ATLAS Upgrade Program Sarah Demers, US ATLAS Fellow with BNL Yale University 2013 US LHC Users Organization Annual Meeting

What ATLAS vulnerabilities appear with increased luminosity and time?

detector detector in pile-up What ATLAS vulnerabilities appear with increased luminosity and time? detector detector in pile-up

PHYSICS

PHYSICS The Standard Model Open access to new ideas and searches Continue to test SM Continue to use SM physics to measure efficiencies Open access to new ideas and searches Increase flexibility of trigger system

Current Work Includes: Insertable B-Layer Topological Trigger Combining muon and calorimeter objects – can make requirements on angular distributions masses to select signal or reject BG

Fast TracKer (FTK) Electronics for global tracking on every L1 Trigger to provide early access to tracking information at Level 2. Main motivation: b- and t-tagging

FTK Efficiencies for muons and pions with respect to truth (simulation) and offline reconstruction ATLAS-TDR-021-2013

2018 – 2022 300 fb-1 60 - 80 pile-up events Phase-I

Phase-I Level1 Calorimeter Trigger/Readout Muon New Small Wheel

Level 1 Calorimeter Trigger: Increased Granularity

Level 1 Calorimeter Trigger: Increased Granularity Current L1 Trigger Tower

Level 1 Calorimeter Trigger: Increased Granularity Current L1 Trigger Tower Full Detector Granularity

Level 1 Calorimeter Trigger: Increased Granularity Current L1 Trigger Tower Phase-II Supercell Full Detector Granularity

Muon New Small Wheel (NSW) A set of precision tracking and trigger detectors that can work at high rates with excellent time and spatial resolution. ATLAS-TDR-020-2013

Muon New Small Wheel Low purity (currenty) in the end-cap region

Segment finding for a 2 TeV Z’ decaying Muon New Small Wheel Segment finding for a 2 TeV Z’ decaying to a pair of muons

Phase-II 2024 – 203x 3000 fb-1 140 – 200 pile-up events Level 1 Track Trigger

The ATLAS Tracking Chambers

an example upgrade layout

channel occupancy with 200 pile-up interactions

Constraints Include Access

From ATLAS Phase-II Letter of Intent

Motivation for the Track Trigger

Performance assumptions based on full simulation for an upgraded ATLAS detector at a High-Luminosity LHC The ATLAS Collaboration ATLAS-PUB-2013-009

25 GeV for electrons and muons 60 GeV for photons and taus Performance assumptions based on full simulation for an upgraded ATLAS detector at a High-Luminosity LHC The ATLAS Collaboration ATLAS-PUB-2013-009 offline cuts of 25 GeV for electrons and muons 60 GeV for photons and taus 180 GeV for Missing ET

Performance assumptions based on full simulation for an upgraded ATLAS detector at a High-Luminosity LHC The ATLAS Collaboration ATLAS-PUB-2013-009

https://twiki.cern.ch/twiki/bin/view/AtlasPublic/UpgradePhysicsStudies

Sensitivity of ATLAS at HL-LHC to flavour changing neutral currents in top quark decays t → cH, with H → gg ATLAS-PHYS-PUB-2013-012

Prospects for benchmark SSUY search at high luminosity with the ATLAS Detector ATL-PUB-2013-001 The 95 % CL exclusion limits (dashed) and 5-sigma discovery reach (solid) for 300 inverse fb (red) and 3000 fb-1 (black) in the stop, neutralino-1 mass plane assuming a stop to top and neutralino-1 decay with a branching ratio of 100 %.

Propoer Decay Time Resolution

Conclusions Physics Goals drive the ATLAS upgrade Plan Increased Performance and Flexibility of our detector and trigger will allow us to use SM physics to understand our detector in new machine environments continue to Probe the Higgs Boson search for other physics beyond the SM respond to what we uncover at high energy!