arXiv subjects

Santiago Lopez Portillo Chavez

Publications and source records attributed to Santiago Lopez Portillo Chavez.

5 recordsLinked to original sources

arXiv2026

The cleanest of them all: NLO electroweak corrections to vector-boson scattering into doubly polarised ZZ pairs at the LHC

We present the first calculation of the next-to-leading-order electroweak corrections to vector-boson scattering into doubly polarised Z bosons at the LHC in the fully leptonic decay channel. The production and decay of the two polarised Z bosons are consistently modelled in the double-pole approximation, separating polarisation states at the amplitude level and including factorisable real and virtual electroweak corrections. Doubly polarised and unpolarised signals are investigated and confronted with off-shell results. A broad analysis, including results at integrated and differential level, is carried out in a realistic, CMS-inspired fiducial setup. Our study paves the way to upcoming analyses with LHC Run-3 and High-Luminosity data as well as to further phenomenological investigations.

hep-ph↗

arXiv2026

NLO QCD and EW corrections to semileptonic vector-boson scattering at the LHC

Vector-boson scattering with semileptonic final states has recently been measured at the LHC, and future experiments are expected to further increase the precision of its measurement, calling for adequate theoretical predictions. In this work, we present a calculation of the NLO QCD and electroweak corrections to the process $\text{p}\text{p} \to \ell^+ ν_\ell + 4\text{j}$ in two different fiducial regions relevant for vector-boson scattering. In a fully off-shell calculation, we provide results for the leading electroweak contribution of $\mathcal{O}\left(α^6\right)$ and the corresponding corrections of $\mathcal{O}\left(α^7\right)$ and $\mathcal{O}\left(α_\text{s} α^6\right)$ for fiducial cross sections and a selection of differential distributions.

hep-ph↗

arXiv2025

Electroweak $W^+ W^+$ production in association with three jets at NLO QCD matched with parton shower

We present a next-to-leading order QCD calculation for the electroweak production of a pair of same-sign weak gauge bosons in association with three jets in the region dominated by vector boson scattering, and its matching with parton-shower programs according to the POWHEG formalism. Our calculation allows for an accurate description of jet observables crucial for the optimization of experimental analyses of vector boson scattering processes. We find QCD corrections and parton-shower effects moderate in size for inclusive quantities and distributions of the tagging jets. A larger impact of these corrections is observed for subleading jets.

hep-ph↗

arXiv2024

NLO corrections to triple vector-boson production in final states with three charged leptons and two jets

Tri-boson production together with vector-boson scattering is a privileged channel to study the electroweak structure of the Standard Model. Upcoming LHC running stages will allow to measure these processes at unprecedented accuracy and for all possible final states, which requires to push theory predictions to still unexplored frontiers. In this work we present the first calculation for the process ${\rm p}{\rm p}\toμ^+μ^-{\rm e}^+ν_{\rm e}\,{\rm j}\,{\rm j}$ at the LHC in a tri-boson phase space. We evaluate the three LO contributions, namely the $\mathcal{O}(α^6)$, which contains the genuine tri-boson signature, along with the $\mathcal{O}(α_{\rm s}α^5)$ and $\mathcal{O}(α_{\rm s}^2α^4)$, and the two $\mathcal{O}(α^7)$ and $\mathcal{O}(α_{\rm s}α^6)$ NLO corrections. The calculation is based on full Standard-Model matrix elements, including all resonant and non-resonant terms, complete spin correlations and interference effects. Integrated and differential cross sections are presented for a fiducial region inspired by High Luminosity LHC prospect studies. We find electroweak corrections of $-14\%$ for the fiducial cross section, almost twice as large as for other tri-boson processes.

hep-ph↗

arXiv2021

Hadronic production of top-quark pairs in association with a pair of leptons in the POWHEG BOX framework

We present an implementation of $t\bar t \ell^+\ell^-$ ($\ell=e,μ$) hadronic production at next-to-leading order in QCD matched to parton-shower event generators in the POWHEG BOX framework. The program we developed includes all leading-order contributions of order $α_s^2α^2$ for the specified final state, as well as the corresponding first-order QCD corrections. Decays of the top quarks have been simulated retaining spin-correlations in all tree-level matrix elements. We consider the case of the Large Hadron Collider at $\sqrt{s}=13$ TeV and compare results for $t\bar t \ell^+\ell^-$ production in the fiducial volume where the invariant mass of the lepton pairs is centered around the $Z$-boson mass to corresponding predictions for $t\bar{t}Z$ on-shell production with $Z\rightarrow \ell^+\ell^-$. We find that off-shell effects in $t\bar t \ell^+\ell^-$ are in general small at the level of the total cross section, but can decrease the tail of the leptons' transverse momentum distributions by 10-20% and, in these regions, they are visible beyond the scale uncertainty due to renormalization and factorization scale variation. Moreover, we find that accounting for top-quark decays in the narrow-width approximation with tree-level spin correlations also gives origin to 10-20% effects in specific regions of the kinematic distributions of the $t\bar t \ell^+\ell^-$ decayed final state.

hep-ph↗