ScienceSeptember 1, 2026

sigma

SIG-muh

Definition

A statistical unit of measure representing standard deviation, used in particle physics to denote the degree of confidence or significance of a scientific result.

Etymology

Derived from the Greek alphabet, where it is the name of the 18th letter. In statistics and science, the lowercase sigma (σ) is the standard symbol used to represent the standard deviation of a population.

In the news

In this article, 'sigma' describes the level of statistical confidence for the LZ experiment's detection. A 2.6 sigma significance means there is a notable, though not yet conclusive, chance that the observation could be due to background noise rather than dark matter.

New Detection In Dark Matter Experiment Has Physicists Excited – Is It An Unexpected And Rare Background Or The First Evidence Of Dark Matter?

Read the full article ↗

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