English

Bottom quark forward-backward asymmetry at the future electron-positron collider FCC-ee

High Energy Physics - Phenomenology 2025-02-05 v2 High Energy Physics - Experiment

Abstract

The Standard Model (SM) prediction for the \PZ-boson pole bb-quark forward-backward (FB) asymmetry is: (AFB0,b)th=0.1030±0.0002(A_{FB}^{0,b})_{th} = 0.1030 \pm 0.0002. The LEP electron-positron collider measured instead AFB0,b=0.0992±0.0016A_{FB}^{0,b} = 0.0992 \pm 0.0016, value which presents the largest discrepancy with any of the SM predictions as of today. All the AFBbA_{FB}^b measurements performed at LEP suffered however of an important statistical uncertainty and of different sources of systematic uncertainties. This study shows that the proposed high-luminosity electron-positron collider FCC-ee, collecting orders of magnitude more data at the \PZ-pole than LEP, will significantly reduce the statistical uncertainties on the measurement of AFB0,bA_{FB}^{0,b}, thus allowing us to shed further light on this tension.

Keywords

Cite

@article{arxiv.2501.17677,
  title  = {Bottom quark forward-backward asymmetry at the future electron-positron collider FCC-ee},
  author = {Marina Cobal and Giovanni Guerrieri and Hamzeh Khanpour and Giancarlo Panizzo and Michele Pinamonti and Laura Pintucci and Leonardo Toffolin},
  journal= {arXiv preprint arXiv:2501.17677},
  year   = {2025}
}