Testing Higgs models via the H±W∓ZH^\pm W^\mp Z vertex by a recoil method at the International Linear Collider

In general, charged Higgs bosons $H^\pm$ appear in non-minimal Higgs models. The $H^\pm W^\mp Z$ vertex is known to be related to the violation of the global symmetry (custodial symmetry) in the Higgs sector. Its magnitude strongly depends on the structure of the exotic Higgs models which contain higher isospin $SU(2)_L$ representations such as triplet Higgs bosons. We study the possibility of measuring the $H^\pm W^\mp Z$ vertex via single charged Higgs boson production associated with the $W^\pm$ boson at the International Linear Collider (ILC) by using the recoil method. The feasibility of the signal $e^+e^-\to H^\pm W^\mp \to \ell \nu jj$ is analyzed assuming the polarized electron and positron beams and the expected detector performance for the resolution of the two-jet system at the ILC. The background events can be reduced to a considerable extent by imposing the kinematic cuts even if we take into account the initial state radiation. For a relatively light charged Higgs boson whose mass $m_{H^\pm}$ is in the region of 120-130 GeV $< m_{H^\pm} < m_W+m_Z$, the $H^\pm W^\mp Z$ vertex would be precisely testable especially when the decay of $H^\pm$ is lepton specific. The exoticness of the extended Higgs sector can be explored by using combined information for this vertex and the rho parameter.Comment: 22 pages, 23 figure

Vector Boson Pair Production in Hadronic Collisions at Order αs\alpha_s: Lepton Correlations and Anomalous Couplings

We present cross sections for production of electroweak vector boson pairs, $WW$, $WZ$ and $ZZ$, in $p\bar{p}$ and $pp$ collisions, at next-to-leading order in $\alpha_s$. We treat the leptonic decays of the bosons in the narrow-width approximation, but retain all spin information via decay angle correlations. We also include the effects of $WWZ$ and $WW\gamma$ anomalous couplings.Comment: 23 pages, 8 figures, 3 table