A measurement of material in the ATLAS tracker using secondary hadronic interactions in 7 TeV pp collisions

H. WAHLBERG Y ATLAS COLLABORATION

JOURNAL OF INSTRUMENTATION

IOP PUBLISHING LTD

Lugar: Londres; Año: 2017

1748-0221

Knowledge of the material in the ATLAS inner tracking detector is crucial in understand-ing the reconstruction of charged-particle tracks, the performance of algorithms that identifyjets containing b-hadrons and is also essential to reduce background in searches for exoticparticles that can decay within the inner detector volume. Interactions of primary hadronsproduced in pp collisions with the material in the inner detector are used to map the loca-tion and amount of this material. The hadronic interactions of primary particles may result insecondary vertices, which in this analysis are reconstructed by an inclusive vertex-finding algorithm. Data were collected using minimum-bias triggersby the ATLAS detector operating at the LHC during 2010 at centre-of-mass energy s = 7 TeV, and correspond to an integ-rated luminosity of 19 nb −1 . Kinematic properties of these secondary vertices are used tostudy the validity of the modelling of hadronic interactions in simulation. Secondary-vertexyields are compared between data and simulation over a volume of about 0.7 m 3 around theinteraction point, and agreement is found within overall uncertainties.