Higgs Production Processes Research Articles

Production of neutral MSSM Higgs bosons ine + e − collisions: a complete 1-loop calculation

We present the first complete 1-loop diagrammatic calculation of the cross sections for the neutral Higgs production processes $e^+e^-\ra Z^0h^0$ and $e^+e^-\ra A^0h^0$ in the minimal supersymmetric standard model. We compare the results from the diagrammatic calculation with the corresponding ones of the simpler and compact effective potential approximation and discuss the typical size of the differences.

Using rapidity gaps to distinguish between Higgs boson production by W and gluon fusion.

The possibility of distinguishing between two higgs production mechanisms, W fusion and gluon fusion, is investigated using the Monte Carlo event generator PYTHIA. It is shown that, considering the designed CM energy and luminosity for the LHC, it is not possible to distinguish between the two higgs production processes as, for a given integrated luminosity, they lead to the same number of events containing a rapidity gap.

Higgs production inSU(2) c symmetric interactions

We study the sensitivity of Higgs production and decay processes to theSU(2)c symmetric couplingsOW andOUW. Remarkable results are obtained in the case of γγ→H and for certain ratios of Higgs decay widths. We also discuss and complete previous results on unitarity constraints for such couplings.

Higgs production inSU(2) c symmetric interactions

We study the sensitivity of Higgs production and decay processes to the $SU(2)_c$ symmetric couplings $O_W$ and $O_{UW}$. Remarkable results are obtained in the case of $\gamma \gamma \to H$ and for certain ratios of Higgs decay widths. We also discuss and complete previous results on unitarity constraints for such couplings.

Higgs or neutral vector boson production with a W pair in γγ collisions

Exploiting the fact that W pair production in high-energy γγ collisions is very large, we use this process to trigger Higgs, Z or photon radiation. We find that there are sizeable rising cross-sections for triple bosons production. At energies about 1 TeV the new mechanism for Higgs production becomes very competitive with the dominant Higgs production processes in e+e− and eγ reactions. The effect of different polarized photon spectra obtained through back-scattered laser light on the electron beam of a linear collider is investigated. We give special attention to the search of the intermediate mass Higgs in WWH production and discuss how to effectively suppress the backgrounds.

Studying the triple-Higgs vertex in the process γγ→HH at TeV energies

In the frameworl of the equivalence theorem the one-loop helicity amplitudes and cross section for the double Higgs production process γγ→HH are calculated. It is shown that the cross section is measurable at TeV γγ colliders and is marginally sensitive to the triple-Higgs variation.

Initial-state radiation at LEP energies and the corrections to Higgs boson production

It is shown that for e +e − scattering processes described by the exchange of one photon or vector boson the O(α) radiative corrections to the initial state completely factorize the lowest-order cross section. This factorization holds for both hard and soft (or virtual) photons. We present a formalism for applying these radiative corrections in a process-independent way, and described the corresponding computer program. As an application we study the initial-state radiative corrections to the Higgs production processes e +e − → μ + μ −H and e +e − → e +e −H.

Production of very massive Higgs bosons

We compare Higgs boson production mechanisms at multi-TeV hadronic colliders. In addition to the previously investigated processes gluon + gluon → H and q q → V ∗ → VH( V = W, Z) , we consider Higgs boson formation by pairs of virtual W's or Z's, a process analogous to two-photon collisions in e +e − scattering. The Higgs production process W ∗ W ∗ → H is dominated by longitudinal W's and is the most important mechanism for M H > 6 M W, if the top quark mass is about 30 GeV.

Technicolour versus Higgs signatures in e +e − collisions

We study the production signatures of a colour singlet neutral pseudo-Goldstone boson together with a heavy fermion pair in e +e − collisions. The results are contrasted to the signatures of the corresponding Higgs production process.