Speaker
Description
Global fits to electroweak precision data, comparing the measured values of different quantities with the SM predictions, provide important checks of the SM consistency and sensitivity to beyond-the-SM (BSM) effects. The two most sensitive determinations of $\sin^2 \theta_{\rm eff}^{\rm lep}$, from the LEP measurement of $A_{0,b}^{FB}$ and the SLD measurement of $A_\ell$,
are in $\sim$3 $\sigma$ tension with each other, the largest deviation in global electroweak fits.
In this contribution we discuss the possibility to probe at the FCC-ee the interactions between the $Z$ boson and the bottom quark through a competitive determination of $A_{0,b}^{FB}$.
To this extent we aim to reproduce the measurement performed at LEP, exploiting the decay of a $Z$ boson in a bottom-quarks pair.
The definition of this asymmetry intrinsically requires some sensitivity to the charge of the bottom quark/antiquark in the final state, which represents one of the major challenges of this measurement. By means of a simplified Delphes-based simulation tuned to the IDEA detector at FCC, we plan to study the expected experimental b-jet charge identification performances using either constituent tracks information or exploiting the charge of a soft muon from $B$-hadron decays.
