We study an upper bound on masses of additional scalar bosons from the electroweak precision data and theoretical constraints such as perturbative unitarity and vacuum stability in the two Higgs doublet model taking account of recent Higgs boson search results. If the mass of the Standard-Model-like Higgs boson is rather heavy and is outside the allowed region by the electroweak precision data, such a discrepancy should be compensated by contributions from the additional scalar bosons. We show the upper bound on masses of the additional scalar bosons to be about 2 $(1)$ TeV for the mass of the Standard-Model-like Higgs boson to be 240 $(500)$ GeV.
We study the double Higgs boson production processes $e^+e^- to hh fbar{f}$ ($f eq t$) with $h$ being the 125 GeV Higgs boson in the two-Higgs-doublet model with a softly-broken $Z_2$ symmetry. The cross section can be significantly enhanced, typically a few hundreds percent, as compared to the standard model prediction due to resonant effects of heavy neutral Higgs bosons, which becomes important in the case without the alignment limit. We find a strong correlation between the enhancement factor of the cross section and the scaling factor of the $hfbar{f}$ couplings under constraints from perturbative unitarity, vacuum stability and current experimental data at the LHC as well as the electroweak precision data.
At the Large Hadron Collider, we prove the feasibility to detect pair production of the lightest CP-even Higgs boson $h$ of Type II 2-Higgs Doublet Models through $q q^{()}to q q^{()} {hh}$ (vector-boson fusion). We also show that, through the $hhto 4b$ decay channel in presence of heavy-flavour tagging, further exploiting forward/backward jet sampling, one has direct access to the $lambda_{Hhh}$ triple Higgs coupling -- which constrains the form of the Higgs potential.
We study a two scalar inert doublet model (IDMS$_3$) which is stabilized by a $S_3$ symmetry. We consider two scenarios: i) two of the scalars in each charged sector are mass degenerated due to a residual $Z_2$ symmetry, ii) there is no mass degeneracy because of the introduction of soft terms that break the $Z_2$ symmetry. We show that both scenarios provide good dark matter candidates for some range of parameters.
We calculate the cross section of Higgs boson pair production at a photon collider in the two Higgs doublet model. We focus on the scenario in which the lightest CP even Higgs boson ($h$) has the standard model like couplings to the gauge bosons. We take into account the one-loop correction to the $hhh$ coupling as well as additional one-loop diagrams due to charged Higgs bosons to the $gammagammato hh$ helicity amplitudes. It is found that the full cross section can be enhanced by both these effects to a considerable level. We discuss the impact of these corrections on the $hhh$ coupling measurement at the photon collider.
We present a study of triple Higgs boson (3H) production at the International Linear Collider (ILC) within the general Two-Higgs-Doublet Model (2HDM). We compute the production cross-sections at the leading-order for the 3H final states and find values up to sigma ~ 0.1 pb. This result represents a large enhancement with respect to the corresponding MSSM cross-sections, which stay typically at the level of sigma ~ 10^(-6) pb or less. Furthermore, since the 3H cross-sections in the general 2HDM can be of the order of the double Higgs production cross-sections, such 3H processes could be a competitive (if not the dominant) mechanism for Higgs boson production at the ILC. In practice, these 3H events could be identified through the tagging of 6 heavy-quark jet final states and, in this case, they would provide strong evidence of an extended Higgs boson sector -- likely of non-supersymmetric nature.
Shinya Kanemura
,Yasuhiro Okada
,Hiroyuki Taniguchi
.
(2011)
.
"Indirect bounds on heavy scalar masses of the two-Higgs-doublet model in light of recent Higgs boson searches"
.
Koji Tsumura
هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا