First Measurement of the T-odd Correlation between the Z0 Spin and the Three-jet Plane Orientation in Polarized Z0 Decays to Three Jets

TL;DR

This paper reports the first measurement of a T-odd correlation between the Z0 spin and the three-jet plane in polarized Z0 decays, testing for new physics beyond the Standard Model.

Contribution

It introduces the first experimental measurement of a CP-even, T-odd triple product in polarized Z0 decays to three jets, setting limits on possible new physics effects.

Findings

Measured the T-odd correlation to be consistent with zero.

Set 95% confidence level limits on the correlation parameter.

Provided constraints on physics beyond the Standard Model.

Abstract

We present the first measurement of the correlation between the $Z^0$ spin and the three-jet plane orientation in polarized $Z^0$ decays into three jets in the SLD experiment at SLAC utilizing a longitudinally polarized electron beam. The CP-even and T-odd triple product $\vec{S_Z}\cdot(\vec{k_1}\times \vec{k_2})$ formed from the two fastest jet momenta, $\vec{k_1}$ and $\vec{k_2}$, and the $Z^0$ polarization vector $\vec{S_Z}$, is sensitive to physics beyond the Standard Model. We measure the expectation value of this quantity to be consistent with zero and set 95\% C.L. limits of $-0.022 < \beta < 0.039$ on the correlation between the $Z^0$-spin and the three-jet plane orientation.