Rubin-LSST

Abstract:

A search for leptoquark pair production decaying into te-t¯e+ or tμ-t¯μ+ in final states with multiple leptons is presented. The search is based on a dataset of pp collisions at s=13TeV recorded with the ATLAS detector during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of 139 fb-1. Four signal regions, with the requirement of at least three light leptons (electron or muon) and at least two jets out of which at least one jet is identified as coming from a b-hadron, are considered based on the number of leptons of a given flavour. The main background processes are estimated using dedicated control regions in a simultaneous fit with the signal regions to data. No excess above the Standard Model background prediction is observed and 95% confidence level limits on the production cross section times branching ratio are derived as a function of the leptoquark mass. Under the assumption of exclusive decays into te- (tμ-), the corresponding lower limit on the scalar mixed-generation leptoquark mass mLQmixd is at 1.58 (1.59) TeV and on the vector leptoquark mass mU~1 at 1.67 (1.67) TeV in the minimal coupling scenario and at 1.95 (1.95) TeV in the Yang–Mills scenario.

Abstract:

<jats:title>Abstract</jats:title><jats:p>We present a cosmological analysis of the combination of the DES-Y3, KiDS-1000 and HSC-DR1 weak lensing samples under a joint harmonic-space pipeline making use of angular scales down to ℓ<jats:sub>max</jats:sub>=4500, corresponding to significantly smaller scales (δθ ~ 2.4') than those commonly used in cosmological weak lensing studies. We are able to do so by accurately modelling non-linearities and the impact of baryonic effects using<jats:monospace>Baccoemu</jats:monospace>. We find<jats:italic>S</jats:italic><jats:sub>8</jats:sub>≡<jats:italic>σ</jats:italic><jats:sub>8</jats:sub>√(Ω<jats:sub>m</jats:sub>/0.3) = 0.795<jats:sup>+0.015</jats:sup><jats:sub>-0.017</jats:sub>, in relatively good agreement with CMB constraints from<jats:italic>Planck</jats:italic>(less than ~1.8<jats:italic>σ</jats:italic>tension), although we obtain a low value of Ω<jats:sub>m</jats:sub>=0.212<jats:sup>+0.017</jats:sup><jats:sub>-0.032</jats:sub>, in tension with<jats:italic>Planck</jats:italic>at the ~3σ level. We show that this can be recast as an H<jats:sub>0</jats:sub>tension if one parametrises the amplitude of fluctuations and matter abundance in terms of variables without hidden dependence on H<jats:sub>0</jats:sub>. Furthermore, we find that this tension reduces significantly after including a prior on the distance-redshift relationship from BAO data, without worsening the fit. In terms of baryonic effects, we show that failing to model and marginalise over them on scales<jats:italic>ℓ</jats:italic>≲ 2000 does not significantly affect the posterior constraints for DES-Y3 and KiDS-1000, but has a mild effect on deeper samples, such as HSC-DR1. This is in agreement with our ability to only mildly constrain the parameters of the Baryon Correction Model with these data.</jats:p>

Abstract:

DUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals.

Abstract:

A search is presented for the pair production of higgsinos 𝜒˜ in gauge-mediated supersymmetry models, where the lightest neutralinos 𝜒˜ 0 1 decay into a light gravitino 𝐺˜ either via a Higgs ℎ or 𝑍 boson. The search is performed with the ATLAS detector at the Large Hadron Collider using 139 fb−1 of proton–proton collisions at a centre-of-mass energy of √ 𝑠 = 13 TeV. It targets final states in which a Higgs boson decays into a photon pair, while the other Higgs or 𝑍 boson decays into a 𝑏𝑏¯ pair, with missing transverse momentum associated with the two gravitinos. Search regions dependent on the amount of missing transverse momentum are defined by the requirements that the diphoton mass should be consistent with the mass of the Higgs boson, and the 𝑏𝑏¯ mass with the mass of the Higgs or 𝑍 boson. The main backgrounds are estimated with data-driven methods using the sidebands of the diphoton mass distribution. No excesses beyond Standard Model expectations are observed and higgsinos with masses up to 320 GeV are excluded, assuming a branching fraction of 100% for 𝜒˜ 0 1 → ℎ𝐺˜. This analysis excludes higgsinos with masses of 130 GeV for branching fractions to ℎ𝐺˜ as low as 36%, thus providing complementarity to previous ATLAS searches in final states with multiple leptons or multiple 𝑏-jets, targeting different decays of the electroweak bosons.