Speaker
Description
In this talk, I will cover both the Axion-Like Particles and Tau weak electric dipole moments. Our combined analysis shows that mono-V and non-resonant VBS channels provide powerful and complementary probes of ALP-gauge boson interactions. Tau spin correlations at the Z pole probe CP violation with a sensitivity that depends strongly on the spin projection. For a fixed Z sample, transverse moments avoid the chirality suppression of longitudinal and triple-product observables, enhancing the response by a factor $m_Z/2m_\tau=26$. Two transverse moments also select the axial tau charge, gaining $|a_\tau/v_\tau|=13.5$; the sign-weighted normal moment has a response 521 times that of the triple product. These two transverse moments give single-parameter uncertainties no more than 14% above our calculated Cramer-Rao bound for independent single-pion measurements, approaching the best precision within this analysis. A five-moment fit with 5% off-peak luminosity yields statistical uncertainties of $4.5(5.5)\times10^{-7}$ and $2.7(3.2)\times10^{-6}$ on Re$\tilde{d}d^W_\tau$ and Im$\tilde{d}^W_\tau$, respectively, at FCC-ee (CEPC), improving on ALEPH by three orders of magnitude. The electromagnetic-dipole uncertainty is $9.6(12)\times10^{−6}$ on Re$\tilde{d}^\gamma_\tau$, two orders beyond Belle. These projections assume ideal angular reconstruction and constant form factors across the scan.
