Potential for measuring the $H^{\pm }{W}^{\mp }{Z}^0$ vertex from $WZ$ fusion at the CERN Large Hadron Collider

We investigate the possibility of measuring the $H^{\pm }{W}^{\mp }{Z}^0$ vertex from the single $H^{\pm }$ production process via $WZ$ fusion at the CERN Large Hadron Collider (LHC). This vertex strongly depends on the structure of the Higgs sector in various new physics scenarios, so that its measurement can be useful to distinguish the models. A signal and background simulation under the expected detector performance at the LHC is done for the processes of $pp\to W^{\pm }{Z}^{0}X\to H^{\pm }X\to tbX$ and $pp\to W^{\pm }{Z}^{0}X\to H^{\pm }X\to W^{\pm }{Z}^{0}X$, and the required magnitudes of the $H^{\pm }{W}^{\mp }{Z}^0$ vertex for observation are evaluated. It is found that although the loop-induced $H^{\pm }{W}^{\pm }{Z}^0$ vertex in multi-Higgs doublet models cannot be measurable, the latter process can be useful to test the model with a real and a complex triplets.

Figure 1

The hadronic cross section of the $W^{\pm }{Z}^0$ fusion process and the $W^{+}{W}^{-}$ fusion process as a function of the mass of the charged and neutral Higgs bosons, respectively. For the $W^{\pm }{Z}^0$ fusion, the form factor $F$ is set to be unity. The SM prediction is shown for the $W^{+}{W}^{-}$ fusion.

Figure 2

The $P_T$ distribution for the $b$-jets with the highest $P_T$ from the signal ($pp\to W^{\pm }{Z}^{0}X\to H^{\pm }X\to tbX$ at $m_{H^{\pm }}=700\mathrm{GeV}$) and background (top pair production). The solid (dashed) histogram represents the signal (top pair production).

Figure 3

The distribution for the pseudorapidity $\eta$ of electrons from the signal ($pp\to W^{\pm }{Z}^{0}X\to H^{\pm }X\to W^{\pm }{Z}^{0}X\to jj\ell \nu X$ at $m_{H^{\pm }}=800\mathrm{GeV}$) and backgrounds (top pair production, $W+4j$). The solid (dotted) histogram represents the signal ($W+4j$).

Figure 4

The distribution for $\Delta R_{\max }$ from the signal ($pp\to W^{\pm }{Z}^{0}X\to H^{\pm }X\to W^{\pm }{Z}^{0}X\to jj\ell \nu X$ at $m_{H^{\pm }}=800\mathrm{GeV}$) and backgrounds (top pair production, $W+4j$). The solid (dashed, dotted) histogram represents the signal (top pair production, $W+4j$).

Figure 5

The distribution for $\Delta R_{\min }$ from the signal ($pp\to W^{\pm }{Z}^{0}X\to H^{\pm }X\to W^{\pm }{Z}^{0}X\to jj\ell \nu X$ at $m_{H^{\pm }}=800\mathrm{GeV}$) and backgrounds (top pair production, $W+4j$). The solid (dashed, dotted) histogram represents the signal (top pair production, $W+4j$).

Figure 6

The distribution for $\Delta R_{j_3{j}_4}$ from the signal ($pp\to W^{\pm }{Z}^{0}X\to H^{\pm }X\to W^{\pm }{Z}^{0}X\to jj\ell \nu X$ at $m_{H^{\pm }}=800\mathrm{GeV}$) and backgrounds (top pair production, $W+4j$). The solid (dashed, dotted) histogram represents the signal (top pair production, $W+4j$).