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CERN-LHC. Many extensions of the Standard Model posit the existence of heavy particles with long lifetimes. This article presents the results of a search for events containing at least one long-lived particle that decays at a significant distance from its production point into two leptons or into five or more charged particles. This analysis uses a data sample of proton-proton collisions at $\sqrt{s}$ = 8 TeV corresponding to an integrated luminosity of 20.3 fb$^{-1}$ collected in 2012 by the ATLAS detector operating at the Large Hadron Collider. No events are observed in any of the signal regions, and limits are set on model parameters within supersymmetric scenarios involving R-parity violation, split supersymmetry, and gauge mediation. In some of the search channels, the trigger and search strategy are based only on the decay products of individual long-lived particles, irrespective of the rest of the event. In these cases, the provided limits can easily be reinterpreted in different scenarios. Upper limits (95% CL) from the DV+$E_T^{miss}$ channel on the production cross-section and the corresponding event-level efficiencies (from Auxiliary Figure 9a) for two GGM SUSY models as a function of the $\tilde{\chi}_1^0$ proper decay distance $c\tau$. The models consider gluino pair production, with $\tilde{g}\to qq[\tilde{\chi}_1^0\to Z\tilde{G}]$ decays, $m(\tilde{g})$ = 1100 GeV and a $\tilde{\chi}_1^0$ mass in GeV as indicated. For comparison, the production cross-section for $m(\tilde{g})$ = 1100 GeV is $7.6\pm2.8$ fb.

Upper limits at 90% CL for the elements of the extended neutrino mixing matrix |Ue4|^2 and |Umu4|^2 depending on the assumed heavy neutral lepton mass. Upper limits on |U_mu4|^2 vs assumed neutrino mass [MeV].

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures. Related Article: Yong-gang Shi, Jun-wei Wang, Haijun Li, Guo-fei Hu, Xue Li, Soren K. Mellerup, Nan Wang, Tai Peng, Suning Wang|2018|Chemical Science|9|1902|doi:10.1039/C7SC03617E

Related Article: Neha Choudhary, Marı́a de Guadalupe Jaraquemada-Peláez, Kristof Zarschler, Xiaozhu Wang, Valery Radchenko, Manja Kubeil, Holger Stephan, Chris Orvig|2020|Inorg.Chem.|59|5728|doi:10.1021/acs.inorgchem.0c00509

Data from Fig 56-60c. The unfolded all-particle $R_g$ distribution for the more central of the two anti-kt R=0.8 jets with $p_T$ > 300 GeV, after the soft drop algorithm is applied for $\beta$ = 2, in data. All uncertainties described in the text are shown on the data. The distributions are normalized to the integrated cross section, $\sigma$. Each set of 6 bins corresponds to one $p_T$ bin in {300, 400, 600, 800, 1000, infinity } and 6 bins in $r_g$ (0.06310, 0.10000, 0.15849, 0.25119, 0.39811, 0.63096, 0.80000). Unfolded soft drop jet mass distributions for dijet events.

CERN-LHC. A search for the supersymmetric partners of quarks and gluons (squarks and gluinos) in final states containing hadronic jets and missing transverse momentum, but no electrons or muons, is presented. The data used in this search were recorded in 2015 and 2016 by the ATLAS experiment in $\sqrt{s}=13\mathrm{\ Te\kern -0.1em V}$ proton--proton collisions at the Large Hadron Collider, corresponding to an integrated luminosity of 36.1 fb$^{-1}$. The results are interpreted in the context of various models where squarks and gluinos are pair-produced and the neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 2.03$\mathrm{\ Te\kern -0.1em V}$ for a simplified model incorporating only a gluino and the lightest neutralino, assuming the lightest neutralino is massless. For a simplified model involving the strong production of mass-degenerate first- and second-generation squarks, squark masses below 1.55$\mathrm{\ Te\kern -0.1em V}$ are excluded if the lightest neutralino is massless. These limits substantially extend the region of supersymmetric parameter space previously excluded by searches with the ATLAS detector. Signal region efficiency for simplified model with squark pair production and direct decays to a quark and neutralino in SR RJR-C2.

Additional file 1. Appendix

CERN-LHC, ATLAS. A search for a right-handed gauge boson WR, decaying into a boosted right-handed heavy neutrino NR, in the framework of Left-Right Symmetric Models is presented. It is based on data from proton-proton collisions with a centre-of-mass energy of 13 TeV collected by the ATLAS detector at the Large Hadron Collider during the years 2015, 2016 and 2017, corresponding to an integrated luminosity of 80 fb−1. The search is performed separately for electrons and muons in the final state. A distinguishing feature of the search is the use of large-radius jets containing electrons. Selections based on the signal topology result in smaller background compared with to expected signal. No significant deviation from the Standard Model prediction is observed and lower limits are set in the WR and NR mass plane. Mass values of the WR smaller than 3.8-5 TeV are excluded for NR in the mass range 0.1-1.8 TeV. Expected 95% CL exclusion contours in the $(m_{N_R}, m_{W_R})$ plane in the electron channel.

Related Article: Scott Forbes, Fang Yuan, Kosuke Kosuda, Taras Kolodiazhnyi, Yurij Mozharivskyj|2016|J.Solid State Chem.|242|148|doi:10.1016/j.jssc.2016.04.015

Simulation of a black-hole binary system evolved by the SpEC code.