Exploring $HVV$ amplitudes with $CP$ violation by decomposition and on-shell scattering amplitude methods
In: Chinese Physics C Vol 47, No. 3(2023)033106; (2021)
Online
report
$CP$ violation may play an important role in Baryogenesis in early universe, and should be examined at colliders comprehensively. We study $CP$ properties of $HVV$ vertexes between Higgs and gauge boson pairs with defining a $CP$ violation phase angle $\xi$, which indicates the mixture of $CP$-even and $CP$-odd Higgs states in $HVV$ in new physics. A series of $HVV$ amplitudes $H\to\gamma\gamma, H\to\gamma V\to \gamma \ell\ell$, and $H\to VV\to 4\ell$ with $CP$ phase angle are studied systematically, which explains explicitly why $CP$ violation could only be probed in $4\ell$ process independently. We get a novel amplitude decomposition relation which illustrates if two preconditions (multilinear momentum dependent vertexes and current $J_\mu$ of $V\to \ell^+ \ell^-$ is formally proportional to a photon's polarization vector) are satisfied, an high-point amplitude can be decomposed into a summation of a series of low-point amplitudes. As a practical example, the amplitude of $H\to\gamma V\to \gamma \ell\ell$, and $H\to VV\to 4\ell$ processes can be decomposed into summation of many $H\to\gamma\gamma$ amplitudes. Meanwhile, we calculate these amplitudes in the framework of on-shell scattering amplitude method, with considering both massless and massive vector gauge bosons with $CP$ violation phase angle. The above two approaches provides consistent results and exhibit clearly the $CP$ violation $\xi$ dependence in the amplitudes.
Comment: 33 pages, 11 figures
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Exploring $HVV$ amplitudes with $CP$ violation by decomposition and on-shell scattering amplitude methods
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Autor/in / Beteiligte Person: | Feng, Ke-Yao ; Wan, Xia ; Wang, You-Kai ; Wu, Chao |
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Quelle: | Chinese Physics C Vol 47, No. 3(2023)033106; (2021) |
Veröffentlichung: | 2021 |
Medientyp: | report |
DOI: | 10.1088/1674-1137/aca8f5 |
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