Prospects for direct CP tests of $hqq$ interactions

TL;DR

This paper explores the potential for measuring CP violation in Higgs-quark interactions through baryon decays, concluding that only a high-luminosity muon collider can feasibly detect such effects.

Contribution

It assesses the feasibility of probing CP structure in $hqq$ interactions via baryon decay distributions at future colliders, highlighting the unique potential of muon colliders.

Findings

High-luminosity $e^+ e^-$ colliders are unlikely to perform these tests.

High-luminosity $^+^-$ colliders can measure CP-sensitive distributions.

Only $^+^-$ colliders can produce enough events to probe CP asymmetry in $hbb$ vertex.

Abstract

We study the prospects for probing the CP structure of $hqq$ interactions using the decays of the lightest baryon $\Lambda_q$ formed in the quark's hadronization. The low yields of reconstructible events make it unlikely for tests to be performed with the next generation of colliders. In $h\to b\bar b\to \Lambda_b \bar\Lambda_b$ decays a CP-sensitive distribution could be measured with a high-luminosity $e^+ e^-$ collider, while in both $h\to b\bar b\to \Lambda_b \bar\Lambda_b$ and $h\to c\bar c\to \Lambda_c \bar\Lambda_c$ decays such a distribution could be measured with a very high luminosity $\mu^+ \mu^-$ collider. However, we find that only the $\mu^+ \mu^-$ collider can produce enough $h\to b\bar b\to \Lambda_b \bar\Lambda_b$ decays to probe a physical CP asymmetry in the $hbb$ vertex.