New Observables for CP Violation in Higgs Decays

Abstract

Current experimental data on the 125 GeV Higgs boson still allow room for large CP violation. The observables usually considered in this context are triple product asymmetries, which require an input of four visible particles after imposing momentum conservation. We point out a new class of CP violating observables in Higgs physics which require only three reconstructed momenta. They may arise if the process involves an interference of amplitudes with different intermediate particles, which provide distinct strong phases in the form of the Breit-Wigner widths, in addition to possible weak phases that arise from CP violating couplings of the Higgs in the Lagrangian. As an example, we propose a forward-backward asymmetry of the charged lepton in the three-body Higgs decay, $h\to {\ell }^{-}{\ell }^{+}\gamma$, as a probe for CP-violating Higgs couplings to $Z\gamma$ and $\gamma \gamma$ pairs. Other processes exhibiting this type of CP-violation are also discussed.

11 pages; v2: minor corrections, references added

References in corpus (10)

• 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
• Anomalous Higgs boson couplings in vector boson fusion at the CERN LHC
• Aspects of CP violation in the HZZ coupling at the LHC
• Determining the CP parity of Higgs bosons at the LHC in the $\tau$ to 1-prong decay channels
• Landau-Yang Theorem and Decays of a Z' Boson into Two Z Bosons
• Measuring spin and CP from semi-hadronic ZZ decays using jet substructure
• Probing the Higgs Couplings to Photons in $h\to 4\ell$ at the LHC
• CP-violating HWW couplings at the Large Hadron Collider
• Distinguishing `Higgs' Spin Hypotheses using gamma gamma and WW* Decays

Cited by in corpus (8)

• Exploring the Anomalous Higgs-top Couplings
• Aligned CP-violating Higgs sector canceling the electric dipole moment
• Jet substructure and probes of CP violation in Vh production
• Angular distribution and forward-backward asymmetry of the Higgs-boson decay to photon and lepton pair
• $H\to {\tau }^{+}{\tau }^{-}\gamma$ as a Probe of the $\tau$ Magnetic Dipole Moment
• Exploring anomalous $HZ\gamma$ couplings in $\gamma$-proton collisions at the LHC
• A Simple Model of Dark Matter and CP Violation
• Determination of the Higgs CP-mixing angle in the tau decay channels