Exploring CP phase in $\tau$-lepton Yukawa coupling in Higgs decays at the LHC

Abstract

We study the prospect of determining the CP violating phase in $\tau$-lepton Yukawa coupling at the Large Hadron Collider (LHC). While the current run is already exploring the production of a pair of the third generation $\tau$ leptons from Higgs decay, these measurements are not sensitive enough to constrain the CP violating phase. In this paper, several CP odd observables are proposed and analyzed utilizing the dominant channels with the semi-invisible hadronic decay of $\tau$. Several asymmetries corresponding to the T odd momentum correlations are also studied and their sensitivities to the CP violating phase in tau-lepton Yukawa couplings are estimated at 13 TeV LHC with 1000 ${fb}^{-1}$ of integrated luminosity. We also present a novel way to reconstruct $\tau$ momentum at the LHC utilizing the information of impact parameter. Finally, we obtain that the asymmetries can be as large as 35$\%$ for a case of maximal CP violation in the $\tau$ Yukawa couplings.

8 pages, 3 figures, 1 table. V3: Some clarifications added; version to appear in Journal of Physics G: Nuclear and Particle Physics

References in corpus (14)

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector
• Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton-proton collisions at the LHC
• Determining the CP parity of Higgs bosons at the LHC in their tau decay channels
• Constraining CP-violating Higgs Sectors at the LHC using gluon fusion
• Determining the CP parity of Higgs bosons at the LHC in the $\tau$ to 1-prong decay channels
• Determination of the Higgs CP mixing angle in the tau decay channels at the LHC including the Drell-Yan background
• Probing CP violation in $h\to {\tau }^{-}{\tau }^{+}$ at the LHC
• Prospect for measuring the CP phase in the $h\tau \tau$ coupling at the LHC
• Reconstructing semi-invisible events in resonant tau pair production from Higgs
• Measuring the CP property of Higgs coupling to tau leptons in the VBF channel at the LHC
• Constrained $\sqrt{{\hat{S}}_{min}}$ and reconstructing with semi-invisible production at hadron colliders

Cited by in corpus (3)

• CP-violating Higgs Di-tau Decays: Baryogenesis and Higgs Factories
• Testing CP Properties of Extra Higgs States at the HL-LHC
• Measuring $CP$ nature of $h\tau \bar{\tau }$ coupling at $e^{-}p$ collider