TY - JOUR

T1 - Production of K0S and Λ in quark and gluon jets from Z0 decay

AU - Kartvelishvili, Vakhtang

AU - OPAL Collaboration

PY - 1999/4

Y1 - 1999/4

N2 - The production of K0SKS0 mesons and ΛΛ baryons in quark and gluon jets has been investigated using two complementary techniques. In the first approach, which provides high statistical accuracy, jets were selected using different jet finding algorithms and ordered according to their energy. Production rates were determined taking into account the dependences of quark and gluon compositions as a function of jet energy as predicted by Monte Carlo models. Selecting three-jet events with the k⊥k⊥ (Durham) jet finder ( ycut=0.005ycut=0.005 ), the ratios of K0SKS0 and ΛΛ production rates in gluon and quark jets relative to the mean charged particle multiplicity were found to be 1.10±0.02±0.021.10±0.02±0.02 and 1.41±0.04±0.041.41±0.04±0.04 , respectively, where the first uncertainty is statistical and the second is systematic. In the second approach, a new method of identifying quark jets based on the collimation of energy flow around the jet axis is introduced and was used to anti-tag gluon jets in symmetric (Y-shaped) three-jet events. Using the cone jet finding algorithm with a cone size of 30°, the ratios of relative production rates in gluon and quark jets were determined to be 0.94±0.07±0.070.94±0.07±0.07 for K0SKS0 and 1.18±0.10±0.171.18±0.10±0.17 for ΛΛ . The results of both analyses are compared to the predictions of Monte Carlo models.

AB - The production of K0SKS0 mesons and ΛΛ baryons in quark and gluon jets has been investigated using two complementary techniques. In the first approach, which provides high statistical accuracy, jets were selected using different jet finding algorithms and ordered according to their energy. Production rates were determined taking into account the dependences of quark and gluon compositions as a function of jet energy as predicted by Monte Carlo models. Selecting three-jet events with the k⊥k⊥ (Durham) jet finder ( ycut=0.005ycut=0.005 ), the ratios of K0SKS0 and ΛΛ production rates in gluon and quark jets relative to the mean charged particle multiplicity were found to be 1.10±0.02±0.021.10±0.02±0.02 and 1.41±0.04±0.041.41±0.04±0.04 , respectively, where the first uncertainty is statistical and the second is systematic. In the second approach, a new method of identifying quark jets based on the collimation of energy flow around the jet axis is introduced and was used to anti-tag gluon jets in symmetric (Y-shaped) three-jet events. Using the cone jet finding algorithm with a cone size of 30°, the ratios of relative production rates in gluon and quark jets were determined to be 0.94±0.07±0.070.94±0.07±0.07 for K0SKS0 and 1.18±0.10±0.171.18±0.10±0.17 for ΛΛ . The results of both analyses are compared to the predictions of Monte Carlo models.

U2 - 10.1007/s100529901058

DO - 10.1007/s100529901058

M3 - Journal article

VL - 8

SP - 241

EP - 254

JO - European Physical Journal C: Particles and Fields

JF - European Physical Journal C: Particles and Fields

SN - 1434-6044

IS - 2

ER -