Introduction

The analysis of data and extraction of relevant results are goals of particle physics and astroparticle physics experiments. This involves the processing of raw detector data to yield a variety of final-state physics objects followed by the application of selection criteria designed to extract and study a signal process of interest while rejecting (or reducing to a known and manageable level) background processes which may mimic it. Collectively, this is referred to as an analysis. Physics analyses are performed either to measure a known physical quantity (e.g. the lifetime of an unstable particle), or to determine if the data are compatible with a physics hypothesis (e.g. the existence of a Higgs boson). At each stage, however, a variety of ‘higher-order’ issues separate particle physics and astroparticle physics analyses from a brute-force application of signal-processing techniques.

Reconstruction of raw detector data

All physics analysis starts from the information supplied from the dataacquisition system, the raw detector data.