Effects of the anomalous Higgs couplings on the Higgs boson production at the Large Hadron Collider

TL;DR

This work investigates how TeV-scale new physics, encoded as dimension-six operators, alters Higgs production in gluon fusion at the LHC. Using an effective Lagrangian, it focuses on operators that modify the top-Yukawa coupling ($a_{t1}$) and Higgs self-interactions ($a_{Φ1}$, $a_{Φ2}$) as well as the tree-level $ggH$ interaction from $O_G$, with the top Yukawa expressed as $y_t^{eff}=Z_{Φ1}( rac{ ext{sqrt}(2) m_t}{v} - a_{t1})$ where $Z_{Φ1}=(1+a_{Φ1})^{-1/2}$. Numerical results show that the single-Higgs production cross section can be significantly enhanced or suppressed (up to factors of $9/4$ or $1/4$) by $a_{t1}$ and $a_G$, while double-Higgs production can be strongly boosted by the same operators through $tar t HH$ and modified top-Yukawa effects; $a_{Φ2}$ can further modify the triple-Higgs coupling, potentially amplifying the $gg o HH$ rate by up to ~$(140 ext{%)$ for certain masses. The study demonstrates that combining $gg o H$ and $gg o HH$ provides a way to disentangle $O_{t1}$ and $O_G$ contributions and constrain TeV-scale new physics in the top-Higgs sector, with implications for future colliders.

Abstract

We study the impact of dimension-six operators on single- and double-Higgs production rates via gluon fusion at the Large Hadron Collider (LHC). If the top-Yukawa coupling is modified by some new physics whose scale is of the TeV scale, its effect changes the cross sections of single-Higgs production $gg\to H$ and double-Higgs production $gg\to HH$ through the top-loop diagram. In particular, double-Higgs production can receive significant enhancement from the effective top-Yukawa coupling and the new dimension-five coupling $t{\bar t}HH$ which are induced by the dimension-six operator. Comparing these results to the forthcoming data at the LHC, one can extract information of the dimension-six operators relevant to the top quark and the Higgs boson.

Figures (13)

• Figure 1: Feynman diagrams for the single-Higgs production process via gluon fusion. Curled, dashed and solid lines represent gluons, Higgs bosons and quarks, respectively. Dots denote the new physics interaction. In the SM, there is no tree level contact interaction.
• Figure 2: The cross section of $pp\to ggX\to HX$ with $\sqrt{s}=14$ TeV as a function of the Higgs boson mass. Curves denote the cross sections derived in the SM (Set A), and in the SM with anomalous dimension-six couplings (Set B--Set E).
• Figure 3: The plot of the statistical sensitivity for $a_{t1}^{}$ on $N=L\sigma(pp\to ggX\to HX){\mathcal{B}}(H\to WW, \gamma\gamma)$ where the integrated luminosity is $L=300 \text{fb}^{-1}$. Each curve denotes the $1\sigma$ deviation from the SM predictions.
• Figure 4: The plot of the statistical sensitivity for $a_G^{}$ on $N=L\,\sigma(pp\to ggX\to HX){\mathcal{B}}(H\to WW, \gamma\gamma)$ where the integrated luminosity is $L=300 \text{fb}^{-1}$. Each curve denotes the $1\sigma$ deviation from the SM predictions.
• Figure 5: The sensitivity plots in the $a_{t1}^{}$--$a_G^{}$ plane on $N=L\,\sigma(pp\to ggX\to HX){\mathcal{B}}(H\to WW, \gamma\gamma)$ where the integrated luminosity is $L=300 \text{fb}^{-1}$. Each contour represents the $1\sigma$ deviation from the SM predictions.