The second order QCD contribution to the semileptonic b -> u decay rate

Abstract

The order alpha_s^2 contribution to the inclusive semileptonic decay width of a b quark Γ(b -> X_u e \barν_e) is calculated analytically for zero mass u quarks.

Figures (2)

• Figure 1: Examples of non-abelian diagrams whose cuts give contributions to $b \rightarrow u e \overline{\nu}_e$, $b \rightarrow u e \overline{\nu}_e g$, $b \rightarrow u e \overline{\nu}_e g g$.
• Figure 2: Renormalization scale dependence of $\Gamma( b \rightarrow X_u e \overline{\nu}_e )$ near $\mu = m_b(m_b)$ in different orders of perturbative QCD for $\alpha_s^{(5)}(m_Z) = 0.118$, $m_b^{(5)}(m_b) = {\rm 4.3\; GeV}$ and $|V_{ub}| = 0.003$ .