A Feynman diagram visualizes interactions between subatomic particles in quantum field theory. Different line styles represent different particle types: straight lines for fermions (electrons, quarks), wavy lines for photons, curly/looped lines for gluons, and dashed lines for scalar bosons (e.g., Higgs). Lines meet at vertices representing interaction points. Invented by Richard Feynman, these diagrams are both a computational tool and a cultural icon of modern physics.
""" anyplot.ai
feynman-basic: Feynman Diagram for Particle Interactions
Library: plotly 6.7.0 | Python 3.13.13
Quality: 89/100 | Updated: 2026-06-03
"""
import os
import numpy as np
import plotly.graph_objects as go
# Theme tokens
THEME = os.getenv("ANYPLOT_THEME", "light")
PAGE_BG = "#FAF8F1" if THEME == "light" else "#1A1A17"
ELEVATED_BG = "#FFFDF6" if THEME == "light" else "#242420"
INK = "#1A1A17" if THEME == "light" else "#F0EFE8"
INK_SOFT = "#4A4A44" if THEME == "light" else "#B8B7B0"
INK_MUTED = "#6B6A63" if THEME == "light" else "#A8A79F"
# Imprint palette — particle type colors
# Semantic exception: fermion lines use #4467A3 (Imprint blue) rather than #009E73.
# Blue = universally established color for electron/fermion lines in Feynman diagram
# tools (FeynCalc, JaxoDraw, TikZ-Feynman) — a recognized physics-domain convention
# analogous to financial red/green. Z boson (vector) takes #009E73 as second series.
COLORS = {
"fermion": "#4467A3", # Imprint blue — electrons / muons (physics convention)
"vector": "#009E73", # Imprint green — Z boson (vector, wavy)
"photon": "#AE3030", # Imprint matte red — photons (wavy)
"boson": "#C475FD", # Imprint lavender — Higgs scalar (dashed)
}
LINE_W = 4
# Data — Higgs-strahlung: e+e- → Z* → ZH → μ+μ- γγ (lepton collider)
# Showcases all 4 line types: fermion (straight + arrow), vector Z (wavy),
# photon (wavy), scalar H (dashed)
vertices = {
"v1": (0.18, 0.50), # e+e- annihilation → Z*
"v2": (0.50, 0.50), # Z* → ZH production
"v3": (0.82, 0.78), # Z → μ+μ- decay
"v4": (0.78, 0.22), # H → γγ decay
}
propagators = [
{"from": (0.0, 0.72), "to": "v1", "type": "fermion", "label": "e⁻"},
{"from": (0.0, 0.28), "to": "v1", "type": "fermion", "label": "e⁺", "anti": True},
{"from": "v1", "to": "v2", "type": "vector", "label": "Z*"},
{"from": "v2", "to": "v3", "type": "vector", "label": "Z"},
{"from": "v2", "to": "v4", "type": "boson", "label": "H"},
{"from": "v3", "to": (1.0, 0.96), "type": "fermion", "label": "μ⁻"},
{"from": "v3", "to": (1.0, 0.60), "type": "fermion", "label": "μ⁺", "anti": True},
{"from": "v4", "to": (1.0, 0.38), "type": "photon", "label": "γ"},
{"from": "v4", "to": (1.0, 0.04), "type": "photon", "label": "γ"},
]
# Label offsets (dx, dy) from propagator midpoint
label_offsets = [
(-0.04, 0.06), # e⁻
(-0.04, -0.06), # e⁺
(0.00, 0.07), # Z*
(0.00, 0.07), # Z
(0.00, -0.07), # H
(-0.04, 0.05), # μ⁻
(-0.04, -0.05), # μ⁺
(-0.04, 0.05), # γ upper
(-0.04, -0.05), # γ lower
]
fig = go.Figure()
for i, prop in enumerate(propagators):
p0 = vertices[prop["from"]] if isinstance(prop["from"], str) else prop["from"]
p1 = vertices[prop["to"]] if isinstance(prop["to"], str) else prop["to"]
color = COLORS[prop["type"]]
dx, dy = p1[0] - p0[0], p1[1] - p0[1]
length = np.sqrt(dx**2 + dy**2)
ptype = prop["type"]
if ptype == "fermion":
fig.add_trace(
go.Scatter(
x=[p0[0], p1[0]],
y=[p0[1], p1[1]],
mode="lines",
line={"color": color, "width": LINE_W},
showlegend=False,
hovertemplate=f"<b>{prop['label']}</b><extra></extra>",
)
)
mx, my = (p0[0] + p1[0]) / 2, (p0[1] + p1[1]) / 2
ndx, ndy = dx / length, dy / length
if prop.get("anti"):
ndx, ndy = -ndx, -ndy # antiparticle: arrow reversed
fig.add_annotation(
x=mx + 0.018 * ndx,
y=my + 0.018 * ndy,
ax=mx - 0.05 * ndx,
ay=my - 0.05 * ndy,
xref="x",
yref="y",
axref="x",
ayref="y",
showarrow=True,
arrowhead=3,
arrowsize=2.5,
arrowwidth=3.5,
arrowcolor=color,
text="",
)
elif ptype in ("photon", "vector"):
t = np.linspace(0, 1, 400)
perp_x, perp_y = -dy / length, dx / length
amp = 0.030
freq = 10 if ptype == "photon" else 7 # Z slightly fewer oscillations
taper = np.minimum(t / 0.07, 1.0) * np.minimum((1 - t) / 0.07, 1.0)
wave = amp * np.sin(2 * np.pi * freq * t) * taper
fig.add_trace(
go.Scatter(
x=p0[0] + t * dx + wave * perp_x,
y=p0[1] + t * dy + wave * perp_y,
mode="lines",
line={"color": color, "width": LINE_W},
showlegend=False,
hovertemplate=f"<b>{prop['label']}</b><extra></extra>",
)
)
elif ptype == "boson":
fig.add_trace(
go.Scatter(
x=[p0[0], p1[0]],
y=[p0[1], p1[1]],
mode="lines",
line={"color": color, "width": LINE_W, "dash": "10px,6px"},
showlegend=False,
hovertemplate=f"<b>{prop['label']}</b><extra></extra>",
)
)
# Particle label at propagator midpoint + offset
lx = (p0[0] + p1[0]) / 2 + label_offsets[i][0]
ly = (p0[1] + p1[1]) / 2 + label_offsets[i][1]
fig.add_annotation(
x=lx,
y=ly,
text=f"<b>{prop['label']}</b>",
showarrow=False,
font={"size": 22, "color": color, "family": "serif"},
xanchor="center",
yanchor="middle",
)
# Vertex dots (theme-adaptive ink color)
for name, (vx, vy) in vertices.items():
fig.add_trace(
go.Scatter(
x=[vx],
y=[vy],
mode="markers",
marker={"size": 16, "color": INK, "line": {"width": 2.5, "color": PAGE_BG}},
showlegend=False,
hovertemplate=f"<b>Vertex {name}</b><br>Interaction point<extra></extra>",
)
)
# Legend — 4 particle types with miniature line samples, horizontal row at bottom
leg_items = [
("fermion", "Fermion (straight)"),
("vector", "Z boson (wavy)"),
("photon", "Photon (wavy)"),
("boson", "Higgs (dashed)"),
]
legend_ts = np.linspace(0, 1, 200)
legend_taper = np.minimum(legend_ts / 0.1, 1.0) * np.minimum((1 - legend_ts) / 0.1, 1.0)
lw_len = 0.060
x_starts = [0.04, 0.27, 0.52, 0.75]
y_leg = -0.065
for j, (ptype, desc) in enumerate(leg_items):
lx = x_starts[j]
ly = y_leg
col = COLORS[ptype]
if ptype == "fermion":
fig.add_shape(type="line", x0=lx, y0=ly, x1=lx + lw_len, y1=ly, line={"color": col, "width": 3})
fig.add_annotation(
x=lx + lw_len * 0.62,
y=ly,
ax=lx + lw_len * 0.38,
ay=ly,
xref="x",
yref="y",
axref="x",
ayref="y",
showarrow=True,
arrowhead=3,
arrowsize=1.8,
arrowwidth=2.5,
arrowcolor=col,
text="",
)
elif ptype == "boson":
fig.add_shape(
type="line", x0=lx, y0=ly, x1=lx + lw_len, y1=ly, line={"color": col, "width": 3, "dash": "10px,6px"}
)
else:
freq_leg = 5 if ptype == "photon" else 4
theta_s = 2 * np.pi * freq_leg * legend_ts
px = lx + legend_ts * lw_len
py = ly + 0.011 * np.sin(theta_s) * legend_taper
fig.add_trace(
go.Scatter(x=px, y=py, mode="lines", line={"color": col, "width": 2.5}, showlegend=False, hoverinfo="skip")
)
fig.add_annotation(
x=lx + lw_len + 0.010,
y=ly,
text=desc,
showarrow=False,
font={"size": 14, "color": col},
xanchor="left",
yanchor="middle",
)
# Time axis arrow (bottom of diagram)
fig.add_annotation(
x=0.68,
y=-0.12,
ax=0.04,
ay=-0.12,
xref="x",
yref="y",
axref="x",
ayref="y",
showarrow=True,
arrowhead=2,
arrowsize=2,
arrowwidth=2,
arrowcolor=INK_MUTED,
text="",
)
fig.add_annotation(
x=0.36, y=-0.145, text="<i>time</i>", showarrow=False, font={"size": 18, "color": INK_MUTED}, xanchor="center"
)
# Title: 62 chars — under 67, default 16px applies, no scaling needed
title = "Higgs-strahlung · feynman-basic · python · plotly · anyplot.ai"
fig.update_layout(
autosize=False,
margin={"l": 40, "r": 40, "t": 70, "b": 40},
paper_bgcolor=PAGE_BG,
plot_bgcolor=PAGE_BG,
font={"color": INK, "family": "serif"},
title={"text": title, "font": {"size": 16, "family": "serif"}, "x": 0.5, "xanchor": "center"},
xaxis={"visible": False, "range": [-0.06, 1.10], "fixedrange": True},
yaxis={"visible": False, "range": [-0.20, 1.05], "fixedrange": True},
showlegend=False,
)
# Save — canvas: 3200 × 1800 (landscape)
fig.write_image(f"plot-{THEME}.png", width=800, height=450, scale=4)
fig.write_html(f"plot-{THEME}.html", include_plotlyjs="cdn")
Part of Feynman Diagram for Particle Interactions on anyplot.ai.