No Arabic abstract
The goal of this report is to summarize the current situation and discuss possible search strategies for charged scalars, in non-supersymmetric extensions of the Standard Model at the LHC. Such scalars appear in Multi-Higgs-Doublet models (MHDM), in particular in the popular Two-Higgs-Doublet model (2HDM), allowing for charged and additional neutral Higgs bosons. These models have the attractive property that electroweak precision observables are automatically in agreement with the Standard Model at the tree level. For the most popular version of this framework, Model~II, a discovery of a charged Higgs boson remains challenging, since the parameter space is becoming very constrained, and the QCD background is very high. We also briefly comment on models with dark matter which constrain the corresponding charged scalars that occur in these models. The stakes of a possible discovery of an extended scalar sector are very high, and these searches should be pursued in all conceivable channels, at the LHC and at future colliders.
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.
We review the most relevant LHC searches at $sqrt{s}$ = 8 TeV looking for low mass bosons arising from exotic decay of the Standard Model Higgs and highlighting their impact on both supersymmetric and not supersymmetric Beyond the Standard Model scenarios.
We review the study of the charged Higgs and top quark associated production at the LHC with the presence of an additional scalar doublet. Top quark spin effects are related to the Higgs fermion couplings through this process. The angular distributions with respect to top quark spin turn out to be distinctive observables to study the $Htb$ interaction in different models.
We review the current strategies to search for generic SUSY models with R-parity conservation in the ATLAS and CMS detectors at the LHC. The discovery reach in early data will be presented for the different search channels based on missing transverse momentum from undetected neutralinos and multiple jets. We will also describe the search for models of gauge-mediated supersymmetry breaking for which the NLSP is a neutralino decaying to a photon and a gravitino. Finally, we will present recent work on techniques used to reconstruct the decays of SUSY particles at the LHC in early data, based on the selection of final-state exclusive decay chains.
A very light (GeV scale) dark gauge boson ($Z$) is a recently highlighted hypothetical particle that can address some astrophysical anomalies as well as the $3.6 sigma$ deviation in the muon $g$-2 measurement. We suggest top quark decays as a venue to search for light dark force carriers at the LHC. Such $Z$s can be easily boosted, and they can decay into highly collimated leptons (lepton-jet) with large branching ratio. We investigate a scenario where a top quark decays to $b W$ accompanied by one or multiple dark force carriers and find that such a scenario could be easily probed at the early stage of LHC Run 2.