arXiv subjects

Thi Nhung Dao

Publications and source records attributed to Thi Nhung Dao.

At least 19 recordsLinked to original sources

arXiv2026

Triply polarized $WWW$ at the LHC: first glimpse at LO

We present first results for triply polarized $WWW$ events at the LHC. The calculation is performed at leading order for fully leptonic decays using the Standard Model (SM). Employing an inclusive kinematic cut setup, we found that the triply-transverse polarization fraction is about $51\%$, while the triply-longitudinal (LLL) fraction is smallest with $1.4\%$ for the $W^-W^+W^+$ process. The interference between different polarization amplitudes amounts to $+1.8\%$. Results for the $W^+W^-W^-$ case are similar. On the technical side, a new general on-shell mapping for multi-resonance processes, being a crucial element of polarized cross-section calculation, is also presented. Finally, comparisons with the results of MoCaNLO and Sherpa are provided, showing good agreements.

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arXiv2026

NMSSMScanner: Efficient Scans in the NMSSM Parameter Space Proof of Concept

We present the first version of the new scanning tool NMSSMScanner that allows to perform efficient scans in the complex multi-parameter space of the Next-to-Minimal Supersymmetric extension of the Standard Model (NMSSM) while taking into account all relevant constraints. As a proof of concept we apply it to the search for NMSSM parameter configurations that maximize Higgs boson pair production from resonant scalar or pseudoscalar production in various final states.

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arXiv2025

Theory overview on polarization and spin-correlations in multi-boson processes

In this contribution, we summarize and discuss recent theoretical progress on the Standard-Model calculation of joint polarized cross sections of massive multi-boson processes with fully leptonic decays. The topics include fixed-order calculation of higher order QCD and electroweak corrections for both production and decay amplitudes, and parton-shower effects.

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arXiv2025

Loop-corrected Trilinear Higgs Self-Couplings in the NMSSM with Inverse Seesaw Mechanism

The higher-order corrections for the SM-like Higgs boson mass and the trilinear Higgs self-couplings in the Next-to-Minimal Supersymmetric extension of the Standard Model (NMSSM) with Inverse Seesaw Mechanism are significant and highly correlated. We present here the full one-loop corrections to the trilinear Higgs self-couplings supplemented by the dominant top-Yukawa and strong coupling induced two-loop corrections from our previous calculations in the complex NMSSM. These corrections are performed consistently with the corresponding Higgs boson mass corrections. We discuss in detail the new effects from the extended neutrino and sneutrino sectors on both the trilinear Higgs self-couplings and the SM-like Higgs boson mass. When compared to the case of the NMSSM without Inverse Seesaw Mechanism, the new effects can be up to 10\% for the effective SM-like trilinear Higgs self-couplings, and up to 4.5\% for the SM-like Higgs boson mass for valid parameter points, i.e. points satisfying the Higgs data, the neutrino data, the constraints from the charged lepton flavor-violating decays, and the new physics constraints from the oblique parameters $S, T, U$. The new corrections are also included in the Higgs-to-Higgs decays for the heavy Higgs states and implemented in the new version of the Fortran code NMSSMCALC-nuSS.

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arXiv2025

Effects of bottom quark induced processes on polarized $W^+W^-$ production at the LHC at NLO

In this report we discuss the definition of the polarized cross sections of the inclusive $W^+W^-$ production at the LHC. Results at the level of next-to-leading order (NLO) QCD+EW accuracy, published in our recent paper, are presented to highlight the effects of bottom-quark induced processes. Compared to the unpolarized case, the bottom-induced effects after the subtraction of the on-shell top-quark contribution are more sizable for the doubly-longitudinal polarization.

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arXiv2025

Polarized $W^+W^-$ pairs at the LHC: Effects from bottom-quark induced processes at NLO QCD+EW

We investigate the effects of the bottom-quark induced processes on the doubly polarized cross sections of $W^+W^-$ pair production at the LHC. The method to extract the on-shell single-top contribution is provided. Results for phenomenological and experimental analyses are given at next-to-leading order (NLO) QCD+EW accuracy, with the leading contribution from the gluon-gluon and photon-photon fusion included. We found that the contribution of the bottom-quark induced processes, after the subtraction of the on-shell $tW$ channel, is largest for the doubly longitudinal polarization. At the integrated cross section level, using a fiducial ATLAS cut with a jet veto, the effect is $9\%$ compared to the NLO value of the light-quark contribution. It increases to $13\%$ after removing the jet veto. A bound of the $tW$ interference is calculated for various kinematic distributions, showing that this interference effect is, in general, smaller for the no jet veto case. Relevant scale uncertainties are calculated to help us decide on the importance of this interference.

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arXiv2025

Joint polarizations of W pair production at the LHC at NLO QCD+EW accuracy

In this contribution, we present new results of next-to-leading order (NLO) electroweak corrections to the doubly polarized $W^+W^-$ production cross sections at the LHC, via the full leptonic final state. This calculation has been recently achieved independently by two groups: one in Germany and our group in Vietnam. A comparison of the two results will be presented. We include also the NLO QCD corrections in the numerical analysis since they are dominant and therefore important for comparison with experimental results. New results of integrated cross section for future proton-proton colliders with $\sqrt{s}=$ $27$ TeV, $50$ TeV, $100$ TeV are provided. Moreover, a detailed explanation of the $σ_\text{TT}>σ_\text{LT}>σ_\text{LL}$ hierarchy based on the Born approximation is given.

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arXiv2025

Higgs Mass Predictions in the CP-Violating High-Scale NMSSM

In a supersymmetric theory, large mass hierarchies can lead to large uncertainties in fixed-order calculations of the Standard Model (SM)-like Higgs mass. A reliable prediction is then obtained by performing the calculation in an effective field theory (EFT) framework, involving a matching to the full supersymmetric theory at the high scale to include contributions from the heavy particles, and a subsequent renormalisation-group running down to the low scale. We report on the prediction of the SM-like Higgs mass within the CP-violating Next-to-Minimal Supersymmetric extension of the SM (NMSSM) in a scenario where all non-SM particles feature TeV-scale masses. The matching conditions are calculated at full one-loop order using two approaches. These are the matching of the quartic Higgs couplings as well as of the SM-like Higgs pole masses of the low- and high-scale theory. A comparison between the two methods allows us to estimate the size of terms suppressed by the heavy mass scale that are neglected in a pure EFT calculation as given by the quartic-coupling matching. Furthermore, we study the different sources of uncertainty which enter our calculation as well as the effect of CP-violating phases on the Higgs mass prediction. The matching calculation is implemented in a new version of the public program package NMSSMCALC.

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arXiv2024

NLO electroweak corrections to doubly-polarized $W^+W^-$ production at the LHC

We present new results of next-to-leading order (NLO) electroweak corrections to doubly-polarized cross sections of $W^+W^-$ production at the LHC. The calculation is performed for the leptonic final state of $e^+μ_e μ^- \barν_μ$ using the double-pole approximation in the diboson center-of-mass frame. NLO QCD corrections and subleading contributions from the $gg$, $b\bar{b}$, $γγ$ induced processes are taken into account in the numerical results. We found that NLO EW corrections are small for angular distributions but can reach tens of percent for transverse momentum distributions at high energies, e.g. reaching $-40\%$ at $p_{T,e}\approx 300$ GeV. In these high $p_T$ regions, EW corrections are largest for the doubly-transverse mode.

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arXiv2023

The ${\cal O}(α_t+α_λ+α_κ)^2$ Correction to the $ρ$ Parameter and its Effect on the W Boson Mass Calculation in the Complex NMSSM

We present the prediction of the electroweak $ρ$ parameter and the $W$ boson mass in the CP-violating Next-to-Minimal Supersymmetric extension of the Standard Model (NMSSM) at the two-loop order. The $ρ$ parameter is calculated at the full one-loop and leading and sub-leading two-loop order $\mathcal{O}(α+ α_tα_s + \left(α_t+α_λ+α_κ\right)^2)$. The new $Δρ$ prediction is incorporated into a prediction of $M_W$ via a full supersymmetric (SUSY) one-loop calculation of $Δr$. Furthermore, we include all known state-of-the-art SM higher-order corrections to $Δr$. By comparing results for $Δρ$ obtained using on-shell (OS) and $\overline{\mathrm{DR}}$ renormalization conditions in the top/stop sector, we find that the scheme uncertainty is reduced at one-loop order by 55%, at two-loop $\mathcal{O}(α_sα_t)$ by 22%, and at two-loop $\mathcal{O}(α_t+α_κ+α_λ)^2$ by 16%, respectively. The influence of the two-loop results on the $M_W$ mass prediction is found to be sub-leading. The new calculation is made public in the computer program $\mathrm{\tt NMSSMCALC}$. We perform an extensive comparison in the $W$-mass, Higgs boson mass and the muon anomalous magnetic moment prediction between our calculation and three other publicly available tools and find very good agreement provided that the input parameters and renormalization scales are treated in the same way. Finally, we study the impact of the CP-violating phases on the $W$-mass prediction which is found to be smaller than the overall size of the SUSY corrections.

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arXiv2023

Enhancing the doubly-longitudinal polarization in WZ production at the LHC

We present new results for the theoretical prediction of doubly-polarized cross sections of $WZ$ events at the LHC using leptonic decays. Compared to the previous studies, two new kinematic cuts are considered. These cuts are designed to enhance the doubly-longitudinal (LL) polarization and, at the same time, study the Radiation Amplitude Zero effect. We found a new cut on the rapidity separation between the $Z$ boson and the electron from the $W$ decay which makes the LL fraction largest, namely $|Δy_{Z,e}| < 0.5$. This result is obtained at the next-to-leading order in the strong and electroweak couplings.

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arXiv2022

The Trilinear Higgs Self-Couplings at ${\cal O}(α_t^2)$ in the CP-Violating NMSSM

In supersymmetric theories the Higgs boson masses are derived quantities where higher-order corrections have to be included in order to match the measured Higgs mass value at the precision of current experiments. Closely related through the Higgs potential are the Higgs self-interactions. In addition, the measurement of the trilinear Higgs self-coupling provides the first step towards the reconstruction of the Higgs potential and the experimental verification of the Higgs mechanism sui generis. In this paper, we advance our prediction of the trilinear Higgs self-couplings in the CP-violating Next-to-Minimal Supersymmetric extension of the SM (NMSSM). We provide the ${\cal O}(α_t^2)$ corrections in the gaugeless limit at vanishing external momenta. The higher-order corrections turn out to be larger than the corresponding mass corrections but show the expected perturbative convergence. The inclusion of the loop-corrected effective trilinear Higgs self-coupling in gluon fusion into Higgs pairs and the estimate of the theoretical uncertainty due to missing higher-order corrections indicate that the missing electroweak higher-order corrections may be significant.

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arXiv2022

Doubly-polarized $WZ$ hadronic production at NLO QCD+EW: Calculation method and further results

The doubly-polarized production of $W^\pm Z$ pairs at the Large Hadron Collider (LHC) is presented at next-to-leading order (NLO) accuracy both for the electroweak (EW) and QCD corrections, including a detailed description of the calculational method using the double-pole approximation. Numerical results at the 13 TeV LHC are presented in particular for the $W^- Z$ case in the $e^-\barν_e μ^+μ^-$ channel using ATLAS fiducial cuts and for polarized distributions defined in the $WZ$ center-of-mass system. The NLO EW corrections relative to the NLO QCD predictions are found to be smaller than $5\%$ in most kinematic distributions, but can reach the level of $10\%$ in some distributions such as lepton transverse momentum distributions or rapidity separation between the electron and the $Z$ boson. EW corrections are not uniform for different polarizations. A comparison between the new ATLAS measurement of polarization fractions to our theoretical prediction is presented.

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arXiv2022

Leptonic Anomalous Magnetic and Electric Dipole Moments in the CP-violating NMSSM with and without Inverse Seesaw Mechanism

The new results on the muon anomalous magnetic moment (AMM) published by Fermilab in 2021, did not lead to a reduction of its long-pending deviation from the Standard Model (SM) value by more than 4$σ$. The explanation of this discrepancy by adding new particles to the theory puts many new physics models under tension when combined with the null results of the LHC direct searches for new particles. In this paper, we investigate the CP-violating Next-to-Minimal Supersymmetric extension of the SM (NMSSM) with and without an inverse seesaw mechanism. We compute the one-loop supersymmetric contributions to the AMM and the two-loop Barr-Zee-type diagrams with effective Higgs couplings to photons for the leptonic electric dipole moments (EDMs). The effects of the extended (s)neutrino sector on the muon AMM and on the mass of the SM-like Higgs boson can be significant. Complex phases can have an important impact on the AMM. On the other hand, the stringent limits from the EDMs on the complex phases have to be taken into account. Our calculations have been implemented in the Fortran codes NMSSMCALC and NMSSMCALC-nuSS which are publicly available. Besides the leptonic AMMs and EDMs, these programs can compute the Higgs boson masses and mixings, together with Higgs boson decay widths and branching ratios taking into account the mostup-to-date higher-order corrections in the NMSSM with and without inverse seesaw mechanism.

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arXiv2021

Loop-corrected Higgs Masses in the NMSSM with Inverse Seesaw Mechanism

In this study, we work in the framework of the Next-to-Minimal extension of the Standard Model (NMSSM) extended by six singlet leptonic superfields. Through the mixing with the three doublet leptonic superfields, the non-zero tiny neutrino masses can be generated through the inverse seesaw mechanism. While $R$-parity is conserved in this model lepton number is explicitly violated. We quantify the impact of the extended neutrino sector on the NMSSM Higgs sector by computing the complete one-loop corrections with full momentum dependence to the Higgs boson masses in a mixed on-shell-$\overline{\mbox{DR}}$ renormalization scheme, with and without the inclusion of CP violation. The results are consistently combined with the dominant two-loop corrections at ${\cal O}(α_t(α_s+α_t))$ to improve the predictions for the Higgs mixing and the loop-corrected masses. In our numerical study we include the constraints from the Higgs data, the neutrino oscillation data, the charged lepton flavor-violating decays $l_i \to l_j + γ$, and the new physics constraints from the oblique parameters $S,T,U$. We present in this context the one-loop decay width for $l_i \to l_j + γ$. The loop-corrected Higgs boson masses are included in the Fortran code NMSSMCALC-nuSS.

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arXiv2021

Two-Loop ${\cal O}((α_t+α_λ+α_κ)^2)$ Corrections to the Higgs Boson Masses in the CP-Violating NMSSM

We present our computation of the ${\cal O}((α_t+α_λ+α_κ)^2)$ two-loop corrections to the Higgs boson masses of the CP-violating Next-to-Minimal Supersymmetric Standard Model (NMSSM) using the Feynman-diagrammatic approach in the gaugeless limit at vanishing external momentum. We choose a mixed $\overline{\mbox{DR}}$-on-shell (OS) renormalisation scheme for the Higgs sector and apply both $\overline{\mbox{DR}}$ and OS renormalisation in the top/stop sector. For the treatment of the infrared divergences we apply and compare three different regularisation methods: the introduction of a regulator mass, the application of a small momentum expansion, and the inclusion of the full momentum dependence. Our new corrections have been implemented in the Fortran code NMSSMCALC that computes the Higgs mass spectrum of the CP-conserving and CP-violating NMSSM as well as the Higgs boson decays including the state-of-the-art higher-order corrections. Our numerical analysis shows that the newly computed corrections increase with rising $λ$ and $κ$, remaining overall below about 3\% compared to our previously computed ${\cal O}(α_t(α_t+α_s))$ corrections, in the region compatible with perturbativity below the GUT scale. The renormalisation scheme and scale dependence is of typical two-loop order. The impact of the CP-violating phases in the new corrections is small. We furthermore show that the Goldstone Boson Catastrophe due to the infrared divergences can be treated in a numerically efficient way by introducing a regulator mass that approximates the momentum-dependent results best for squared mass values in the permille range of the squared renormalisation scale. Our results mark another step forward in the program of increasing the precision in the NMSSM Higgs boson observables.

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arXiv2021

Precision Predictions for Charged Higgs Boson Decays in the Real and Complex NMSSM

We present the full next-to-leading order (NLO) supersymmetric (SUSY) electroweak and SUSY-QCD corrections to the decay widths of the charged Higgs boson decays into on-shell final states in the framework of the CP-conserving and CP-violating Next-to-Minimal Supersymmetric Model (NMSSM). The newly calculated corrections have been implemented in the code NMSSMCALCEW. In these proceedings, we discuss the impact of the NLO corrections on the charged Higgs boson branching ratios in a wide range of the parameter space that is still compatible with the experimental constraints. We also investigate the effect of CP violation in these corrections.

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arXiv2020

One-loop Corrections to the Two-Body Decays of the Charged Higgs Bosons in the Real and Complex NMSSM

We evaluate the full next-to-leading order supersymmetric (SUSY) electroweak and SUSY-QCD corrections to the on-shell two-body decays of the charged Higgs bosons in the framework of the CP-conserving and CP-violating Next-to-Minimal Supersymmetric extension of the Standard Model (NMSSM). Our corrections are implemented in the code NMSSMCALCEW in order to compute the branching ratios of the charged Higgs boson where we also take into account the state-of-the-art QCD corrections already included in the code. We investigate the impact of the NLO corrections for each decay mode in a wide range of the parameter space that is allowed by the theoretical and experimental constraints. The new version of NMSSMCALCEW is made publicly available.

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