - Phenomenology · Physics 2022-01-11 Enrico Bothmann , Walter Giele , Stefan Hoeche , Joshua Isaacson , Max Knobbe

We present the program package GoSam which is designed for the automated calculation of one-loop amplitudes for multi-particle processes in renormalisable quantum field theories. The amplitudes, which are generated in terms of Feynman…

The LanHEP program for Feynman rules generation in momentum representation is presented. It reads the Lagrangian written in a compact form, close to the one used in publications. It means that Lagrangian terms can be written with summation…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. V. Semenov

We present a new Mathematica package that provides a platform to perform multi-loop computations. ANATAR integrates several existing tools designed for higher-order computations. In particular, it uses QGRAF to generate Feynman diagrams and…

High Energy Physics - Phenomenology · Physics 2025-09-18 Claude Duhr , Pooja Mukherjee , Andres Vasquez

The scattering equation formalism is a general framework for calculation of amplitudes in theories of massless particles. We provide a detailed introduction to the 4D scattering equation framework accessible to non-experts, outline current…

High Energy Physics - Theory · Physics 2018-08-29 Joseph A. Farrow

Recently a new recursion relation for tree-level gluon amplitudes in gauge theory has been discovered. We solve this recursion to obtain explicit formulas for the closed set of amplitudes with arbitrarily many positive and negative helicity…

High Energy Physics - Theory · Physics 2009-11-11 Ruth Britto , Bo Feng , Radu Roiban , Marcus Spradlin , Anastasia Volovich

We present a simple technique that allows to generate Feynman diagrams for vector models with interactions of order $2n$ and similar models (Gross-Neveu, Thirring model), using a bootstrap equation that uses only the free field value of the…

High Energy Physics - Theory · Physics 2016-09-06 Sigurd Schelstraete , Henri Verschelde

We describe an efficient implementation of the BCFW recursion relations for tree-amplitudes in N=4 super Yang-Mills, which can generate analytic formulae for general N^kMHV colour-ordered helicity-amplitudes-which, in particular, includes…

High Energy Physics - Phenomenology · Physics 2010-11-11 Jacob L. Bourjaily

SARAH is a Mathematica package for building and studying supersymmetric models. It calculates for a given superpotential and gauge sector the full Lagrangian of a model. With the new version of SARAH it is possible to calculate…

High Energy Physics - Phenomenology · Physics 2010-04-22 Florian Staub

Pfaffian diagrams are formulated to represent gluon amplitudes computed from the Cachazo-He-Yuan (CHY) formula. They may be regarded as a systematic regrouping of Feynman diagrams after internal momenta are expanded and products of vertex…

High Energy Physics - Theory · Physics 2018-10-10 C. S. Lam

Feynman rules for the Standard Model including non-linear gauges are derived and implemented in the FeynArts package. The calculations using FeynArts with the new rules show that tree-level amplitudes are gauge invariant and that…

High Energy Physics - Phenomenology · Physics 2007-10-02 Jurgis Pasukonis

We present an upgraded version (denoted as version 2.0) of the program HELAC-Onia for the automated computation of heavy-quarkonium helicity amplitudes within non-relativistic QCD framework. The new code has been designed to include many…

High Energy Physics - Phenomenology · Physics 2015-07-14 Hua-Sheng Shao

MadAnalysis 5 is a new Python/C++ package facilitating phenomenological analyses that can be performed in the framework of Monte Carlo simulations of collisions to be produced in high-energy physics experiments. It allows, by means of a…

High Energy Physics - Phenomenology · Physics 2014-06-16 Eric Conte , Benjamin Fuks

GALA is a freely distributed Fortran code to derive automatically the atmospheric parameters (temperature, gravity, microturbulent velocity and overall metallicity) and abundances for individual species of stellar spectra using the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 A. Mucciarelli , E. Pancino , L. Lovisi , F. R. Ferraro , E. Lapenna

In this paper, we calculate higher point tree level vector amplitudes propagating in AdS$_4$. We use bulk perturbation theory to compute tree level Witten diagrams. We show that when these amplitudes are written in momentum space, they…

High Energy Physics - Theory · Physics 2019-02-13 Soner Albayrak , Savan Kharel
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