Three-jet final states inZ0decay for heavy quarks

We study the influence of quark masses on the values of average spherocity $S$ and average thrust $T$ for $Z^0$ boson decay into three jets in the standard model. We find that for quark masses ($m_q$) greater than ∼10 GeV the average values $〈S〉$ and $〈1-T〉$ may be significantly altered from their values for massless quarks previously obtained in the literature.