We review activities in the field of theoretical, phenomenological and experimental studies related to the production of the Higgs boson in central exclusive processes at LHC in models beyond Standard Model. Prospects in the context of the Higgs boson discovery at LHC in 2012 and of proposals to build forward proton detectors at ATLAS and CMS side are summarized.
The prospects for central exclusive diffractive (CED) production of MSSM Higgs bosons at the LHC are reviewed. It is shown that the CED channels, making use of forward proton detectors at the LHC installed at 220 m and 420 m distance around ATLAS and / or CMS, can provide important information on the Higgs sector of the MSSM. In particular, CED production of the neutral CP-even Higgs bosons h and H and their decays into bottom quarks has the potential to probe interesting regions of the M_A--tan_beta parameter plane of the MSSM and may give access to the bottom Yukawa couplings of the Higgs bosons up to masses of M_H approx 250 GeV.
A recent preliminary investigation based on Durguts report at the American Physical Society site shows a structure at $18.4~ {rm GeV}$ exists in the invariant mass distribution of $Upsilon l^+l^- ~ (l = e,, mu)$ at the LHC center-of-mass energy of $7$ and $8~ {rm TeV}$. Its appearance attracts attention of theorists and experimentalists of high energy physics, because it might be a Higgs-like boson of $18.4~ {rm GeV}$ which would serve as a signal of the new physics beyond the Standard Model. We have carried out computations on the corresponding quantities (production and decay rates) based on quantum field theory and compared the results with experimental data. Our numerical results do not support the assertion that the $18.4~ {rm GeV}$ peak corresponds to a neutral $0^{++}$ boson which decays into $Upsilon l^+l^-$. Much further works (both experimental and theoretical) are badly needed.
The prospects for central exclusive diffractive (CED) production of MSSM Higgs bosons at the LHC are reviewed. These processes can provide important information on the $cp$-even Higgs bosons, allowing to probe interesting regions of the $MA$--$tb$ parameter plane. The sensitivity of the searches in the forward proton mode for the Higgs bosons in the so-called CDM-benchmark scenarios and the effects of fourth-generation models on the CED Higgs production are briefly discussed.
We consider the Higgs boson decay processes and its production, and provide a parameterisation tailored for testing models of new physics beyond the Standard Model. We also compare our formalism to other existing parameterisations based on scaling factors in front of the couplings and to effective Lagrangian approaches. Different formalisms allow to best address different aspects of the Higgs boson physics. The choice of a particular parameterisation depends on a non-obvious balance of quantity and quality of the available experimental data, envisaged purpose for the parameterisation and degree of model independence, importance of the radiative corrections, scale at which new particles appear explicitly in the physical spectrum. At present only simple parameterisations with a limited number of fit parameters can be performed, but this situation will improve with the forthcoming experimental LHC data. Detailed fits can only be performed by the experimental collaborations at present, as the full information on the different decay modes is not completely available in the public domain. It is therefore important that different approaches are considered and that the most detailed information is made available to allow testing the different aspects of the Higgs boson physics and the possible hints beyond the Standard Model.
We study the Higgs boson pair production through $e^+e^-$ collision in the noncommutative(NC) extension of the standard model using the Seiberg-Witten maps of this to the first order of the noncommutative parameter $Theta_{mu u}$. This process is forbidden in the standard model with background space-time being commutative. We find that the cross section of the pair production of Higgs boson (of intermediate and heavy mass) at the future Linear Collider(LC) can be quite significant for the NC scale $Lambda$ lying in the range $0.5 - 1.0$ TeV. Finally, using the direct experimental(LEP II, Tevatron and global electro-weak fit) bound on Higgs mass, we obtain bounds on the NC scale as 665 GeV $le Lambda le 998$ GeV.