TY  - JOUR
AU  - Li, Cheng
AU  - Moortgat-Pick, Gudrid
TI  - Determination of <i>C</i><i>P</i>-violating HZZ interaction with polarised beams at the ILC
JO  - The European physical journal / C
VL  - 85
IS  - 1
SN  - 1434-6044
CY  - Heidelberg
PB  - Springer
M1  - PUBDB-2026-00383
SP  - 99
PY  - 2025
AB  - We study possible <i>C</i><i>P</i>-violation effects of the 125 GeV Higgs to Z boson coupling at the 250 GeV ILC with transverse and longitudinal beam polarisation via the process e<sup>+</sup> e<sup>−</sup> → HZ → H μ<sup>−</sup>μ<sup>+</sup>. We explore the azimuthal angular distribution of the muon pair from the Z boson decay, and constructe <i>C</i><i>P</i>-odd observables sensitive to <i>C</i><i>P</i>-violation effects, where we derived this observable both by analytical calculations and by Whizard simulations. Particularly, we can construct two <i>C</i><i>P</i>-odd observables with the help of transversely-polarised initial beams and improve the statistical significance of <i>C</i><i>P</i>-violation effects by combining two measurements. We defined the asymmetries between the signal regions with different signs of the <i>C</i><i>P</i>-odd observables, and determine the <i>C</i><i>P</i>-violation effect by comparing with the SM 95
LB  - PUB:(DE-HGF)16
DO  - DOI:10.1140/epjc/s10052-025-13828-4
UR  - https://bib-pubdb1.desy.de/record/644524
ER  -