Pseudo goldstones at future colliders from the extended BESS model

Decays and branching ratios of light neutralino production in $Z_R^0 \to \tilde \chi _i^0 \tilde \chi _j^0 $ in the left-right super-symmetric model are considered. We study in detail the signatures of one and two sided events in $Z_R^0 \to \tilde \chi _1^0 \tilde \chi _2^0 $ and $Z_R^0 \to \tilde \chi _2^0 \tilde \chi _2^0 $ respectively, and their dependence on the parameters of the light neutralino mixing matrix.     

Jet quenching pattern at LHC in PYQUEN model

The first LHC data on high transverse momentum hadron and dijet spectra in PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed in the frameworks of PYQUEN jet quenching model. The presented studies for the nuclear modification factor of high-p _T hadrons and the imbalance in dijet transverse energy support the supposition that the intensive wide-angular (“out-of-cone”) medium-induced partonic energy loss is seen in central PbPb collisions at the LHC.     

Supersymmetry at the LHC

The success of supersymmetry is beyond any doubt. With the availability of the precise measurement of the dark-matter content of the universe, SUSY models are used as cosmological connection to particle physics. We are now ready to verify this theory directly at the upcoming large hadron collider (LHC). It is possible to use the LHC measurements to reconstruct the SUSY model parameters. These parameters will then be used to calculate the relic density very precisely to be compared with the dark-matter content measured from the astrophysical measurements. In this review, I will summarize various search strategies which will be important to measure supersymmetry parameters in different models in order to establish the cosmological connection.     

SUSY at the LHC

I discuss part of the program of work towards discoveries at the LHC with seeds for orientation and navigation in the parameter space given an anticipated multitude of excesses at start-up.     

Probing the Higgs sector of $$$$ Higgs triplet model at LHC

In this paper, we investigate the Higgs Triplet Model with hypercharge \(Y_{\varDelta }=0\) (HTM0), an extension of the Standard model, caracterized by a more involved scalar spectrum consisting of two CP even Higgs \(h^0, H^0\) and two charged Higgs bosons \(H^\pm \). We first show that the parameter space of HTM0, usually delimited by combined constraints originating from unitarity and BFB as well as experimental limits from LEP and LHC, is severely reduced when the modified Veltman conditions at one loop are also imposed. Then, we perform an rigorous analysis of Higgs decays either when \(h^0\) is the SM-like or when the heaviest neutral Higgs \(H^0\) is identified to the observed 125 GeV Higgs boson at LHC. In these scenarios, we perform an extensive parameter scan, in the lower part of the scalar mass spectrum, with a particular focus on the Higgs to Higgs decay modes \(H^0 \rightarrow h^0h^0, H^\pm \,H^\mp \) leading predominantly to invisible Higgs decays. Finally, we also study the scenario where \(h^0, H^0\) are mass degenerate. We thus find that consistency with LHC signal strengths favours a light charged Higgs with a mass about 176–178 GeV. Our analysis shows that the diphoton Higgs decay mode and \(H \rightarrow Z \gamma \) are not always positively correlated as claimed in a previous study. Anti-correlation is rather seen in the scenario where h is SM like, while correlation is sensitive to the sign of the potential parameter \(\lambda \) when H is identified to 125 GeV observed Higgs.     

Phenomenological study of $$Z'$$ in the minimal $$B-L$$B-L model at LHC

The phenomenological study of neutral heavy gauge boson (\(Z^{\prime }_{B-L}\)) of the minimal \(B-L\) extension was done in the context of the LHC, on the dimuon production channel. The study begins with the LEP-II constraints on \(Z'\) searches, and the dimuon events are simulated at the parton level at CM energies of 7 TeV and 8 TeV and studied with an integrated luminosity of 1.21 fb\(^{-1}\) and 20.5 fb\(^{-1}\) respectively. Later, the ATLAS detector-specific cuts unique to the muon pairs are imposed followed by the signal selection cuts on the invariant mass of the dimuon which restrict the events that are to be passed for signal-background analysis, that are finally compared with the ATLAS data, and accounted for no experimental detection of \(Z^{\prime }_{B-L}\) boson. It has been simulated further at 14 TeV CM energy with an integrated luminosity of 300 fb\(^{-1}\) to predict a possible discovery of this \(B-L\) neutral-heavy gauge boson with a mass corresponding to 1.5 TeV and a \(Z'\) coupling strength of 0.2 based on the signal-background analysis.     

Inelastic diffraction at the LHC

The relativistic scattering was one of the scientific fields where Academician V.G. Kadyshevsky has made an important and highly cited contribution [1]. In this paper we discuss the high-energy dependencies of diffractive and non-diffractive inelastic cross-sections in view of the recent LHC data which reveal a presence of the reflective scattering mode.     

Di-photon Higgs signals at the LHC in the next-to-minimal supersymmetric standard model

The NMSSM contains a Higgs singlet in addition to the two Higgs doublets typical of the MSSM, thus resulting in a total of seven physical Higgs mass states. Therefore, the phenomenology of the NMSSM Higgs sector can differ considerably from that of the MSSM, and there are good prospects of finding in regions of the NMSSM parameter space Higgs signals that cannot be reproduced in the MSSM. We examined here the two-photon decay mode of a Higgs boson and found that up to three neutral Higgs states, heavy and/or light, could be simultaneously observable at the LHC, a possibility precluded to the MSSM. There are also some possibilities that only the lightest NMSSM Higgs boson be detectable via this mode, with a mass beyond the upper limit of the corresponding MSSM state, thus also allowing one to distinguish between the two scenarios. However, in most of the NMSSM parameter space the configurations of the non-minimal model are not very different from those arising in the minimal case.     

Higgs searches at the LHC

We review the prospects for searches of the Standard Model Higgs boson at the LHC, based on detailed studies performed by the ATLAS and CMS Collaborations. The search channels and strategies are described, resulting in the assessment of the discovery potential for the two experiments. We discuss the prospects for measurements in the Higgs sector. To cite this article: A. De Roeck, G. Polesello, C. R. Physique 8 (2007).     

Quantum gravity at the LHC

We study the production of massless gravitons at the LHC and compare our results to those obtained in extra-dimensional models. The signature in both cases is missing energy plus jets. In case of non-observation, the LHC could be used to put the tightest limit to date on the value of the Planck mass.     

Higgs bosons at the LHC

The investigation of the dynamics responsible for electroweak symmetry breaking is one of the prime tasks of the experiments at the CERN Large Hadron Collider (LHC). In this article, the potential of the ATLAS and CMS experiments for the discovery of a standard model Higgs boson and for Higgs bosons in the minimal supersymmetric extension is summarized. Emphasis is put on those studies which have been performed recently by the experimental collaborations using a realistic simulation of the detector performance. This includes a discussion of the search for Higgs bosons using the vector boson-fusion mode, a discussion on the measurement of Higgs boson parameters as well as a detailed review of the MSSM sector for different benchmark scenarios.     

signal of NMSSM at the LHC

For the Benjamin Ono equation, the Hirota bilinear method and long wave limit method are applied to obtain the breathers and the rogue wave solutions. Bright and dark rogue waves exist in the Benjamin Ono equation, and their typical dynamics are analysed and illustrated. The semirational solutions possessing rogue waves and solitons are also obtained, and demonstrated by the three-dimensional figures. Furthermore, the hybrid of rogue wave and breather solutions are also found in the Benjamin Ono equation.     

RS model with a small curvature and dielectron production at the LHC

In the framework of the Randall-Sundrum-like scenario with the small curvature κ (RSSC model), p _⊥-distributions for the dielectron production at the LHC are calculated. For the summary statistics taken at 7 TeV (L = 5 fb^?1) and 8 TeV (L = 20 fb^?1), the exclusion limit on the 5-dimensional gravity scale M ₅ is found to be 6.35 TeV at 95% C.L. For √s = 13 TeV and integrated luminosity 30 fb^?1, the LHC search limit is estimated to be 8.95 TeV. These limits on M ₅ are independent of κ, provided the relation κ ? M ₅ is satisfied.     

Top quark production in extended BESS model

We study top production at Tevatron collider in the extended BESS model, which is an effective lagrangian parametrization of a dynamical symmetry breaking of the electroweak symmetry. The existence of a colored octet of gauge vector bosons can increase top production at a rate still consistent with recent experimental data and lead to distorsions in the transverse momentum spectrum of the top.     

Higgs physics at LHC

The large hadron collider (LHC) and its detectors, ATLAS and CMS, are being built to study TeV scale physics, and to fully understand the electroweak symmetry breaking mechanism. The Monte-Carlo simulation results for the standard model and minimal super symmetric standard model Higgs boson searches and parameter measurements are discussed. Emphasis is placed on recent investigations of Higgs produced in association with top quarks and in vector boson fusion channels. These results indicate that Higgs sector can be explored in many channels within a couple of years of LHC operation, i.e.,L = 30 fb⁻¹. Complete coverage including measurements of Higgs parameters can be carried out with full LHC program.