Do the quark masses run? Extracting $m_b(m_Z)$ from LEP data

Abstract

We present the first results of next-to-leading order QCD corrections to three jet heavy quark production at LEP including mass effects. Among other applications, this calculation can be used to extract the bottom quark mass from LEP data, and therefore to test the running of masses as predicted by QCD.

Figures (2)

• Figure 1: NLO results for $R_3^{bd}$ for $\mu=m_Z$ (dashed), $\mu=30~GeV$ (dashed-dotted) and $\mu= 10~GeV$ (dotted) for $\bar{m}_b(m_Z)= 3~GeV$ and $\alpha_s(m_Z)=0.118$. For comparison we also plot the LO results for $M_b = 5~GeV$ (lower solid line) and $\bar{m}_b(m_Z) = 3~GeV$ (upper solid line)
• Figure 2: Extracted value of $\bar{m}_b(m_Z)$ if $R^{bd}_{3\, exp}=0.96$ as a function of the scale $\mu$. We take $\alpha_s(m_Z)=0.118$ (solid) and $\Delta \alpha_s = 0.003$ (dashed).