3 research outputs found

    Search for R-parity-violating supersymmetry in a final state containing leptons and many jets with the ATLAS experiment using s√=13 TeV proton–proton collision data

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    A search for R-parity-violating supersymmetry in final states characterized by high jet multiplicity, at least one isolated light lepton and either zero or at least three b-tagged jets is presented. The search uses 139fb−1 of s√=13 TeV proton–proton collision data collected by the ATLAS experiment during Run 2 of the Large Hadron Collider. The results are interpreted in the context of R-parity-violating supersymmetry models that feature gluino production, top-squark production, or electroweakino production. The dominant sources of background are estimated using a data-driven model, based on observables at medium jet multiplicity, to predict the b-tagged jet multiplicity distribution at the higher jet multiplicities used in the search. Machine-learning techniques are used to reach sensitivity to electroweakino production, extending the data-driven background estimation to the shape of the machine-learning discriminant. No significant excess over the Standard Model expectation is observed and exclusion limits at the 95% confidence level are extracted, reaching as high as 2.4 TeV in gluino mass, 1.35 TeV in top-squark mass, and 320 (365) GeV in higgsino (wino) mass

    A comprehensive rock-magnetic, paleomagnetic, paleointensity and geochronologic study along the western Trans-Mexican volcanic belt: Geodynamic and geomagnetic implications

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    We present results from a comprehensive paleo-magnetic, rock magnetic, geochronologic, and paleointensity study on the Miocene volcanic rocks from the western Trans Mexican Volcanic Belt. A total of 58 sites composed of 7 to 21 consecutive volcanic cooling units from four separated stratigraphic sections have been collected. Our new radiometric dating results suggest that lava flows of the Jesus Maria sequence were erupted within a short time interval from 11.1±0.8 to 10±0.8 Ma during the C5n.2n normal polarity chron. The nearby Atotonilco section displays similar lithologic characteristics to the Jesus Maria sequence, with the top 3 lava flows probably belong to C5n.lr. Our geochronologic results from the Funicular section indicate that these lavas were formed in a longer time interval from 5.2±0.7 to 2.8±0.5 Ma. Based on rock-magnetic and microscopy observations the magnetic mineralogy of all samples is determined to be primary and unaltered Ti-poor titanomagnetites, resulting from oxy-exsolution of original titanomagnetite during the initial low cooling. Stable components of magnetization are determined after detailed thermal and alternating-field demagnetization. Our new results combined with existing regional paleomagnetic data indicate that the sampled areas have not undergone significant N-S displacement and block rotations since at least last 11 Ma. Accepted paleointensity determinations are of good technical quality with positive standard partial thermoremanent magnetization (pTRM) checks. Obtained paleoin¬tensity data range from 17.5 to 34.3 mT, suggesting the existence of both relatively high geomagnetic ield strength and low luctuations in late Miocene. Our results suggest that the studied rocks preserve a magnetic memory of the late Miocene geomagnetic ield and provide constraints for paleogeographic reconstructions. The new paleomagnetic data should help reine models for the tectonic evolution of the TMVB

    A comprehensive rock-magnetic, paleomagnetic, paleointensity and geochronologic study along the western Trans-Mexican volcanic belt: Geodynamic and geomagnetic implications

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    We present results from a comprehensive paleo-magnetic, rock magnetic, geochronologic, and paleointensity study on the Miocene volcanic rocks from the western Trans Mexican Volcanic Belt. A total of 58 sites composed of 7 to 21 consecutive volcanic cooling units from four separated stratigraphic sections have been collected. Our new radiometric dating results suggest that lava flows of the Jesus Maria sequence were erupted within a short time interval from 11.1 0.8 to 10 0.8 Ma during the C5n.2n normal polarity chron. The nearby Atotonilco section displays similar lithologic characteristics to the Jesus Maria sequence, with the top 3 lava flows probably belong to C5n.lr. Our geochronologic results from the Funicular section indicate that these lavas were formed in a longer time interval from 5.2 0.7 to 2.8 0.5 Ma. Based on rock-magnetic and microscopy observations the magnetic mineralogy of all samples is determined to be primary and unaltered Ti-poor titanomagnetites, resulting from oxy-exsolution of original titanomagnetite during the initial low cooling. Stable components of magnetization are determined after detailed thermal and alternating-field demagnetization. Our new results combined with existing regional paleomagnetic data indicate that the sampled areas have not undergone significant N-S displacement and block rotations since at least last 11 Ma. Accepted paleointensity determinations are of good technical quality with positive standard partial thermoremanent magnetization (pTRM) checks. Obtained paleointensity data range from 17.5 to 34.3 mT, suggesting the existence of both relatively high geomagnetic ield strength and low luctuations in late Miocene. Our results suggest that the studied rocks preserve a magnetic memory of the late Miocene geomagnetic ield and provide constraints for paleogeographic reconstructions. The new paleomagnetic data should help reine models for the tectonic evolution of the TMVB
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