arXiv subjects

Simone Tentori

Publications and source records attributed to Simone Tentori.

9 recordsLinked to original sources

arXiv2026

Constraining the real singlet extension of the Standard Model: implications for vacuum stability

Amongst the simplest extensions of the Standard Model is the addition of a real singlet scalar field with profound phenomenological consequences. The singlet can catalyze a strong first-order electroweak phase transition, necessary for successful electroweak baryogenesis. Furthermore, the current prediction of a metastable Higgs vacuum can be lifted towards absolute stability. While current data mainly constrain the scalar mixing angle, future measurements of the Higgs self-coupling and direct searches for additional scalar states will probe much larger parts of the viable parameter space. We report on a combined study of theoretical and experimental constraints on the real singlet extension, highlighting here in particular its implications for vacuum stability.

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arXiv2026

Constraining the real scalar singlet extension of the SM

The real scalar singlet extension of the standard model provides a minimal framework in which the Higgs sector can realise a strong first-order electroweak phase transition and improve the stability of the electroweak vacuum. We combine the electroweak phase transition and high-scale vacuum stability with current and projected collider probes, including precision Higgs measurements, the Higgs trilinear coupling, EWPO and resonant searches for a heavy singlet-like scalar in $ZZ$ and di-Higgs final states. Focusing on a singlet heavier than the standard model Higgs, we find that there is parameter space compatible with a strong first-order electroweak phase transition for singlet-like scalar masses up to nearly 1 TeV. Deviations in the Higgs self-coupling can be larger than those in the Higgs--$Z$ coupling, making Higgs-potential measurements a key probe. We find that the HL-LHC will test a large fraction of the parameter space, while the FCC will provide ultimate discovery and model-discrimination capabilities.

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arXiv2026

New Physics Reach through Precision at Future Colliders: a Multi-Pronged Approach

We present projections for the sensitivity of future high-energy colliders to new physics through precision measurements of the Standard Model (SM) interactions, focusing on near-term electron-positron facilities: FCC-ee, LEP3, and the Linear Collider Facility. We interpret these projections in three complementary frameworks: Higgs coupling modifiers, effective Higgs and electroweak couplings, and global SMEFT fits. The SMEFT analysis includes renormalisation-group evolution, linear/quadratic contributions, and NLO corrections to EFT cross sections where available. By matching the EFT to UV-complete models, we also quantify the sensitivity of future colliders to representative benchmark scenarios, including composite Higgs models and single-particle SM extensions. In parallel, we release an updated version of the open-source SMEFiT framework, enabling the results presented here to be fully reproduced, extended, and customised.

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arXiv2024

Virtual corrections to top-pair production from new physics

New physics and SM parameters can be studied and constrained by looking at the modifications to top-pair differential kinematical distributions due to off-shell effects. I present here three case studies: the determination of the Higgs couplings to the top-quark, a search for generic BSM scalar and pseudoscalar states, and a search for Axion Like Particles (ALP). The corresponding models have been implemented in the $\texttt{UFO}$ format to allow automatic computations within MadGraph5_aMC@NLO.

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arXiv2024

Top-quark pair production as a probe of light top-philic scalars and anomalous Higgs interactions

We compute the effects due to the virtual exchange (or the soft emission) of a scalar particle with generic couplings to the top quark in $t\bar t$ pair production at the LHC. We apply the results to two cases of interest, extending and completing previous studies. First, we consider the indirect search for light ($m_S<2 m_t$) top-philic scalars with CP-even and/or CP-odd interactions. Second, we investigate how to set constraints on anomalous Yukawa couplings of the Higgs boson to the top quark. Our results show that the current precision of experimental data together with the accuracy of the SM predictions make such indirect determinations a powerful probe for new physics.

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arXiv2024

Quantum tops at circular lepton colliders

We study the quantum properties of top quark pairs in lepton colliders with unpolarised beams, including spin correlations, entanglement, and violation of Bell inequalities. We present analytical results in the SM and in the SMEFT and discuss several practical aspects, like the choice of quantization axes and $t \bar t$ threshold effects. We also note a correspondence between parity symmetry and entanglement. We find that quantum observables exhibit a rich phenomenology in the SM, and can also provide additional leverage in detecting new physics residing at higher scales.

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arXiv2024

Quantum detection of new physics in top-quark pair production at the LHC

The recent observation of entanglement between top and anti-top quarks at the LHC opens the way to interpreting collider data with quantum information tools. In this work we investigate the relevance of quantum observables in searches of new physics. To this aim, we study spin correlations of top/anti-top pairs originating from various intermediate resonances, and compare the discovery reach of quantum observables compared to classical ones. We find that they provide complementary information and, in several notable cases, also the additional leverage necessary to detect new effects.

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arXiv2024

Top-philic ALP phenomenology at the LHC

I present an exploration of the LHC phenomenology of the so-called top-philic ALP in the mass range between tens and hundreds of GeV. Searches through resonant production, such as ALP production in association with a $t\bar t$ pair are shown to be complementary to precision measurements of $t \bar t$ and $t\bar t t \bar t$ final states. The case where the ALP decays invisibly is also considered looking at final states with missing energy signatures.

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arXiv2023

Top-philic ALP phenomenology at the LHC: the elusive mass-window

We study the LHC phenomenology of an Axion Like Particle (ALP) that couples only derivatively with the top quark at tree level. We inspect the radiatively induced couplings with the SM fermions and (gauge) bosons and the associated production and decay mechanisms of the ALP. We focus on the most challenging mass window that remains open for a top-philic ALP, i.e., the range between tens and hundreds of GeV. Not only ALP production processes but also virtual ALP contributions to final states with top quarks are considered in detail. We show how searches through resonant production, such as ALP production in association with a $t\bar t$ pair, are complementary to precision measurements of $t \bar t$ and $t\bar t t \bar t$ final states, the latter being competitive or even more powerful for a top-philic ALP in this mass window. Finally, we explore the scenario where the top-philic ALP acts as a mediator to a dark-matter sector, resulting in missing energy signatures at the LHC. We find that the LHC constraints from $t \bar t$, $t\bar t t \bar t$ and ALP + jet production, together with those from $t \bar t$ + ALP production, can already exclude a large fraction of the parameter space leading to the correct relic abundance.

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