No Arabic abstract
A summary of the Higgs boson searches by the ATLAS and CMS collabrations using 1 f b-1 of LHC data is presented, concentrating on the Standard Model Higgs boson. Both experiments have the sensitivity to exclude at 95% CL a Standard Model Higgs boson in most of the Higgs boson mass region between about 130 GeV and 400 GeV. The observed data allow the exclusion of a Higgs Boson of mass 155 GeV to 190 GeV and 295 GeV to 450 GeV (ATLAS) and 149 GeV to 206 GeV and 300 GeV to 440 GeV (CMS). The lower limits are not as constraining as might be expected due to an excess in both experiments of order 2-3{sigma} which could be related to a low mass Higgs boson or to a statistical fluctuation.
We present results from CDF and D0 on direct searches for high mass standard model (SM) Higgs boson (H) in ppbar collisions at the Fermilab Tevatron at sqrt(s) = 1.96 TeV. Compared to previous Higgs boson Tevatron combinations, more data and new channels (H -> W+W- -> lnujj, H -> WW -> l+tau + X and trilepton final states) have been added. Most previously used channels have been reanalyzed to gain sensitivity. Analyzing 5.9 fb^-1 of data at CDF, and 5.4-6.7 fb^-1 at D0, the combination excludes with 95% C.L. a standard model Higgs boson in the mass range of m_H = 158-175 GeV/c2.
The search for the Higgs boson, both in the context of the standard model and extensions to it, has been a key focus during Run II of the Tevatron. I report on the status of these searches, which are highlighted by evidence at the 3 standard deviation level for the SM Higgs in its $bbar{b}$ decay mode, the strongest direct evidence to date for fermionic couplings of the Higgs boson.
Vector-boson pair production is an important background for Higgs boson and new physics searches at the Large Hadron Collider LHC. We have calculated the loop-induced gluon-fusion process gg -> WW -> leptons, allowing for arbitrary invariant masses of the intermediate W bosons. This process contributes at O(alpha_s^2) relative to quark-antiquark annihilation, but its importance is enhanced by the large gluon flux at the LHC and by experimental cuts employed in Higgs boson searches. We find that gg -> WW provides only a moderate correction (ca. 5%) to the inclusive W-pair production cross section at the LHC. However, after taking into account realistic experimental cuts, the gluon-fusion process becomes significant and increases the theoretical WW background estimate for Higgs searches in the pp -> H -> WW -> leptons channel by approximately 30%.
We propose six new benchmark scenarios for Higgs boson searches in the Minimal Supersymmetric Standard Model. Our calculations follow the recommendations of the LHC Higgs Cross Section Working Group, and benefit from recent developments in the predictions for the Higgs-boson masses and mixing. All of the proposed scenarios are compatible with the most recent results from Run 2 of the LHC. In particular, they feature a scalar with mass and couplings compatible with those of the observed Higgs boson, and a significant portion of their parameter space is allowed by the limits from the searches for SUSY particles and additional Higgs bosons. We define a scenario where all SUSY particles are relatively heavy, and two scenarios with light colorless SUSY particles (charginos, neutralinos and, in one case, staus). In addition, we present two scenarios featuring alignment without decoupling, realized with either the lighter or the heavier scalar being SM-like, and a scenario with CP violation.
We report on the potential for the discovery of a Standard Model Higgs boson with the vector boson fusion mechanism in the mass range $115<M_H<500 gev/$c$^2$ with the ATLAS experiment at the LHC. Feasibility studies at hadron level followed by a fast detector simulation have been performed for $Hto W^{(*)}W^{(*)}to l^+l^-sla{p_T}$, $Htogammagamma$ and $Hto ZZto l^+l^-qbar{q}$. The preliminary results obtained here show a large discovery potential in the range $115<M_H<300 gev/$c$^2$. Results obtained with multivariate techniques are reported for a number of channels.