The tiny (g-2) muon wobble from small-μ supersymmetry

A new measurement of the muon anomalous magnetic moment, gμ− 2, has been reported by the Fermilab Muon g-2 collaboration and shows a 4.2 σ departure from the most precise and reliable calculation of this quantity in the Standard Model. Assuming that this discrepancy is due to new physics, we concentrate on a simple supersymmetric model that also provides a dark matter explanation in a previously unexplored region of supersymmetric parameter space. Such interesting region can realize a Bino-like dark matter candidate compatible with all current direct detection constraints for small to moderate values of the Higgsino mass parameter |μ|. This in turn would imply the existence of light additional Higgs bosons and Higgsino particles within reach of the high-luminosity LHC and future colliders. We provide benchmark scenarios that will be tested in the next generation of direct dark matter experiments and at the LHC.

Gravitational waves generation in turbulent hypermagnetic fields before the electroweak phase transition

We study the production of relic gravitational waves (GWs) in turbulent hypermagnetic fields (HMFs) in the symmetric phase of the early universe before the electroweak phase transition (EWPT). The noise of HMFs is modeled by the analog of the magnetic hydrodynamics turbulence. The evolution of HMFs is driven by the analogs of the chiral magnetic effect and the Adler anomalies in the presence of the nonzero asymmetries of leptons and Higgs bosons. We track the evolution of the energy density of GWs from 10 TeV down to EWPT and analyze its dependence on the parameters of the system. We also discuss the possibility to observe the predicted GW background by the current GW detectors.

Collider Searches for Dark Matter through the Higgs Lens

Despite the fact that dark matter constitutes one of the cornerstones of the standard cosmological paradigm, its existence has so far only been inferred from astronomical observations, and its microscopic nature remains elusive. Theoretical arguments suggest that dark matter might be connected to the symmetry-breaking mechanism of the electroweak interactions or of other symmetries extending the Standard Model of particle physics. The resulting Higgs bosons, including the 125 GeV spin-0 particle discovered recently at the Large Hadron Collider, therefore represent a unique tool to search for dark matter candidates at collider experiments. This article reviews some of the relevant theoretical models as well as the results from the searches for dark matter in signatures that involve a Higgs-like particle at the Large Hadron Collider.

Search for chargino–neutralino pair production in final states with three leptons and missing transverse momentum in $$\sqrt{s} = 13$$ TeV pp collisions with the ATLAS detector

A search for chargino–neutralino pair production in three-lepton final states with missing transverse momentum is presented. The study is based on a dataset of $$\sqrt{s} = 13$$ s = 13 TeV pp collisions recorded with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 139 $$\hbox {fb}^{-1}$$ fb - 1 . No significant excess relative to the Standard Model predictions is found in data. The results are interpreted in simplified models of supersymmetry, and statistically combined with results from a previous ATLAS search for compressed spectra in two-lepton final states. Various scenarios for the production and decay of charginos ($${\tilde{\chi }}^\pm _1$$ χ ~ 1 ± ) and neutralinos ($${\tilde{\chi }}^0_2$$ χ ~ 2 0 ) are considered. For pure higgsino $${\tilde{\chi }}^\pm _1{\tilde{\chi }}^0_2$$ χ ~ 1 ± χ ~ 2 0 pair-production scenarios, exclusion limits at 95% confidence level are set on $${\tilde{\chi }}^0_2$$ χ ~ 2 0 masses up to 210 GeV. Limits are also set for pure wino $${\tilde{\chi }}^\pm _1{\tilde{\chi }}^0_2$$ χ ~ 1 ± χ ~ 2 0 pair production, on $${\tilde{\chi }}^0_2$$ χ ~ 2 0 masses up to 640 GeV for decays via on-shell W and Z bosons, up to 300 GeV for decays via off-shell W and Z bosons, and up to 190 GeV for decays via W and Standard Model Higgs bosons.

Exploration of Extended Higgs Sectors with Run-2 Proton–Proton Collision Data at the LHC

One doublet of complex scalar fields is the minimal content of the Higgs sector in order to achieve spontaneous electroweak symmetry breaking and, in turn, to generate the masses of fundamental particles in the Standard Model. However, several theories beyond the Standard Model predict a nonminimal Higgs sector and introduce additional singlets, doublets or even higher-order weak isospin representations, thereby yielding additional Higgs bosons. With its high proton–proton collision energy (13 TeV during Run-2), the Large Hadron Collider opens a new window towards the exploration of extended Higgs sectors. This review article summarises the current state-of-the-art experimental results recently obtained in searches for new neutral and charged Higgs bosons with a partial or full Run-2 dataset.

A three Higgs doublet model with symmetry-suppressed flavour changing neutral currents

We construct a three-Higgs doublet model with a flavour non-universal U(1) × ℤ2 symmetry. That symmetry induces suppressed flavour-changing interactions mediated by neutral scalars. New scalars with masses below the TeV scale can still successfully negotiate the constraints arising from flavour data. Such a model can thus encourage direct searches for extra Higgs bosons in the future collider experiments, and includes a non-trivial flavour structure.

Naturalness implications within the two-real-scalar-singlet beyond the SM

The aim of this study is to investigate the quadratic divergences using dimensional regularization within the context of the Standard Model (SM) extended by two real scalar singlets (TRSM). This extension provides three neutral scalar fields that mix, after developing its VEVs, leading to three CP-even Higgs bosons, namely, $$h_1$$ h 1 , $$h_2$$ h 2 and $$h_3$$ h 3 , which would offer a wide phenomenology at the Large Hadron Collider (LHC), as reported recently. Furthermore, to fulfill the Veltman conditions for those three fields, we concentrate on the one-loop level ($$d_L=2$$ d L = 2 ) of dimensional regularization calculations, assuming $$R_{\xi }$$ R ξ Feynman–’t Hooft gauge-invariant, $$\xi =1$$ ξ = 1 . We show that the divergence cancellation could take place in the framework of the TRSM for the SM-like Higgs boson predicting a stringent constraint on the space parameters as well as the new physics (NP) scale, and yet remain consistent with current experimental measurements at 13 TeV.