Quick Start Guide

This guide will get you started with tikz-feyn in minutes.

Basic Concepts

tikz-feyn diagrams are built from vertices and edges:

  • Vertices are points in space where particles meet

  • Edges are lines representing particle propagators

  • Diagrams are organized in columns for consistent layout

Your First Diagram

Let’s create a simple fermion propagator:

\documentclass{article}
\usepackage{tikz-feyn}
\begin{document}

\begin{tfeyn}
  \tfcol{i}      % Input vertex
  \tfcol{o}      % Output vertex
  \tf[f]{i,o}    % Fermion line from i to o
\end{tfeyn}

\end{document}

This creates two columns with one vertex each, connected by a fermion line.

Environments

tikz-feyn provides three environments for different contexts:

tfeyn (Display Mode)

For standalone diagrams:

\begin{tfeyn}
  % diagram commands
\end{tfeyn}

tfeynin (Inline Mode)

For diagrams within text:

The process
\begin{tfeynin}
  \tfcol{i}\tfcol{o}
  \tf[f]{i,o}
\end{tfeynin}
is important.

tfeynma (Math Mode)

For diagrams in equations:

\begin{equation}
  \mathcal{M} =
  \begin{tfeynma}
    \tfcol{i}\tfcol{o}
    \tf[f]{i,o}
  \end{tfeynma}
\end{equation}

Creating Columns

Use \tfcol to create columns of vertices:

\tfcol{vertex1, vertex2, vertex3}

Multiple vertices are separated by commas and arranged vertically.

Custom Spacing

Control the vertical spacing within a column:

\tfcol{i1, i2, i3}[1cm]  % 1cm between vertices

Position Offsets

Shift an entire column vertically:

\tfcol(0, 0.5cm){m1, m2}  % Shift column up by 0.5cm

Drawing Edges

Use \tf to connect vertices with particle propagators:

Basic Syntax

\tf[style]{vertex1, vertex2}

Examples:

\tf[f]{i,o}      % Fermion
\tf[p]{a,b}      % Photon
\tf[g]{v1,v2}    % Gluon

Available Styles

  • f or fermion - Fermion (line with arrow)

  • p or photon - Photon (wavy line)

  • w or wboson - W boson (coiled double line, 1pt)

  • z or zboson - Z boson (coiled double line, 2pt)

  • h or higgs - Higgs boson (dotted line)

  • g or gluon - Gluon (coiled line)

  • G or graviton - Graviton (double coiled line)

Intermediate Vertices

Create vertices between existing ones:

\begin{tfeyn}
  \tfcol{a1, a2}
  \tfcol{b1, b2}
  \tf[f]{a1, v1, a2}[r]  % Creates v1 to the right
  \tf[p]{v1, b1}
\end{tfeyn}

Direction Options

The third argument specifies where to create intermediate vertices:

  • r - Right

  • l - Left

  • u - Up

  • d - Down

Complete Example

Electron-positron scattering:

\documentclass{article}
\usepackage{tikz-feyn}
\begin{document}

\begin{tfeyn}
  % Create three columns
  \tfcol{i1, i2}              % Incoming particles
  \tfcol{m1, m2}              % Interaction vertices
  \tfcol{o1, o2}              % Outgoing particles

  % Connect vertices
  \tf[f]{i1, m1}              % Incoming electron
  \tf[f]{i2, m2}              % Incoming positron
  \tf[p]{m1, m2}              % Photon exchange
  \tf[f]{m1, o1}              % Outgoing electron
  \tf[f]{m2, o2}              % Outgoing positron
\end{tfeyn}

\end{document}

Loops and Arcs

Create self-energy diagrams and loops:

\begin{tfeyn}
  \tfcol{i}
  \tfcol{o}
  \tf[p]{i,o}              % Main propagator
  \tf[f, l]{i,o}           % Fermion loop (l = loop style)
\end{tfeyn}

Adjust loop shape:

\tf[f, l, looseness=2]{i,o}  % Larger loop

Customization

Combine with TikZ Styles

\tf[f, red]{i,o}             % Red fermion
\tf[p, blue, thick]{a,b}     % Thick blue photon
\tf[g, dashed]{v1,v2}        % Dashed gluon

Environment Parameters

All environments accept spacing parameters:

\begin{tfeyn}[column sep][row sep][h-int][v-int]
  % diagram
\end{tfeyn}

Example:

\begin{tfeyn}[3cm][1cm][0.8cm][0.4cm]
  % Wider, taller diagram
\end{tfeyn}

Next Steps