Search for Colour Reconnection Effects in e+e- -> W+W- -> hadrons through Particle-Flow Studies at LEP

TL;DR

This study investigates the presence of colour reconnection effects in W boson decays at LEP by analyzing particle flow between jets, comparing data to models, and ruling out some reconnection scenarios.

Contribution

It provides the first detailed particle-flow analysis of colour reconnection effects in W pair decays at LEP energies, testing and constraining hadronisation models.

Findings

Extreme colour reconnection scenarios are ruled out.

Particle flow ratios are sensitive to reconnection effects.

Data favor models without strong reconnection effects.

Abstract

A search for colour reconnection effects in hadronic decays of W pairs is performed with the L3 detector at centre-of-mass energies between 189 and 209 GeV. The analysis is based on the study of the particle flow between jets associated to the same W boson and between two different W bosons in qqqq events. The ratio of particle yields in the different interjet regions is found to be sensitive to colour reconnection effects implemented in some hadronisation models. The data are compared to different models with and without such effects. An extreme scenario of colour reconnection is ruled out.