6–11 Jul 2025
PALAIS DU PHARO, Marseille, France
Europe/Paris timezone

Determination of the first-generation quark couplings at the Z-pole

10 Jul 2025, 10:10
20m
PALAIS DU PHARO, Marseille, France

PALAIS DU PHARO, Marseille, France

Parallel T06 - Top and Electroweak Physics Joint T06+T08

Speaker

Krzysztof Mekala (University of Warsaw / DESY)

Description

Electroweak Precision Measurements are stringent tests of the Standard Model and sensitive probes to New Physics. Accurate studies of the Z-boson couplings to the first-generation quarks, which are currently only constrained from LEP data, could reveal potential discrepancies from the theory predictions. Future $e^+e^-$ colliders running at the $Z$-pole would be an excellent tool for an analysis based on a comparison of radiative and non-radiative $Z$ boson decays.

We present the corresponding method to extract the values of the $Z$ couplings to light quarks and discuss the uncertainty of the measurement, including contributions from various systematic effects. We show that systematic uncertainty in the heavy-flavour tagging performance is the key factor in the analysis and reducing it to a sub-permille level might be crucial to fully profit from the high luminosity of future $e^+e^-$ machines. In such a case, the measurement could improve the LEP results by at least an order of magnitude.

Secondary track T07 - Flavour Physics and CP Violation

Authors

Prof. Aleksander Filip Zarnecki (University of Warsaw) Daniel Jeans (KEK / IPNS) Junping Tian (University of Tokyo) Jürgen Reuter (DESY Hamburg, Germany) Krzysztof Mekala (University of Warsaw / DESY)

Presentation materials

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