No Arabic abstract
In these proceedings I explore one aspect of gauge-boson physics at the LHC - Triple Gauge-boson Couplings (TGCs) in $WZ$ and Wgamma production. Methods for extracting confidence limits on anomalous TGCs are assessed, while accounting for the effects of higher order QCD corrections and contributions from other theoretical and detector related systematics. Detector response has been parametrised according to the ATLAS detectors specifications. A strategy for reporting the anomalous coupling limits is introduced which removes the ambiguities of form factors by reporting the limits as a function of a cutoff operating on the diboson system invariant mass. Techniques for measuring the energy dependence of anomalous couplings are demonstrated.
We present the results obtained by the Triple Gauge Couplings working group during the LEP2 Workshop (1994-1995). The report concentrates on the measurement of $WWgamma$ and $WWZ$ couplings in $e^-e^+to W^-W^+$ or, more generally, four-fermion production at LEP2. In addition the detection of new interactions in the bosonic sector via other production channels is discussed.
In extended Higgs sectors that exhibit alignment without decoupling, the additional scalars are allowed to have large couplings to the Standard Model Higgs. We show that current nonresonant di-Higgs searches can be straightforwardly adapted to look for additional Higgses in these scenarios, where pair production of non-SM Higgses can be enhanced. For concreteness, we study pair production of exotic Higgses in the context of an almost inert two Higgs doublet model, where alignment is explained through an approximate $mathbb{Z}_2$ symmetry under which the additional scalars are odd. In this context, the smallness of the $mathbb Z_2$ violating parameter suppresses single production of exotic Higgses, but it does not prevent a sizeable trilinear coupling $hHH$ between the SM Higgs ($h$) and the additional states ($H$). We study the process $pprightarrow h^* rightarrow HH$ in the final states $bbar b b bar b$, $bbar bgammagamma$, and multi-leptons. We find that at the HL-LHC these modes could be sensitive to masses of the additional neutral scalars in the range $130mbox{ GeV} lesssim m_H lesssim 290mbox{ GeV}$.
The anomalous neutral triple gauge boson couplings (aNTGCs) for the Z gamma gamma and Z gamma Z vertices described by dimension-eight operators are examined through the process pp to l^{+}l^{-} gamma at the High-Luminosity Large Hadron Collider (HL-LHC). We performed an analysis on transverse momentum of photon and angular distribution of charged lepton in the final state including detector effects. Sensitivity limits of the C_{widetilde{B}W}, C_{BB} couplings are obtained at 95 % C.L. to constrain for the range [-1.88: 1.88] TeV^{-4}, [-1.47: 1.47] TeV^{-4} and [-1.14:1.14] TeV^{-4}, [-0.86: 0.86] TeV^{-4} with an integrated luminosity of 300 fb^{-1} and 3000 fb^{-1}, respectively.
Triple gauge boson associated production at the LHC serves as an interesting channel to test the robustness of the Standard Model. Any deviation from its SM prediction may indicate possible existence of relevant new physics, e.g., anomalous quartic gauge boson couplings. In this paper, a Monte-Carlo feasibility study of measuring WWA production with pure leptonic decays and probing anomalous quartic gauge-boson (e.g., WWAA) couplings, is presented in detail for the first time, with parton shower and detector simulation effects taken into account. Our results show that at the sqrt{s} = 14 TeV LHC with an integrated luminosity of 100 (30) fb-1, one can reach a significance of 9 (5) sigma to observe the SM WWA production, and can constrain at the 95% CL the anomalous WWAA coupling parameters, e.g., a_{0,c}^W/Lambda^2 (see Ref.[15] for their definitions), at 10^{-5} GeV^{-2}, respectively.
In the framework of effective Lagrangians with the SU(2)_L x U(1)_Y symmetry linearly realized, modifications of the couplings of the Higgs field to the electroweak gauge bosons are related to anomalous triple gauge couplings (TGCs). Here, we show that the analysis of the latest Higgs boson production data at the LHC and Tevatron give rise to strong bounds on TGCs that are complementary to those from direct TGC analysis. We present the constraints on TGCs obtained by combining all available data on direct TGC studies and on Higgs production analysis. Note added: The analysis has been updated with all the public data available as November 2013. Updates of this analysis are provided at http://hep.if.usp.br/Higgs