No Arabic abstract
We study impacts of dimension-five lepton-number violating operators associated with two same-sign weak bosons, $ell^pm ell^{prime pm} W^mp W^mp$, on current and future experiments for neutrino oscillation, lepton-number violating rare processes and high-energy collider experiments. These operators can contain important information on the origin of tiny neutrino masses, which is independent of that from the so-called Weinberg operator. We examine constraints on the coefficients of the operators by the neutrino oscillation data. Upper bounds on the coefficients are also investigated by using the data for processes of lepton number violation such as neutrinoless double beta decays and $mu^-$-$e^+$ conversion. These operators can also be directly tested by searching for lepton-number violating dilepton production via the same-sign W boson fusion process at high-energy hadron colliders like the Large Hadron Collider. We find that these operators can be considerably probed by these current and future experiments.
We investigate the viability of observing charged Higgs bosons (H^pm) produced in association with W bosons at the CERN Large Hadron Collider, using the leptonic decay H^+ -> tau^+ nu_tau and hadronic W decay, within the Minimal Supersymmetric Standard Model. Performing a parton level study we show how the irreducible Standard Model background from W + 2 jets can be controlled by applying appropriate cuts. In the standard m_h^max scenario we find a viable signal for large tan beta and intermediate H^pm masses (~ m_t).
An $H^pm W^mp Z$ interaction at the tree level is common feature of new physics models that feature scalar triplets. In this study, we aim to probe the strength of the aforementioned interaction in a model-agnostic fashion at the futuristic 27 TeV proton-proton collider. We assume that the $H^pm$ couples dominantly to ($W^pm,Z$) and ($t,b$). We specifically study the processes that involve the $H^pm W^mp Z$ vertex at the production level, that is, $p p to H^pm j j$ and $p p to Z H^pm$. Moreover, we look into both $H^pm to W^pm Z,~t b$ decays for either production process. Our investigations reveal that the $H^pm j j$ production process has a greater reach compared to $Z H^pm$. Moreover, the discovery potential of a charged Higgs improves markedly with respect to the earlier studies corresponding to lower centre-of-mass energies. Finally, we recast our results in the context of the popular Georgi-Machacek model.
In certain new physics scenarios, a singly charged Higgs boson can couple to both fermions and $W^pm Z$ at tree level. We develop new strategies beyond current experimental searches using $ppto jjH^pm$, $H^pm to tb $ at the Large Hadron Collider (LHC). With the effective $H^pm W^mp Z$ and $H^pm tb$ couplings we perform a model-independent analysis at the collision energy $sqrt{s}=13$~TeV with the integrated luminosity of $3~text{ab}^{-1}$. We derive the discovery prospects and exclusion limits for the charged Higgs boson in the mass range from 200~GeV to 1~TeV. With $|F_{WZ}|,|A_t|sim 0.5-1.0$ and $300~text{GeV}lesssim m_{H^pm}lesssim 400~text{GeV}$, we point out that a discovery significance of $5sigma$ can be achieved. The constraints and projected sensitivities are also discussed in a realistic model, i.e., the modified Georgi-Machacek model without custodial symmetry. Our proposed search would provide direct evidence for a charged Higgs boson $H^pm$ that couples to $W^pm Z$ and $tb$, which can have better sensitivity to the couplings of $H^pm W^mp Z$ and $H^pm tb$ than current searches.
Supposing only Lorentz and the gauge invariances of the Lagrangian, we derive energy and angular distributions for $tau^pm to mu^pm mu^pm mu^mp$ lepton flavor violating decay process. Using these results, we discuss methods to determine the parameters associated with the lepton flavor violating interactions.
In this paper we calculate the production of a charged top pion in association with a W boson via gg fusion at the CERN Large Hadron Collider in the context of the topcolor assisted technicolor model. We find that, the total cross section of pp --> gg --> W^{pm}pi_t^{mp}, is several dozen femtobarns with reasonable values of the parameters, and the total cross section of pp --> W^{pm}pi_t^{mp} can reach a few hundred femtobarns when we consider the sum of the contributions of these two parton subprocesses gg --> W^{pm}pi_t^{mp} and bbar{b} --> W^{pm}pi_t^{mp}.