% miko:type: atomic
% miko:title: Cross Section and Luminosity
% miko:summary: The basic language for event rates in scattering experiments.
% miko:tags: particle
% miko:difficulty: undergrad
% miko:related: feynman-diagrams, standard-model, complete-particle-physics
% miko:keywords: scattering, detector, event rate

\documentclass{article}
\usepackage{amsmath}
\title{Cross Section and Luminosity}
\begin{document}
\maketitle

\section{Cross Section}

A cross section $\sigma$ measures the effective probability for a scattering
process. It has units of area.

\section{Event Rate}

The event rate is

$$
R=\mathcal L\sigma,
$$

where $\mathcal L$ is the luminosity.

\section{Interpretation}

Theory predicts cross sections; experiments measure event rates. Luminosity is
the bridge between them.

\end{document}
