Preprint

PUBDB-2025-01355

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Determination of the first-generation quark couplings at the Z-pole

Mekala, K. (Corresponding author)DESY* ; Jeans, D. ; Reuter, J.DESY* ; Tian, J. ; Żarnecki, A. F.

2025

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Please use a persistent id in citations: doi:10.3204/PUBDB-2025-01355

Report No.: DESY-25-063; arXiv:2504.11365

Abstract: 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 constrained from LEP data to a few percent, 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. In this paper, we present a 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. The measurement could improve the LEP results by at least an order of magnitude.

Note: 22 pages, 8 figures

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Contributing Institute(s):

1. Theorie-Gruppe (T)

Research Program(s):

1. 611 - Fundamental Particles and Forces (POF4-611) (POF4-611)
2. EAJADE - Europe-America-Japan Accelerator Development and Exchange Programme (101086276) (101086276)
3. DFG project G:(GEPRIS)390833306 - EXC 2121: Quantum Universe (390833306) (390833306)

Experiment(s):

1. No specific instrument

Appears in the scientific report 2025

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Database coverage:
; ; Published

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Linked articles:

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Journal Article Mękała, K. (Corresponding author)DESY* ; Jeans, D. ; Reuter, J.DESY* ; Tian, J.Extern* ; Żarnecki, A. F.
Determination of the first-generation quark couplings at the Z-pole
Journal of high energy physics 11(11), 050 (2025) [10.1007/JHEP11(2025)050]2025     Files  Fulltext by arXiv.org BibTeX | EndNote: XML, Text | RIS

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