No Arabic abstract
In this work we present the computation of the Higgs decay into a photon and a $Z^0$ boson at one-loop level in the framework of the Next-to-Minimal Supersymmetric Standard Model (NMSSM). The numerical evaluation of this decay width was performed within the framework of the SloopS code, orginally developped for the Minimal Supersymmetric Standard Model (MSSM) but which was recently extended to deal with the NMSSM. Thanks to the high level of automation of SloopS all contributions from the various sector of the NMSSM are consistently taken into account, in particular the non-diagonal chargino and sfermion contributions. We then explored the NMSSM parameter space, using HiggsBounds and HiggsSignals, to investigate to which extent these signal can be enhanced.
We present the full next-to-leading order (NLO) supersymmetric (SUSY) electroweak and SUSY-QCD corrections to the decay widths of the charged Higgs boson decays into on-shell final states in the framework of the CP-conserving and CP-violating Next-to-Minimal Supersymmetric Model (NMSSM). The newly calculated corrections have been implemented in the code NMSSMCALCEW. In these proceedings, we discuss the impact of the NLO corrections on the charged Higgs boson branching ratios in a wide range of the parameter space that is still compatible with the experimental constraints. We also investigate the effect of CP violation in these corrections.
A light vector boson, Z_d, associated with a dark sector U(1)_d gauge group has been introduced to explain certain astrophysical observations as well as low energy laboratory anomalies. In such models, the Higgs boson may decay into X+Z_d, where X=Z, Z_d or gamma. Here, we provide estimates of those decay rates as functions of the Z_d coupling through either mass-mixing (e.g. via an enlarged Higgs mechanism) or through heavy new fermion loops and examine the implied LHC phenomenology. Our studies focus on the higher m_{Z_d} case, > several GeV, where the rates are potentially measurable at the LHC, for interesting regions of parameter spaces, at a level complementary to low energy experimental searches for the Z_d. We also show how measurement of the Z_d polarization (longitudinal versus transverse) can be used to distinguish the physics underlying these rare decays.
The significance of new physics appearing in the loop-induced decays of neutral Higgs bosons into pairs of dibosons $gammagamma$ and $Zgamma$ will be discussed in the framework of the 3-3-1 models based on a recent work~cite{Okada:2016whh}, where the Higgs sector becomes effectively the same as that in the two Higgs doublet models (2HDM) after the first symmetry breaking from $SU(3)_L$ scale into the electroweak scale. For large $SU(3)_L$ scale $v_3simeq10$ TeV, dominant one-loop contributions to the two decay amplitudes arise from only the single charged Higgs boson predicted by the 2HDM, leading to that experimental constraint on the signal strength $mu^{331}_{gammagamma}$ of the Standard Model-like Higgs boson decay $hrightarrow gammagamma$ will result in a strict upper bound on the signal strength $mu^{331}_{Zgamma}$ of the decay $hrightarrow, Zgamma$. For a particular model with lower $v_3$ around 3 TeV, contributions from heavy charged gauge and Higgs bosons may have the same order, therefore may give strong destructive or constructive correlations. As a by-product, a deviation from the SM prediction $|mu^{331}_{gammagamma}-1| le 0.04$ still allows $|mu^{331}_{Zgamma}-1|$ to reach values near 0.1. We also show that there exists an $CP$-even neutral Higgs boson $h^0_3$ predicted by the 3-3-1 models, but beyond the 2HDM, has an interesting property that the branching ratio Br$(h^0_3rightarrow gammagamma)$ is very sensitive to the parameter $beta$ used to distinguish different 3-3-1 models.
We compute the full next-to-leading order supersymmetric (SUSY) electroweak (EW) and SUSY-QCD corrections to the decays of CP-odd NMSSM Higgs bosons into stop pairs. In our numerical analysis we also present the decay of the heavier stop into the lighter stop and an NMSSM CP-odd Higgs boson. Both the EW and the SUSY-QCD corrections are found to be significant and have to be taken into account for a proper prediction of the decay widths.
Physics beyond the Standard Model (SM) may manifest itself as small deviations from the SM predictions for Higgs signal strengths at 125 GeV. Then, a plausible and interesting possibility is that the Higgs sector is extended and at the weak scale there appears an additional Higgs boson weakly coupled to the SM sector. Combined with the LEP excess in $e^+e^-to Z(hto bbar b)$, the diphoton excess around 96 GeV recently reported by CMS may suggest such a possibility. We examine if those LEP and CMS excesses can be explained simultaneously by a singlet-like Higgs boson in the general next-to-minimal supersymmetric Standard Model (NMSSM). Higgs mixing in the NMSSM relies on the singlet coupling to the MSSM Higgs doublets and the higgsino mass parameter, and thus is subject to the constraints on these supersymmetric parameters. We find that the NMSSM can account for both the LEP and CMS excesses at 96 GeV while accommodating the observed 125 GeV SM-like Higgs boson. Interestingly, the required mixing angles constrain the heavy doublet Higgs boson to be heavier than about 500 GeV. We also show that the viable region of mixing parameter space is considerably modified if the higgsino mass parameter is around the weak scale, mainly because of the Higgs coupling to photons induced by the charged higgsinos.