G. D. Patel

Radiation damage in the LHCb vertex locator

LHCb is a dedicated experiment to study New Physics in the decays of beauty and charm hadrons at the Large Hadron Collider (LHC) at CERN. The beauty and charm hadrons are identified through their flight distance in the Vertex Locator (VELO), and hence the detector is critical for both the trigger and offline physics analyses. Due to their close proximity to the LHC beam the VELO sensors are exposed to higher ftuences than those of any other LHC subdetector. These proceedings present the primary results from radiation damage studies performed from the start of LHC data taking until late 2012. They include the first observation of type-inversion at the LHC, the highest statistics measurement of the silicon effective band gap after irradiation, and the observation of a radiation-induced charge loss effect due to the presence of a second metal layer.

RADIAL WIRE DRIFT CHAMBERS FOR THE H1 FORWARD TRACK DETECTOR AT HERA: DESIGN, CONSTRUCTION AND PERFORMANCE

Abstract The Forward Track Detector (FTD) in the H1 experiment at the HERA electron-proton collider includes three large radial wire drift chambers for accurate charged track reconstruction and particle identification. The chambers achieve the simultaneous requirements of good space point determination and good pulse height measurement. The latter is exploited for enhanced electron/hadron discrimination using X-ray emission from a transition radiator which precedes each chamber. The design, assembly and operating characteristics of the chambers are described.

Simultaneous track reconstruction and electron identification in the H1 radial drift chambers

Abstract Results of prototype tests of the radial-wire drift chambers of the H1 forward track detector are presented. Choice of a suitable gas mixture and careful design of the chambers to include the possibility of efficient X-ray detection have shown that tracks can be reconstructed with good accuracy (σ ≈ 110–150 μm) and that simultaneously electron identification can be achieved by pulse integral analysis of ionization energy deposition due to both dE/dx and transition radiation. For 90% electron acceptance the pion contamination is 8% at high momentum (≈ 60 GeV/c). At lower momenta, electron identification is further enhanced by the multiple sampling of pulse integrals in such chambers, resulting at 5 GeV/c in a pion contamination of ≈ 0.5%.

Inclusive production of vector and tensor mesons in antiproton-proton annihilation and non-annihilation interactions at 9.1 GeV/c

Cross sections have been determined for the inclusive production of vector (ϱ0, ω, K∗) and tensor (f, A2±) mesons in pp reactions at 9.1 GeV/c for both annihilation and non-annihilation processes. Distributions in the Feynman variable x and transverse momentum squared, pT2, have been examined for the ϱ0, ω and f mesons. The slopes for pT2 appear to be exponential and decrease with increasing particle mass for both annihilation and non-annihilation reactions, furthermore the slopes have consistently higher values for non-annihilation reactions. Comparisons with other data indicate that the ratio ϱ0/π− is independent of antiproton momentum in annihilation processes.

TRACK FINDING AND FITTING IN THE H1 FORWARD TRACK DETECTOR

Abstract The tracking environment in the H1 Forward Track Detector, where the hit multiplicity from proton fragments is high, is particularly hostile. The techniques and software which have been developed for pattern recognition and Kalman fitting of charged particle tracks in this region are described in detail.

Precision reconstruction of charged tracks with simultaneous electron identification in a gaseous detector using transition radiation

Abstract Results are presented from tests of a radial wire drift chamber, the design of which is optimised for both accurate spatial reconstruction of charged tracks and efficient detection of incident X-rays. With flash digitised readout, we demonstrate that analysis of pulse profile can yield good spatial accuracy (σ drift ∼150μm, σ chdiv ∼1% wire length) together with useful hadron/electron discrimination if(π/e∼8% at 60 GeV> c ) using a transition radiator immediately preceding the chamber. The exploitation of this technique at high energy proton-proton and electron-proton collider storage rings is briefly discussed.

The H1 Forward Track Detector at HERA II

In order to maintain efficient tracking in the forward region of H1 after the luminosity upgrade of the HERA machine, the H1 Forward Track Detector was also upgraded. While much of the original software and techniques used for the HERA I phase could be reused, the software for pattern recognition was completely rewritten. This, along with several other improvements in hit finding and high-level track reconstruction, are described in detail together with a summary of the performance of the detector.

INCLUSIVE RESONANCE PRODUCTION IN 7.3-GEV/C ANTI-P P INTERACTIONS

AbstractWe present results on inclusive baryon and meson resonance production in

Electron identification in the H1 radial wire drift chambers

\bar pp