Performance of the LHCb outer tracker

The LHCb Outer Tracker is a gaseous detector covering an area of 5 × 6 m2 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

Search for long-lived heavy charged particles using a ring imaging Cherenkov technique at LHCb

A search is performed for heavy long-lived charged particles using 3.0 fb$^{-1}$ of pp collisions collected at $\sqrt{s}$= 7 and 8 TeV with the LHCb detector. The search is mainly based on the response of the ring imaging Cherenkovdetectors to distinguish the heavy, slow-moving particles from muons. No evidence is found for the production of such long-lived states. The results are expressed as limits on the Drell-Yan production of pairs of long-lived particles, with both particles in the LHCb pseudorapidity acceptance, $1.8 < \eta < 4.9$. The mass-dependent cross-section upper limits are in the range 2-4 fb (at 95\% CL) for masses between 124 and 309 GeV/c$^2$

Search for long-lived particles decaying to jet pairs

A search is presented for long-lived particles with a mass between 25 and 50 GeV$/c^2$ and a lifetime between 1 and 200 ps in a sample of proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=7$ TeV, corresponding to an integrated luminosity of 0.62 fb$^{-1}$, collected by the LHCb detector. The particles are assumed to be pair-produced by the decay of a Standard Model-like Higgs boson. The experimental signature of the long-lived particle is a displaced vertex with two associated jets. No excess above the background is observed and limits are set on the production cross-section as a function of the long-lived particle mass and lifetime

The tracking system at LHCb in Run 2: hardware alignment systems, online calibration, radiation tolerance and 4D tracking with timing

The Outer Tracker detector of LHCb experiment is a gaseous straw tube tracker that measures the drift time with a resolution of $2.4~\mathrm{ns}$ and track with spacial resolution of $171~\mu \mathrm{m}$ . The maximum drift time extracted from data is $35~\mathrm{ns}$ . The dedicated optical alignment system RASNIK shows that the construction supporting the Outer Tracker detector is mechanically a rigid system. The assistance in particle identification for protons and pions is also presented

Spectral Detection of Lithium Uptake in Vegetation for Forensic Locating of Methamphetamine Lab Sites

Abstract Methamphetamine is a controlled substance having a great potential for abuse and addiction. Millions of Americans have tried this stimulant, so the need to stop its production is rapidly increasing. One approach that could assist in this regard is the use of spectral analysis of vegetation growing on land suspected of being a methamphetamine dump site. This could allow law enforcement to use multispectral data to examine the surrounding land under suspicion and obtain probable cause for a warrant for further forensic investigation of the site. As part of its production, lithium metal is introduced with anhydrousammonia to convert pseudoephedrine to methamphetamine. After this process, the remnant lithium is discarded nearby outdoors where weedy plants (such as Arabidopsis thaliana) can uptake the waste. The amount of lithium in Arabidopsis tissue can be ascertained through biochemical analysis and relatively high concentrations have the potential to affect reflected energy in particular spectral wavelengths. An experiment was conducted to determine if lithium uptake into the tissue of Arabidopsis could be discerned spectrally. T-test and linear regression evaluations found that the spectral responses of lithium treated plants were statistically different from those of controls in certain visible and near-infrared regions