b-tagging with DC1 data

Abstract

This note describes the analysis of the b-tagging performances of the ATLAS Inner Detector expected in WH and ttH / tt events. The simulation, reconstruction and analysis were done in the framework of the ATLAS Data Challenge. The effects of the changes in the inner detector (increase of the b-layer radius, more realistic material estimate, staging of the intermediate pixel layer, disk and TRT C-wheels, increase of the pixel pitch size in the b-layer from 300 um to 400 um) were studied. The introduction of pile-up, detector inefficiencies and full vertex reconstruction brings the simulation results closer to the reality. New b-tagging methods show considerable improvements in the performances