Rubin-LSST

Abstract:

Results of a search for new particles decaying into eight or more jets and moderate missing transverse momentum are presented. The analysis uses 139 fb−1 of proton-proton collision data at 𝑠√ = 13 TeV collected by the ATLAS experiment at the Large Hadron Collider between 2015 and 2018. The selection rejects events containing isolated electrons or muons, and makes requirements according to the number of b-tagged jets and the scalar sum of masses of large-radius jets. The search extends previous analyses both in using a larger dataset and by employing improved jet and missing transverse momentum reconstruction methods which more cleanly separate signal from background processes. No evidence for physics beyond the Standard Model is found. The results are interpreted in the context of supersymmetry-inspired simplified models, significantly extending the limits on the gluino mass in those models. In particular, limits on the gluino mass are set at 2 TeV when the lightest neutralino is nearly massless in a model assuming a two-step cascade decay via the lightest chargino and second-lightest neutralino.

Abstract:

© 2020 Oxford University Press. All rights reserved. The paper 'Tomographic measurement of the intergalactic gas pressure through galaxy-tSZ cross-correlations' was published inMNRAS, 491, 5464-5480 (2020). After publication a typographical error in our analysis pipeline code was discovered, which slightly affected some of our results. In particular, our implementation of the generalised NFW profile (GNFW) described in Arnaud et al. (2010) lacked a factor of 1 - bH in the calculation of R500. We have corrected this error, re-run our analysis and present our updated results and comments (where applicable) in this manuscript. (i) Table 3 is updated with new best-fitting values. (ii) Likewise, Figs 8 and 9 are also updated with the new values of the best-fitting 1 - bHand<bPe>. (iii) Finally, our combined constraint on bH following this procedure (equation 48) is 1 - bH= 0.75 ± 0.03. While the main conclusions remain unchanged, it is worth pointing out that the best-fitting mass bias value 1 - bH= 0.75 ± 0.03 is now at a ~3-4s tension with the results measured by Planck Collaboration et al. (2016a) (1 - bH= 0.58 ± 0.04), combining tSZ cluster number counts and the TT CMB power spectrum. Consequently, our results can no longer be viewed as evidence of compatibility between the best-fit cosmology and the clustering properties of galaxies in the datasets used. Further, the best-fitting value of the mass bias is no longer at odds with the one derived from hydrodynamical simulations (Biffi et al. 2016), the estimate from CMB lensing mass calibration (Zubeldia & Challinor 2019), and other direct calibration efforts (e.g. Smith et al. 2016; Eckert et al. 2019), which seem to prefer smaller missing mass fractions (1 - bH~ 0.8). Lastly, our results are in agreement with Chiang et al. (2020), who explore the cosmic thermal history using SZ tomography.