ATLAS Trigger Configuration and Menus and some gauge

ATLAS Trigger Configuration and Menus (and some gauge couplings) Paul Bell Summary of 2009 1. Introduction to the ATLAS Trigger Menus and Configuration System 2. Work done/status report 3. Quartic gauge couplings

The ATLAS Trigger The ATLAS trigger reduces the 40 MHz bunch crossing rate to 200 Hz event output rate Decision times Implementation < 2. 2 s Hardware (FPGA) < 100 KHz ~ 40 ms ~1000 gen. purpose processors running optimised algorithms on ROIs ~2 KHz HLT ~ few sec ~1000 general purpose processors running “wrapped” offline algorithms ~200 Hz

Trigger Menus The processes recorded in the available 200 Hz are defined by the trigger menu The trigger menu must reflect the wide variety of processes of interest: ● Standard Model: jet production, electroweak processes, B-physics, top quarks, Higgs… + beyond the SM: SUSY, extra dimensions… → it therefore contains many basic physics objects reconstructed by the trigger: muons, electrons, jets, taus… Items in the L 1 menu EM threshold multiplicity EM item e. g. x 1 e. g. 1 EM 10 e. g. em 10 L 1 Menu is a collection of up to 256 items Signatures in the HLT menu EMROI L 2 tracking track? e. g. SCT tracking algorithm conditions EF tracking e OK? Signature e. g. “e 20” HLT Menu comprises many signatures: the final objects triggered on

Trigger Configuration System All 3 levels of the ATLAS trigger are configured from a central database, the Trigger. DB • Use of the DB gives you: The Trigger. DB in the Trigger Configuration system - Guaranteed configuration via unique “key” = primary key of the top level table - Easy reproducibility - Configuration history Configuration uploading Trigger. Tool GUI Offline access Online operation - Easy access to information offline DB contains: Trigger. DB Conf 2 COOL Trigger. Panel Run Control ● L 1 and HLT menus + complete configuration of L 1 hardware and HLT software needed to realise these menus, i. e. : config. = menu + setup COOL Conditions Database Interface layers L 1 hardware configuration HLT software configuration

Current Activities and Status • The contents of the menus are managed by the trigger menu group • A menu is deployed online thanks to the trigger configuration system • The 5 “menu experts” implement requests for certain triggers from the physics groups and create complete menus (Cosmics 2009, Initial. Beam, Lumi 1 E 31, etc) (I spent a lot of time standardising the Python framework in which we do this) • The final step in preparing a menu is to “upload” it to the trigger database • The menu experts then follow and understand the performance of the menu online and take decisions to control the trigger rates (lots of time at Point 1) • Status for first beams: - Given luminosity and filled bunches, trigger not needed for online rejection of events (though this was demonstrated) - Role of Higher Level Trigger was to send events from L 1 to the appropriate stream, according to their L 1 trigger type, L 1 Calo, Muons, etc - Highest “physics” rate seen from Min Bias Trigger Scintillators (MBTS) around 100 Hz - Remaining bandwidth filled with zero bias events from Beam Pickup detectors - More complex menus exercised by rerunning the HLT offline • For 2010, menus for higher luminosity are prepared, and we will see an evolution towards ever higher online rejection as bandwidth is used up

Current Activities and Status • Continued co-convening the ATLAS Trigger Configuration group (~10 people) - responsible for development, maintenance and support of the configuration system • “Online” developments during 2009 have included: - ability to update L 1, HLT and express stream prescales during a run - continued improvements to graphical user interfaces (much feedback) • “Offline”, I “took a leading role” in extending the system for use in MC production: - Established a dedicated “MC Trigger. DB” for MC specific configurations - Extended the interface software to allow configuration of offline jobs from the DB (for example the Level 1 simulation) - Integrated with the wider ATLAS core software to allow the choice of DB configuration to be specified in the ATLAS production scripts - Set up the mechanism to make the data available on the grid (T 2 production sites) - Established a validation procedure Þ DB-based configuration now used since MC 09 production Þ Trigger Configuration group now responsible for updating the MC DB as required • Last months mainly been dealing with bugs/feature requests e. g. from the menu group • Much development still remains: e. g. how to retrospectively simulate trigger for some period of data? One proposal is to simulate exactly the trigger conditions – we have the data in the DB after all, though need a whole new layer of software and tools. TBC…

Quartic gauge couplings A study of WWgg anomalous quartic gauge couplings in Wgg events at the LHC - Using custom W 2 PHO MC generator, now being used in 4 th year project