arXiv subjects

Souad Taj

Publications and source records attributed to Souad Taj.

4 recordsLinked to original sources

arXiv2026

Generation and Enhancement of Bipartite and Tripartite Entanglement in an Electro-Optomechanical Ring Cavity

This study investigates the generation and enhancement of quantum entanglement in an electro-optomechanical ring cavity system. The setup integrates two Coulomb-coupled mechanical resonators, which serve as the fundamental mechanism for the generation of bipartite and tripartite entanglement via charge mediated coupling. We then demonstrate the significant enhancement of this entanglement via a nonlinear parametric drive (an optical parametric amplifier, OPA), which injects a controllable nonlinearity into the cavity. We derive the system's Hamiltonian and the corresponding quantum Langevin equations, which are linearized around steady-state solutions to analyze Gaussian quantum fluctuations. Employing the covariance matrix formalism, we quantify bipartite entanglement via logarithmic negativity and tripartite entanglement via the minimum residual contangle. Our results unequivocally show that while the Coulomb interaction is indispensable for creating entanglement, the OPA acts as a powerful control tool, dramatically amplifying the degree of quantum correlations for all subsystems. We find that the strength of entanglement is highly sensitive to several parameters and can be optimized through the strategic selection of the OPA's gain and phase, the laser detuning, and the input power. A key finding is the existence of a trade-off, where parameters that maximize entanglement also constrain the stable operating regime of the system. Furthermore, thermal noise is shown to progressively degrade all quantum correlations, underscoring the necessity for low-temperature operation. These findings provide comprehensive guidance for parameter optimization, outlining a clear path from generation to enhancement, and highlight the potential of such hybrid systems as versatile platforms for controlling multipartite entanglement in quantum technologies.

quant-ph↗

arXiv2022

Search for charged Higgs boson in $μν$ channel within 2HDM type-III

We discus the muonic decay of light charged Higgs boson for $m_{H^\pm}\le m_t-m_b$ in the context of the generic two Higgs doublet model (2HDM) type-III. We show that for both alignment limit scenarios, the $H^\pm\toμν$ signal could be dominant and give alternative reachable signatures to those arising from top quark production and decay.

hep-ph↗

arXiv2021

New charged Higgs boson discovery channel at the LHC

The ATLAS and CMS experiments have an ambitious search program for charged Higgs bosons. The two main searches for $H^\pm$ at the LHC have traditionally been performed in the $τν$ and $t b$ decay channels, as they provide the opportunity to probe complementary regions of the Minimal SuperSymmetric Model (MSSM) parameter space. Charged Higgs bosons may decay also to light quarks, $H^\pm \to cs/cb$, which represent an additional probe for the mass range below $m_t$. In this work, we focus on $H^\pm \to μν$ as an alternative channel in the context of two Higgs doublet model type III. We explored the prospect of looking $pp\to tb H^\pm$, followed by $H^\pm\toμν$ signal at the LHC. Such a scenario appears in 2HDM type-III where couplings of the charged Higgs are enhanced to $μν$. Almost all the experimental searches rely on the production and decay of the charged Higgs are taken into account. We show that for a such scenario, the above signal is dominant for most of the parameter space, and $H^\pm \to μν$ can be an excellent complementary search. Benchmarks points are proposed for further Monte Carlo analysis.

hep-ph↗

arXiv2021

Signature of 2HDM at Higgs Factories

The full one-loop corrections, both the weak and QED corrections, to the process $e^+ e^- \to Z ϕ$ ($ϕ=h^0,H^0$) in the two Higgs doublet model (2HDM) at the Higgs factories are presented. Up to the $O(α_{em})$ level, the virtual corrections are evaluated by using the FeynArts/FormCalc packages. The real emission corrections are computed using the Feynman Diagram Calculation (FDC) package and the collinear divergences are regularized by the structure functions of an electron. Using the FeynArts/FormCalc and the FDC packages, we study the corrections in the Standard Model (SM) and the 2HDM, respectively. Gauge dependence arising in the normalization of mixing angles is removed by using the pinch technique. After taking into account experimental constraints from the current LHC data, we propose four interesting benchmark scenarios for future colliders. By using these benchmark scenarios, we evaluate the deviation of $Δσ(e^+ e^- \to Z ϕ)$ from their SM values. We also examine Higgs boson decays $ϕ\to b\bar{b}$ and $ϕ\to τ^+τ^-$, which can have large electroweak (EW) contributions from triple Higgs couplings which are absent in the SM. It is found that for these benchmark scenarios, both EW and real emission corrections are sizeable and could be measured at a future $e^+ e^-$ colliders such as the ILC, CLIC, and CEPC.

hep-ph↗