Performance of the LHCb Outer Tracker

Abstract

The LHCb Outer Tracker is a gaseous detector covering an area of 5 × 6 m 2 with 12 double layers of straw tubes. The detector with its services are described together with the commissioning and calibration procedures. Based on data of the first LHC running period from 2010 to 2012, the performance of the readout electronics and the single hit resolution and efficiency are presented.The efficiency to detect a hit in the central half of the straw is estimated to be 99.2%, and the position resolution is determined to be approximately 200 µm. The Outer Tracker received a dose in the hottest region corresponding to 0.12 C/cm, and no signs of gain deterioration or other ageing effects are observed.

Angular analysis of the B0 → K*0e+e− decay in the low-q2 region

“…The LHCb detector is a single-arm forward spectrometer covering the pseudorapidity range 2 < η < 5, designed for the study of particles containing b or c quarks. The detector includes a high-precision tracking system consisting of a silicon-strip vertex detector surrounding the pp interaction region [20], a large-area silicon-strip detector located upstream of a dipole magnet with a bending power of about 4 Tm, and three stations of silicon-strip detectors and straw drift tubes [21] placed downstream of the magnet. The tracking system provides a measurement of momentum, p, with a relative uncertainty that varies from 0.5% at low momentum to 1.0% at 200 GeV/c.…”

Study of Beauty Hadron Decays into Pairs of Charm Hadrons

“…[13][14][15][16][17][18]. Samples of simulated events are used to determine selection efficiencies, to model candidate distributions, and to investigate possible background contributions.…”

Measurement of the CP asymmetry in B− → D− sD0 and B− → D−D0 decays

“…The detector includes a high-precision tracking system consisting of a silicon-strip vertex detector surrounding the pp interaction region [20], a large-area silicon-strip detector located upstream of a dipole magnet with a bending power of about 4 Tm, and three stations of siliconstrip detectors and straw drift tubes [21] placed downstream of the magnet. The polarity of the dipole magnet is reversed periodically throughout data-taking, to cancel, to first order, asymmetries in the detection efficiency due to nonuniformities in the detector response.…”