Searching for a New Source(s) of T-Violation in Spin Dependent Total Cross Section Measurements

TL;DR

This paper proves within the Standard Model that T-odd/P-odd total cross sections vanish for spin-1/2 particles, then explores potential Higgs sector contributions that could produce measurable effects under certain experimental conditions.

Contribution

It provides a complete proof that the Standard Model predicts zero T-odd/P-odd total cross sections and investigates possible Higgs sector effects that could lead to observable T-violation signals.

Findings

Standard Model predicts zero T-odd/P-odd total cross sections for spin-1/2 particles.

Higgs sector contributions can produce measurable T-odd/P-odd effects at tree level.

Measurable effects are possible if the Higgs mass is around 200 GeV and experimental conditions are optimized.

Abstract

We first re-prove with a more complete method that the the minimum standard model, with the inclusion of the CKM-matrix, requires the T-odd/P-odd total cross section of two spin-1/2 particles to vanish in all orders\cite{gxu}. Then we study the contribution to T-odd/P-odd total scattering cross sections from various channels within the Higgs sector, and optimize conditions for possible experimental measurements of these effects. These studies show that such contributions can appear at tree level, and that the spin dependent cross section asymmetry is measurable if the lightest Higgs paarticle is not too massive, {\it e.g.} $m_H \sim 200 GeV$, and if suitable reaction channels and beam energies and luminosities are chosen.