Search for resonant production of tt¯ pairs in 4.8 fb-1 of integrated luminosity of pp¯ collisions at s=1.96 TeV
Physical Review D American Physical Society (APS) 84:7 (2011) 072004
The radiation hardness and temperature stability of Planar Light-wave Circuit splitters for the High Luminosity LHC
Journal of Instrumentation 6:10 (2011)
Abstract:
High Luminosity LHC (HL-LHC) Inner Tracker designs may include the sharing of Timing, Trigger and Control (TTC) signals between several tracker modules. This is possible because the highest frequency signals are common to all modules. Such designs are an attractive option because they reduce the number of optical links required and hence the cost. These designs will require optical signal splitters that are radiation hard up to high doses and capable of operating in cold temperatures. Optical splitters are available as either fused-fibre splitters or Planar Lightwave Circuit (PLC) splitters. PLC splitters are preferable because they are smaller than fusedfibre splitters. A selection of PLC splitters from different manufacturers and of two different technologies (silica and glass based) have been tested for radiation hardness up to a dose of 500 kGy(Si) and for temperature stability. All the tested splitters displayed small increases in insertion losses (< 0.1 dB) in reducing the operating temperature from 25°C to ?25°C. The silica based splitters from all manufacturers did not exhibit significant radiation induced insertion losses, despite the high dose they were exposed to. The glass based sample, however, had a per channel radiation induced insertion loss of up to 1.16 dB. Whilst the silica based splitters can be considered as qualified for HL-LHC use with regards to radiation hardness, the glass technology would require further testing at a lower, more realistic, dose to also be considered as a potential component for HL-LHC upgrade designs. © 2011 IOP Publishing Ltd and SISSA.Speedy Higgs boson discovery in decays to tau lepton pairs: h → ττ
Journal of High Energy Physics Springer Nature 2011:10 (2011) 80
Measurement of branching ratio and Bs0 lifetime in the decay Bs0→J/ψf0 (980) at CDF
Physical Review D - Particles, Fields, Gravitation and Cosmology 84:5 (2011)
Abstract:
We present a study of Bs0 decays to the CP-odd final state J/ψf 0(980) with J/ψ→μ+μ- and f 0(980)→π+π-. Using pp̄ collision data with an integrated luminosity of 3.8fb-1 collected by the CDF II detector at the Tevatron we measure a Bs0 lifetime of τ(Bs0→J/ψf0(980))=1.70-0.11+0.12(stat)±0.03(syst) ps. This is the first measurement of the Bs0 lifetime in a decay to a CP eigenstate and corresponds in the standard model to the lifetime of the heavy Bs0 eigenstate. We also measure the product of branching fractions of Bs0→J/ψf0(980) and f0(980)→π +π- relative to the product of branching fractions of Bs0→J/ψ and →K+K- to be Rf0 /=0.257±0.020(stat)±0.014(syst), which is the most precise determination of this quantity to date. © 2011 American Physical Society.Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
ArXiv 1109.6833 (2011)