Feynman Diagram 1
Basic Feynman diagram showing a dressed propagator (hatched vertex) connecting two external fields φₐ and φᵦ with incoming momentum p₁ and outgoing momentum p₂. The vertex represents the full momentum-dependent two-point Green's function G_k, which includes all quantum corrections. This is a fundamental building block for more complex quantum field theory calculations.
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LaTeX
feynman-diagram-1.tex (13 lines)
\documentclass[tikz]{standalone}
\usetikzlibrary{patterns}
\begin{document}
\begin{tikzpicture}
\draw (-2.25,0) node[left] {$\varphi_a$} -- (2.25,0) node[right] {$\varphi_b$};
\draw[->,yshift=5pt] (-2,0) -- (-1,0) node[midway,above] {$p_1$};
\draw[->,yshift=5pt] (1,0) -- (2,0) node[midway,above] {$p_2$};
\draw[fill=white,postaction={pattern=north east lines}] (0,0) circle (0.25) node[above=5pt] {$G_{k,ab}(p_1,p_2)$};
\end{tikzpicture}
\end{document}
Typst
feynman-diagram-1.typ (39 lines)
#import "@preview/cetz:0.3.4": canvas, draw
#import "@preview/modpattern:0.1.0": modpattern
#import draw: line, content, circle
#set page(width: auto, height: auto, margin: 8pt)
// Create hatched pattern for vertices
#let hatched = modpattern(
(.1cm, .1cm),
std.line(start: (0%, 100%), end: (100%, 0%), stroke: 0.5pt),
background: white,
)
#canvas({
// Define styles and constants
let arrow-style = (
mark: (end: "stealth", fill: black, scale: .5),
stroke: (thickness: 0.75pt),
)
// Draw main horizontal line
line((-2.25, 0), (2.25, 0), stroke: 1pt, name: "a-to-b")
// Add phi labels
content("a-to-b.start", $phi_a$, anchor: "east", padding: 3pt)
content("a-to-b.end", $phi_b$, anchor: "west", padding: 3pt)
// Add momentum arrows
line((-2, 0.15), (-1, 0.15), ..arrow-style, name: "p1")
content((rel: (0, 0.3), to: "p1.mid"), $p_1$)
line((1, 0.15), (2, 0.15), ..arrow-style, name: "p2")
content((rel: (0, 0.3), to: "p2.mid"), $p_2$)
// Draw vertex with hatched pattern
circle((0, 0), radius: 0.25, fill: hatched, name: "vertex")
content((rel: (0, 0.5), to: "vertex"), $G_(k,a b)(p_1,p_2)$)
})