arXiv subjects

Marwa Telba

Publications and source records attributed to Marwa Telba.

4 recordsLinked to original sources

arXiv2026

Multi-Channel Di-Higgs Production in the scNMSSM: From Exotic 8b to Boosted 8tau Signatures at the HL-LHC

We investigate multi-channel di-Higgs signal prospects in the semi-constrained Next-to-Minimal Supersymmetric Standard Model (scNMSSM) at large-lambda/low-tan(beta) at the HL-LHC with sqrt(s) = 13.6 TeV and L = 3000 fb^{-1}. Building on our previous work, four benchmark points are selected from 66 viable SM-like candidates, spanning three di-Higgs topologies: exotic multi-b (h1h1 -> 4a1 -> 8b, BP1/BP3), boosted multi-tau (h1h1 -> 4a1 -> 8tau, BP2), and SM-like (BP4). A complete signal simulation chain (MadGraph5_aMC@NLO + Pythia 8.316 + Delphes 3) is employed for 10^5 signal events per benchmark point. Background yields are estimated from published LHC analyses and are used only for indicative sensitivity projections. For the 8b topology (BP1: m_{a1} = 47.4 GeV, BP3: m_{a1} = 51.9 GeV), b-jet efficiencies of epsilon(>=4b) ~ 14% yield S ~ 14,000-16,000 events, potentially compatible with 5-sigma sensitivity under the simplified background model adopted. For the boosted 8tau topology (BP2: m_{a1} = 8.2 GeV), 82.4% of same-a1 tau-pairs have Delta R(tau,tau) < 0.4, below the standard jet cone radius, due to the large Lorentz boost gamma ~ 7.5. This topology yields epsilon(>=2tau) = 38.4%, a factor of ~21 above the SM baseline, but requires dedicated boosted a1 taggers due to irreducible multi-tau backgrounds. BP4 serves as a SM-like reference, consistent with existing HL-LHC HH projections. The Higgs self-coupling modifier kappa_lambda in [0.884, 0.951] is universally suppressed below unity. The boosted a1 topology of BP2 is not covered by any existing ATLAS or CMS di-Higgs search, strongly motivating dedicated sub-jet analysis strategies at the HL-LHC.

hep-ph↗

arXiv2026

Di-Higgs Production and Trilinear Higgs Self-Coupling in the scNMSSM: Qualitative Implications for the Electroweak Phase Transition at large {\lambda} and Low tan\b{eta}

The trilinear Higgs self-coupling and di-Higgs production cross section are investigated in the semi-constrained NMSSM (scNMSSM) at large-$\lambda$ / low-$\tan\beta$ with full two-loop precision. A random scan of one million parameter points subject to theoretical, collider, flavor, and dark matter constraints yields 66 SM-like points with singlet fraction $S_{13}^2 < 0.05$, all found in the mass range $m_{h_1} \in [122.0,\,125.0]~\text{GeV}$ --- a feature that reflects an intrinsic property of the scNMSSM at large-$\lambda$ / low-$\tan\beta$, where doublet-dominated configurations are kinematically confined below ${\sim}125~\text{GeV}$. The trilinear coupling ratio is found to be universally suppressed: $\kappa_\lambda = 0.884$--$0.982$, $\langle\kappa_\lambda\rangle = 0.944 \pm 0.018$. The non-resonant di-Higgs cross section at $\sqrt{s} = 13.6~\text{TeV}$ lies in the range $30.3$--$36.9~\text{fb}$ ($0.88$--$1.05\,\sigma_{\rm SM}$), with the resonant contribution via $gg \to h_3 \to h_1h_1$ negligible ($\leq 0.004~\text{fb}$). All predictions are consistent with current ATLAS+CMS di-Higgs upper limits and is expected to be probed at the HL-LHC. These results are discussed in the context of the electroweak phase transition, where the universal suppression of $\kappa_\lambda$ is qualitatively consistent with a modified Higgs potential that could support a strengthened first-order transition. A quantitative determination of the phase transition strength via finite-temperature analysis is left for future work.

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arXiv2021

Fermionic decays of NMSSM Higgs bosons under LHC 13 TeV constraints

This paper investigates the impact of the recent LHC constraints on the Higgs sector in the semi-constrained version of the Next-to-Minimal Supersymmetric Standard Model. Our analysis focuses on the parameter space for which the value of the Higgs doublet-singlet coupling, $λ$, is large as possible, while the ratio between the vacuum expectation values of the two Higgs doublets, $\tanβ$, is small as possible. Under the current constraints, we present the possible fermionic decay channels and reduced cross-section into fermions final states for the lightest neutral Higgs bosons in the NMSSM, $(h_{1}$, $h_{2}$, and $a_{1})$. We found that the branching ratios of the non SM-like Higgs ($a_{1}$ and $h_{2}$) into a pair of bottom quarks are near 90\% level when the Higgs mass below 400 GeV. Moreover, the branching ratio of $h_{2}/a_{1}\rightarrow t\bar{t}$ can reach unity for all mass ranges when these bosons are mostly singlet.

hep-ph↗

arXiv2021

Impact of LHC Higgs couplings measurements on bosonic decays of the neutral Higgs sector in the scNMSSM

We analyze the Next-to-minimal supersymmetric standard model with Grand unification boundary conditions under current theoretical and experimental constraints. We compute the mass spectrum of the model and focus on the three lightest particles in the Higgs sector (two CP-even scalars, $h_1, h_2$, and one CP-odd, $a_1$). The reduced couplings of such particles, singlet-doublet components, their branching ratios to bosons, and reduced cross-section to photons and massive gauge bosons via gluon fusion are thoroughly and systematically scrutinized. Our analysis is focused on the parameter space where the singlet-doublet coupling $λ$ is as large as possible (keeping the perturbativity bound intact) and the ratio between the vacuum expectation values of the up-type and down-type Higgses ($\tanβ$) is as small as possible, which is the region representing the most natural case of the NMSSM. We show the impact of recent constraints from the LHC on the SM-Higgs couplings to bosons and fermions on the parameter space of the model and the consequent implications on the Higgs sector. The results show that while the model is still able to account for current data and provide an opportunity for discovery of extended Higgs sectors, recent LHC Higgs couplings constraints rule-out parts of the parameter space where $h_2$ (non-SM-like) and $a_1$ are non-singlet with masses below ~400 GeV.

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