Energy and angular distributions of the bottom quark in the electron-positron annihilation $e^+e^-\to b \, W^+ \, \bar{t}$

Abstract

The distributions of the bottom quark in the process $e^+ e^- \to t \, \bar{t} \to b \, W^+ \, \bar{t}$ are considered at the $e^+ e^-$ energy corresponding to the first construction stage of the Compact Linear Collider. The cross sections of $e^+ e^- \to b \ldots$, as functions of the $b$-quark energy and angle with respect to the direction of the electron beam, are derived and calculated. The effects of physics beyond the Standard Model are included via the modified $\gamma t \bar{t}$ and $Z t \bar{t}$ couplings which naturally appear in effective field theories. In addition to the cross sections, the energy and angular asymmetries are calculated. The dependence of these observables on the $e^+ e^-$ energy is calculated, and features of this dependence are investigated.