Searches for BSM Resonances in ATLAS

Many new physics models predict the existence of new particles. This talk summarizes recent ATLAS searches for Beyond-the-Standard-Model heavy resonances which decay to pairs of bosons, heavy quarks, or leptons, using Run 2 data collected at the LHC. The experimental methods are explained, including the jet substructure techniques used in some searches to disentangle the hadronic decay products in highly boosted configurations

Search for heavy resonances decaying into a WW boson and a Higgs boson in final states with leptons and bb-jets in 139 fb−1139~fb^{-1} of pppp collisions at s=13 TeV\sqrt{s}=13~\mathrm{TeV} with the ATLAS detector

This poster presents a search for a new resonance $W^\prime$ decaying into a $W$ boson and a $125~\mathrm{GeV}$ Higgs boson $H$ in the $\ell\nu bb$ final states, where $\ell = e,~\mu,~\mathrm{or}~\tau$, using $pp$ collision data at 13 TeV corresponding to an integrated luminosity of 139 fb$^{-1}$ collected by the ATLAS detector at the LHC. The search considers the one-lepton channel, where an electron or muon is successfully reconstructed, as well as the zero-lepton channel relying on missing transverse momentum when the electron or muon from the $W$-boson decay is not reconstructed, or when $\ell$ is a hadronically decaying $\tau$-lepton. The search is conducted by examining the reconstructed invariant or transverse mass distributions of $W^\prime \to WH$ candidates in the mass range from $400~\mathrm{GeV}$ to $5~\mathrm{TeV}$. No significant excess is observed and $95\%$ confidence level upper limits between 0.7~pb and 0.4~fb are placed on the production cross-section times branching fraction of $W^\prime$ bosons in heavy-vector-triplet models

Improved track reconstruction for prompt and long-lived particles in ATLAS for the LHC Run 3

In preparation for LHC Run 3, ATLAS completed a major effort to improve the track reconstruction performance for prompt and long-lived particles. Resource consumption was halved while expanding the charged-particle reconstruction capacity. Large-radius track (LRT) reconstruction, targeting long-lived particles (LLP), was optimized to run in all events expanding the potential phase-space of LLP searches. The detector alignment precision was improved to avoid limiting factors for precision measurements of Standard Model processes. Mixture density networks and simulating radiation damage effects improved the position estimate of charged particles overlapping in the ATLAS pixel detector, bolstering downstream algorithms' performance. The ACTS package was integrated into the ATLAS software suite and is responsible for primary vertex reconstruction. The poster will highlight the above achievements and report on the readiness of the ATLAS detector for Run 3 collisions

Improvements to ATLAS Inner Detector Track reconstruction for LHC Run-3

This document summarises the main changes to the ATLAS experiment's Inner Detector Track reconstruction software chain in preparation of LHC Run 3 (2022-2024). The work was carried out to ensure that the expected high-activity collisions with on average 50 simultaneous proton-proton interactions per bunch crossing (pile-up) can be reconstructed promptly using the available computing resources. Performance figures in terms of CPU consumption for the key components of the reconstruction algorithm chain and their dependence on the pile-up are shown. For the design pile-up value of 60 the updated track reconstruction is a factor of 2 faster than the previous version.This document summarises the main changes to the ATLAS experiment’s Inner Detector Track reconstruction software chain in preparation of LHC Run 3 (2022-2024). The work was carried out to ensure that the expected high-activity collisions with on average 50 simultaneous proton-proton interactions per bunch crossing (pile-up) can be reconstructed promptly using the available computing resources. Performance figures in terms of CPU consumption for the key components of the reconstruction algorithm chain and their dependence on the pile-up are shown. For the design pile-up value of 60 the updated track reconstruction is a factor of 2 faster than the previous version

Improvements to ATLAS Inner Detector Track reconstruction for LHC Run-3

This talk summarises the main changes to the ATLAS experiment’s Inner Detector Track reconstruction software chain in preparation of LHC Run 3 (2022-2024). The work was carried out to ensure that the expected high-activity collisions with on average 50 simultaneous proton-proton interactions per bunch crossing (pile-up) can be reconstructed promptly using the available computing resources. Performance figures in terms of CPU consumption for the key components of the reconstruction algorithm chain and their dependence on the pile-up are shown. For the design pile-up value of 60 the updated track reconstruction is a factor of 2 faster than the previous version

Search for heavy resonances decaying into a Z or W boson and a Higgs boson in final states with leptons and b-jets

The poster presents the full run-2 results for the search for a heavy resonance decaying into a Z or W boson and a Standard Model Higgs boson (h), with the Z or W boson decaying into two leptons and the Higgs boson decaying into two b quarks. The search probed the reconstructed invariant or transverse mass distributions of the Zh and Wh candidates in the mass range from 220 GeV to 5 TeV. Upper limits at the 95% CL have been set on the gluon-gluon fusion production cross sections of a pseudoscalar Higgs boson (A) in the two-Higgs-doublet models and the Drell-Yan production cross sections of heavy vector bosons (Z' and W') in a heavy-vector-triplet model