Abstract: We present an experimentally practical method to reveal Einstein-Podolsky-Rosen (EPR) steering in non-Gaussian spin states by exploiting a connection to quantum metrology. Our criterion is based on the quantum Fisher information, and uses bounds derived from generalized spin-squeezing parameters that involve measurements of higher-order moments. This leads us to introduce the concept of conditional spin-squeezing parameters, which quantify the metrological advantage provided by conditional states, as well as detect the presence of an EPR paradox.

Abstract: We explore the complementarity of direct detection (DD) and spallation source (SS) experiments for the study of sterile neutrino physics. We focus on the sterile baryonic neutrino model: an extension of the Standard Model that introduces a massive sterile neutrino with couplings to the quark sector via a new gauge boson. In this scenario, the inelastic scattering of an active neutrino with the target material in both DD and SS experiments gives rise to a characteristic nuclear recoil energy spectrum that can allow for the reconstruction of the neutrino mass in the event of a positive detection. We first derive new bounds on this model based on the data from the COHERENT collaboration on CsI and LAr targets, which we find do not yet probe new areas of the parameter space. We then assess how well future SS experiments will be able to measure the sterile neutrino mass and mixings, showing that masses in the range similar to 15 – 50 MeV can be reconstructed. We show that there is a degeneracy in the measurement of the sterile neutrino mixing that substantially affects the reconstruction of parameters for masses of the order of 40 MeV. Thanks to their lower energy threshold and sensitivity to the solar tau neutrino flux, DD experiments allow us to partially lift the degeneracy in the sterile neutrino mixings and considerably improve its mass reconstruction down to 9 MeV. Our results demonstrate the excellent complementarity between DD and SS experiments in measuring the sterile neutrino mass and highlight the power of DD experiments in searching for new physics in the neutrino sector.

Abstract: Searches for the exclusive decays of the Higgs boson to an omega meson and a photon or a K* meson and a photon can probe flavour-conserving and flavour-violating Higgs boson couplings to light quarks, respectively. Searches for these decays, along with the analogous Z boson decay to an omega meson and a photon, are performed with a pp collision data sample corresponding to integrated luminosities of up to 134 fb(-1) collected at root s = 13 TeV with the ATLAS detector at the CERN Large Hadron Collider. The obtained 95% confidence-level upper limits on the respective branching fractions are B(H -> omega gamma) < 5.5 x 10(-4), B(H -> K*gamma) < 2.2 x 10(-4) and B(Z -> omega gamma) < 3.9 x 10(-6). The limits for H -> omega gamma and Z -> omega gamma) are 370 times and 140 times the Standard Model expected values, respectively. The result for Z -> omega gamma corresponds to a two-orders-of-magnitude improvement over the limit obtained by the DELPHI experiment at LEP.

Abstract: A measurement of the CP-violating observables from B -> (DK +/-)-K-* and B-+/- -> D-*pi(+/-) decays is presented, where D-*(D) is an admixture of D-*0 and D-0 (D-0 and (0)) states and is reconstructed through the decay chains D-*-> D pi(0)/gamma and D -> KS0 pi+pi-/KS0K+K-. The measurement is performed by analysing the signal yield variation across the D decay phase space and is independent of any amplitude model. The data sample used was collected by the LHCb experiment in proton-proton collisions and corresponds to a total integrated luminosity of 9 fb(-1) at centre-of-mass energies of 7, 8 and 13 TeV. The CKM angle gamma is determined to be (69(-14)(+13))degrees using the measured CP-violating observables. The hadronic parameters r(B)(D)*(K +/-),r(B)(D)*(pi +/-),delta(D)(B)*(K +/-),delta(D)(B)*(pi +/-), which are the ratios and strong phase differences between favoured and suppressed B-+/- decays, are also reported.

Abstract: A search for supersymmetry targeting the direct production of winos and higgsinos is conducted in final states with either two leptons (e or mu) with the same electric charge, or three leptons. The analysis uses 139 fb(-1) of pp collision data at root s = 13TeV collected with the ATLAS detector during Run 2 of the Large Hadron Collider. No significant excess over the Standard Model expectation is observed. Simplified and complete models with and without R-parity conservation are considered. In topologies with intermediate states including either Wh or WZ pairs, wino masses up to 525 GeV and 250 GeV are excluded, respectively, for a bino of vanishing mass. Higgsino masses smaller than 440 GeV are excluded in a natural R-parity-violating model with bilinear terms. Upper limits on the production cross section of generic events beyond the Standard Model as low as 40 ab are obtained in signal regions optimised for these models and also for an R-parity-violating scenario with baryon-number-violating higgsino decays into top quarks and jets. The analysis significantly improves sensitivity to supersymmetric models and other processes beyond the Standard Model that may contribute to the considered final states.