Central-edge asymmetry as a probe of Higgs-top coupling in tt¯h production at the LHC

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

5 years ago

Central-edge asymmetry as a probe of Higgs-top coupling in tt¯h production at the LHC

The Higgs-top coupling plays a central role in the hierarchy problem and the vacuum stability of the Standard Model (SM). We propose a central-edge asymmetry (

A_{C E}

) to probe the CP violating Higgs-top coupling in dileptonic channel of

t \bar{t} h (\to b \bar{b})

production at the LHC. We demonstrate that the CP-violating Higgs-top coupling can affect the central-edge asymmetry through distorting

Δ y_{ℓ^{+} ℓ^{-}}

distribution because of the contribution of new top charge asymmetric term. Since

Δ y_{ℓ^{+} ℓ^{-}}

distribution is frame-independent and has a good discrimination even in boosted regime, we use the jet substructure technique to enhance the observability of the dileptonic channel of

t \bar{t} h

production. We find that (1) the significance of dileptonic channel of

t \bar{t} h

production can reach 5σ for CP phase

ξ = 0, π / 4, π / 2

when the luminosity

L = 795, 993, 1276 {fb}^{- 1}

at 14 TeV LHC. (2) the central-edge asymmetry

A_{C E}

show a good discrimination power of CP phase of

t \bar{t} h

interaction, which are

- 40.26 %

,

- 26.60 %

,

- 9.47 %

for

ξ = 0

,

π / 4

,

π / 2

respectively and are hardly affected by the event selections. Besides, by performing the binned-

χ^{2}

analysis of

Δ y_{ℓ^{+} ℓ^{-}}

distribution, we find that the scalar and pseudo-scalar interactions can be distinguished at 95% C.L. level at 14 TeV HL-LHC.

Publisher URL: www.sciencedirect.com/science

DOI: S0370269318301114