Using 116.1 fb(-1) of data collected by the BABAR detector, we present an analysis of xi(c)(0) production in B decays and from the cc continuum, with the xi(c)(0) decaying into omega- K+ and xi- pi+ final states. We measure the ratio of branching fractions B(xi(c)(0) --> omega- K+)/B(xi(c)(0) --> xi- pi+) spectrum is measured on and 40 MeV below the upsilon(4S) resonance. From these spectra the branching fraction product B(B --> xi(c)(0)X) x B(xi(c)(0) --> xi- pi+) is measured to be (2.11 +/- 0.19 +/- 0.25) x 10(-4), and the cross-section product sigma(e+ e- --> xi(c)(0)X) x B(xi(c)(0) --> xi- pi+) from the continuum is measured to be (388 +/- 39 +/- 41) fb at a center-of-mass energy of 10.58 GeV.

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The unprecedented volume and rate of transient events that will be discovered by the Large Synoptic Survey Telescope (LSST) demands that the astronomical community update its followup paradigm. Alert-brokers -automated software system to sift through, characterize, annotate and prioritize events for followup -will be critical tools for managing alert streams in the LSST era. The Arizona-NOAO Temporal Analysis and Response to Events System (ANTARES) is one such broker. In this work, we develop a machine learning pipeline to characterize and classify variable and transient sources only using the available multiband optical photometry. We describe three illustrative stages of the pipeline, serving the three goals of early, intermediate and retrospective classification of alerts. The first takes the form of variable vs transient categorization, the second, a multi-class typing of the combined variable and transient dataset, and the third, a purity-driven subtyping of a transient class. While several similar algorithms have proven themselves in simulations, we validate their performance on real observations for the first time. We quantitatively evaluate our pipeline on sparse, unevenly sampled, heteroskedastic data from various existing observational campaigns, and demonstrate very competitive classification performance. We describe our progress towards adapting the pipeline developed in this work into a real-time broker working on live alert streams from time-domain surveys.

Search for charged Higgs bosons decaying viaH ± → τ ± ν τ in the τ+jets and τ+lepton final states with 36 fb −1 of p p collision data recorded at √ s = 13 TeV with the ATLAS experimentThe ATLAS Collaboration Charged Higgs bosons produced either in top-quark decays or in association with a topquark, subsequently decaying via H ± → τ ± ν τ , are searched for in 36.1 fb −1 of proton-proton collision data at √ s = 13 TeV recorded with the ATLAS detector. Depending on whether the top-quark produced together with H ± decays hadronically or leptonically, the search targets τ+jets and τ+lepton final states, in both cases with a hadronically decaying τ-lepton. No evidence of a charged Higgs boson is found. For the mass range of m H ± = 90-2000 GeV, upper limits at the 95% confidence level are set on the production cross-section of the charged Higgs boson times the branching fraction B(H ± → τ ± ν τ ) in the range 4.2-0.0025 pb. In the mass range 90-160 GeV, assuming the Standard Model cross-section for tt production, this corresponds to upper limits between 0.25% and 0.031% for the branching fraction B(t → bH ± ) × B(H ± → τ ± ν τ ). Data and samples of simulated eventsThe ATLAS experiment [27] is a multipurpose detector with a forward-backward symmetric cylindrical geometry with respect to the LHC beam-axis.2 The innermost layers of ATLAS consist of tracking detectors in the pseudorapidity range |η| < 2.5, including the insertable B-layer [28, 29] installed for 2 The ATLAS experiment uses a right-handed coordinate system with its origin at the nominal interaction point (IP) in the centre of the detector and the z-axis along the beam pipe. The x-axis points from the IP to the centre of the LHC ring, and the y-axis points upward. Cylindrical coordinates (r, φ) are used in the transverse plane, φ being the azimuthal angle around the z-axis. The pseudorapidity is defined in terms of the polar angle θ as η = − ln[tan(θ/2)]. Transverse momenta are computed from the three-momenta ì p as p T = | ì p| sin θ. The distance in the η-φ space is commonly referred to as ∆R = (∆η) 2 + (∆φ) 2 . Analysis strategyThis paper describes a search for a charged Higgs boson decaying via H + → τν in topologies where it is produced either in top-quark decays or in association with a top-quark. Depending on whether the top-quark produced with the H + decays hadronically or semileptonically, two channels are targeted: τ had-vis +jets or τ had-vis +lepton, respectively. The corresponding signal regions are described below.6

Search for the Higgs boson produced in association with a vector boson and decaying into two spin-zeroparticles in the H → aa → 4b channel in p p collisions at √ s = 13 TeV with the ATLAS detectorThe ATLAS Collaboration A search for exotic decays of the Higgs boson into a pair of spin-zero particles, H → aa, where the a-boson decays into b-quarks promptly or with a mean proper lifetime cτ a up to 6 mm and has a mass in the range of 20-60 GeV, is presented. The search is performed in events where the Higgs boson is produced in association with a W or Z boson, giving rise to a signature of one or two charged leptons (electrons or muons) and multiple jets from b-quark decays. The analysis is based on the dataset of proton-proton collisions at √ s = 13 TeV recorded in 2015 and 2016 by the ATLAS detector at the CERN Large Hadron Collider, corresponding to an integrated luminosity of 36.1 fb −1 . No significant excess of events above the Standard Model background prediction is observed, and 95% confidence-level upper limits are derived for the production cross-sections for pp → W H, Z H and their combination, times the branching ratio of the decay chain H → aa → 4b. For a-bosons which decay promptly, the upper limit on the combination of cross-sections for W H and Z H times the branching ratio of H → aa → 4b ranges from 3.0 pb for m a = 20 GeV to 1.3 pb for m a = 60 GeV, assuming that the ratio of W H to Z H cross-sections follows the Standard Model prediction. For a-bosons with longer proper lifetimes, the most stringent limits are 1.8 pb and 0.68 pb, respectively, at cτ a ∼ 0.4 mm.The discovery of the Higgs boson by the ATLAS and CMS collaborations [1, 2] at the Large Hadron Collider (LHC) has been a major achievement for the Standard Model (SM). A comprehensive programme to explore the properties of this particle is underway, including measurements of the branching ratios to SM particles and searches for decays into "exotic" or non-SM particles. Exotic Higgs boson decays are a powerful probe for physics beyond the SM (BSM). The Higgs boson has a very narrow decay width, so even a small coupling to a non-SM particle could open up a sizeable decay mode. Measurements at the LHC are in agreement with SM predictions, constraining the non-SM branching ratio of the Higgs boson to less than approximately 30% at 95% confidence level (CL) using the 7 and 8 TeV datasets [3][4][5].Despite this experimental triumph, there is still ample room for exotic Higgs boson decays compatible with observations to date.The Higgs boson has been proposed as a possible "portal" for hidden-sector particles to interact with SM particles [6][7][8]. Exotic decays in particular are predicted by many BSM theories [9], including those with an extended Higgs sector such as the Next-to-Minimal Supersymmetric Standard Model (NMSSM) [10][11][12][13][14], models with a first-order electroweak phase transition [15,16], models with neutral naturalness [17][18][19] and models of dark matter [20][21][22][23][24].The decay of the Higgs boson into a pair of sp...