Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Charged particle multiplicity in three-jet events and two-gluon systems
AU - DELPHI Collaboration, The
AU - Borissov, Guennadi V.
AU - Sopczak, A.
N1 - Author list is partial - see original article for full author list.
PY - 2005/10
Y1 - 2005/10
N2 - The charged particle multiplicity in hadronic three-jet events from Z decays is investigated. The topology dependence of the event multiplicity is found to be well described by a modified leading logarithmic prediction. A parameter fit of the prediction to the data yields a measurement of the colour factor ratio CA/CF with the result CA/CF = 2.261 ± 0.014stat. ± 0.036exp. ± 0.066theo. in agreement with the SU(3) expectation of QCD. The quark-related contribution to the event multiplicity is subtracted from the three-jet event multiplicity resulting in a measurement of the multiplicity of twogluon colour-singlet states over a wide energy range. The ratios r = Ngg(s)/Nq¯q(s) of the gluon and quark multiplicities and r(1) = N gg(s)/Nq ¯q(s) of their derivatives are compared with perturbative calculations. While a good agreement between calculations and data is observed for r(1), larger deviations are found for r indicating that non-perturbative effects are more important for r than for r(1).
AB - The charged particle multiplicity in hadronic three-jet events from Z decays is investigated. The topology dependence of the event multiplicity is found to be well described by a modified leading logarithmic prediction. A parameter fit of the prediction to the data yields a measurement of the colour factor ratio CA/CF with the result CA/CF = 2.261 ± 0.014stat. ± 0.036exp. ± 0.066theo. in agreement with the SU(3) expectation of QCD. The quark-related contribution to the event multiplicity is subtracted from the three-jet event multiplicity resulting in a measurement of the multiplicity of twogluon colour-singlet states over a wide energy range. The ratios r = Ngg(s)/Nq¯q(s) of the gluon and quark multiplicities and r(1) = N gg(s)/Nq ¯q(s) of their derivatives are compared with perturbative calculations. While a good agreement between calculations and data is observed for r(1), larger deviations are found for r indicating that non-perturbative effects are more important for r than for r(1).
U2 - 10.1140/epjc/s2005-02390-x
DO - 10.1140/epjc/s2005-02390-x
M3 - Journal article
VL - 44
SP - 311
EP - 331
JO - European Physical Journal C: Particles and Fields
JF - European Physical Journal C: Particles and Fields
SN - 1434-6044
IS - 3
ER -