Rubin-LSST

Abstract:

With a new probabilistic technique for sampling interstellar object (ISO) orbits with high efficiency, we assess the observability of ISOs under a realistic cadence for the upcoming Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST). Using the Ōtautahi–Oxford population model, we show that there will be complex on-sky structure in the pattern of direction and velocity revealed by the detected ISO population, with the expected enhanced northern flux complicating efforts to derive population parameters from the LSST’s predominately southern footprint. For reasonable luminosity functions with slopes of 2.5 ≤ qs ≤ 4.0, the most discoverable ISOs have Hr ≃ 14.6−20.7. The slope of the luminosity function of ISOs will be relatively quickly constrained by the characteristics of the LSST detected population, such as the distributions of perihelia, velocity at infinity, and discovery circumstances. Discoveries are evenly split around their perihelion passage and are biased to lower velocities. After their discovery by LSST, it will be rare for ISOs to be visible for less than a month; most will have mr ≤ 23 for months, and the window for spectroscopic characterization could be as long as 2 yr. While these probabilistic assessments are robust against model or spatial density refinements that change the absolute numbers of ISO discoveries, our simulations predict a yield of 6–51 asteroidal ISOs, which is similar to previous works and demonstrates the validity of our new methods.

Abstract:

Liquid argon time projection chambers (LArTPCs) rely on highly pure argon to ensure that ionization electrons produced by charged particles reach readout arrays. ProtoDUNE Single-Phase (ProtoDUNE-SP) was an approximately 700-ton liquid argon detector intended to prototype the Deep Underground Neutrino Experiment (DUNE) Far Detector Horizontal Drift module. It contains two drift volumes bisected by the cathode plane assembly, which is biased to create an almost uniform electric field in both volumes. The DUNE Far Detector modules must have robust cryogenic systems capable of filtering argon and supplying the TPC with clean liquid. This paper will explore comparisons of the argon purity measured by the purity monitors with those measured using muons in the TPC from October 2018 to November 2018. A new method is introduced to measure the liquid argon purity in the TPC using muons crossing both drift volumes of ProtoDUNE-SP. For extended periods on the timescale of weeks, the drift electron lifetime was measured to be above 30 ms using both systems. A particular focus will be placed on the measured purity of argon as a function of position in the detector.

Abstract:

Abstract The jet energy calibration and its uncertainties are derived from measurements of the calorimeter response to single particles in both data and Monte Carlo simulation using proton–proton collisions at $$\sqrt{s} = 13$$ s = 13 TeV collected with the ATLAS detector during Run 2 at the Large Hadron Collider. The jet calibration uncertainty for anti- $$k_T$$ k T jets with a jet radius parameter of R $$_\textrm{jet} = 0.4$$ jet = 0.4 and in the central jet rapidity region is about 2.5% for transverse momenta ( $$p_{\text {T}}$$ p T ) of 20 $$\text {GeV}$$ GeV , about $$0.5\%$$ 0.5 % for $$p_{\text {T}} =300$$ p T = 300 $$\text {GeV}$$ GeV and $$0.7\%$$ 0.7 % for $$p_{\text {T}} =4$$ p T = 4 $$\text {TeV}$$ TeV . Excellent agreement is found with earlier determinations obtained from $$p_\textrm{T}$$ p T -balance based in situ methods ( $$Z/\gamma $$ Z / γ +jets). The combination of these two independent methods results in the most precise jet energy measurement achieved so far with the ATLAS detector with a relative uncertainty of $$0.3\%$$ 0.3 % at $$p_\textrm{T}=300$$ p T = 300 GeV and $$0.6\%$$ 0.6 % at 4 TeV. The jet energy calibration is also derived with the single-particle calorimeter response measurements separately for quark- and gluon-induced jets and furthermore for jets with R $$_\textrm{jet}$$ jet varying from 0.2 to 1.0 retaining the correlations between these measurements. Differences between inclusive jets and jets from boosted top-quark decays, with and without grooming the soft jet constituents, are also studied.