Next-to-Leading-Order Corrections to the Production of Heavy-Flavour Jets in e+e- Collisions

TL;DR

This thesis delivers a complete next-to-leading-order calculation of heavy-flavour jet production in $e^+e^-$ annihilation, incorporating full quark-mass effects and addressing infrared and ultraviolet divergences with a subtraction method. It develops both fixed-order and resummed fragmentation-function formalisms, derives phase-space and amplitude structures for all relevant final states, and provides an explicit, Fortran-implemented tool to predict heavy-quark momentum correlations and jet observables across energy scales. The work confirms small mass-corrections to key observables, enables consistent extraction of $\alpha_s$ and fragmentation properties, and offers a robust framework for future high-energy colliders where heavy-quark effects are essential. Overall, it bridges fixed-order QCD and resummation in the heavy-quark sector, delivering analytic results, numerical validations, and practical computational resources for precision jet phenomenology.

Abstract

In this thesis we describe the calculation of the process e+ e- --> Z/gamma -> Q Qbar + X, where Q is a heavy quark, X is anything else at order alpha_s^2.

Figures (35)

• Figure 1: Double inclusive cross section $d \sigma/dx_1\,dx_2$, plotted as a function of $x_1$ for several values of $x_2$.
• Figure 2: $C_FC_A$ component of the ${}\alpha_s$α̅_s$^2$ coefficient in $\sigma(N,E,m)$, as a function of $\log E^2/m^2$, for $N=$2, 5, 8 and 11. The dashed lines correspond to the alternative approach proposed by the authors of Ref. Spira.
• Figure 3: Same as in Fig. \ref{['fig:ca']}, for the $n_f C_F T_F$ component.
• Figure 4: Same as in Fig. \ref{['fig:ca']}, for the $C_F^2$ component.
• Figure 5: Same as in Fig. \ref{['fig:ca']}, for the $C_F T_F$ component.