# Collimation of the e^+e^- annihilation event

Source: [Collimation of the e^+e^- annihilation event](<https://www.sota2.com/research/paper/68fa343d1e209131ce8972ad>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-24T20:32:22.295Z

Authors: K. Kimura, K. Tesima

Published: 1997-05-06T08:13:54.000Z

## Abstract

The collimation $C$ of a hadronic event in the e^+e^- annihilation is defined as the average of $\\cos\\theta$, $C=\<\\cos\\theta\>$, where $\\theta$ is the angle of each hadron measured from the thrust axis, and the average is over all the hadrons produced in an event. It is an infrared-stable event-shape parameter. $1-\\bar C$, the difference between the unity and the average collimation at a given energy, is proportional to the anomalous dimension of the hadron multiplicity at the leading order in MLLA. Its next-to-leading order corrections are calculated.

## Recorded benchmark results

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## Original sources and implementation

[Original paper](<https://arxiv.org/abs/hep-ph/9705238>)

[PDF](<https://arxiv.org/pdf/hep-ph/9705238.pdf>)