The ATLAS tau trigger

Author

Tsuno, S.

Author_Institution

KEK, on behalf of ATLAS collaboration

fYear

2009

fDate

Oct. 24 2009-Nov. 1 2009

Firstpage

223

Lastpage

224

Abstract

The ATLAS tau trigger consists of three trigger levels: the first one (L1) is hardware based and uses FPGAs, while the second (L2) and third levels (EF -Event Filter-) are software based and use commodity computers. In this contribution, we discuss both the physics characteristics of tau leptons and the technical solutions to quick data access and fast algorithms. We show that L1 selects narrow jets in the calorimeter with an overall rejection against QCD jets of 300, whilst L2 and EF (referred together as High Level Trigger -HLT-) use all the detectors with full granularity and apply a typical rejection of 15 within the stringent timing requirements of the LHC. In the HLT there are two complementary approaches: specialized, fast algorithms are used at L2, while more refined and sophisticated algorithms, imported from the offline, are utilized in the EF.

Keywords

high energy physics instrumentation computing; nuclear electronics; particle calorimetry; position sensitive particle detectors; trigger circuits; ATLAS tau trigger; FPGA; LHC; QCD jets; calorimeter; event filter; fast algorithms; high level trigger; tau leptons; Collaborative software; Detectors; Electrons; Field programmable gate arrays; Hardware; Large Hadron Collider; Mesons; Physics; Software algorithms; Software performance;

fLanguage

English

Publisher

ieee

Conference_Titel

Nuclear Science Symposium Conference Record (NSS/MIC), 2009 IEEE

Conference_Location

Orlando, FL

ISSN

1095-7863

Print_ISBN

978-1-4244-3961-4

Electronic_ISBN

1095-7863

Type

conf

DOI

10.1109/NSSMIC.2009.5401789

Filename

5401789