The ATLAS detector has been designed for operation at CERN's Large Hadron Collider. ATLAS includes a complex system of liquid argon calorimeters. The electronics for amplifying, shaping, sampling, ...pipelining, and digitizing the calorimeter signals is implemented on the Front End Boards (FEBs). This paper describes the design, implementation and production of the FEBs and presents measurement results from testing performed at several stages during the production process.
We present various properties of the production of the X(3872) and ψ(2S) states based on 10.4 fb−1 collected by the D0 experiment in Tevatron pp collisions at √s = 1.96 TeV. For both states, we ...measure the nonprompt fraction fNP of the inclusive production rate due to decays of b-flavored hadrons. We find the fNP values systematically below those obtained at the LHC. The fNP fraction for ψ(2S) increases with transverse momentum, whereas for the X(3872) it is constant within large uncertainties, in agreement with the LHC results. The ratio of prompt to nonprompt ψ(2S) production, (1 − fNP)=fNP, decreases only slightly going from the Tevatron to the LHC, but for the X(3872), this ratio decreases by a factor of about 3. We test the soft-pion signature of the X(3872) modeled as a weakly bound charm-meson pair by studying the production of the X(3872) as a function of the kinetic energy of the X(3872) and the pion in the X(3872)π center-of-mass frame. For a subsample consistent with prompt production, the results are incompatible with a strong enhancement in the production of the X(3872) at the small kinetic energy of the X(3872) and the π in the X(3872)π center-of-mass frame expected for the X þ soft-pion production mechanism. For events consistent with being due to decays of b hadrons, there is no significant evidence for the soft-pion effect, but its presence at the level expected for the binding energy of 0.17 MeV and the momentum scale Λ ¼ M(π) is not ruled out.
Human papillomaviruses (HPVs) have been etiologically linked to a subset of head and neck squamous cell carcinomas (HNSCCs), generally arising in young patients without a history of tobacco smoking ...or alcohol use. These tumors typically lack mutations in TP53 and may show enhanced sensitivity to chemoradiation therapy with a correspondingly better overall prognosis. The determination of the HPV status in HNSCC therefore has therapeutic implications. We compared the Ventana ISH iView Blue Plus Detection Kit in situ hybridization (ISH) system and the Roche Linear Array HPV Genotyping Test for the detection of HPV in 98 formalin-fixed, paraffin-embedded HNSCC samples. A moderate concordance rate (70.4%) was observed between ISH and the Linear Array assays. ISH detected HPV in 39.8% of cases, whereas Linear Array detected HPV in 57.1% of cases. Sensitivity and specificity of ISH for detecting HPV in HNSCC specimens were determined to be 58.9% and 85.7%, respectively, using the Linear Array as the method of comparison (McNemar test, P=0.003). ISH offers the advantage of visual cell-type localization of viral infection but overall it is less sensitive than the polymerase chain reaction-based detection of HPV in HNSCC.
Molecular and epidemiologic evidence indicates that human papillomavirus (HPV) is involved in the etiology of oral and oropharyngeal squamous cell carcinomas (SCCs). HPV(+) tumors appear to be ...clinically distinct from HPV(-) tumors, conferring improved survival outcomes for patients. Determination of the HPV status of tumors may assist in patient risk-stratification and ultimately guide optimum treatment. The primary aim of this study was to examine the distribution of HPV in oral and oropharyngeal SCCs as assessed using seven different in vitro amplification assays. The secondary aim was to correlate the distribution of HPV in tumors with clinical and demographic patient data.
Sixty-eight invasive oral/oropharyngeal SCCs were tested for HPV using four laboratory-developed PCR assays for HPV16 or 18 and three commercial tests, INNO-LiPA® HPV Genotyping Extra (Innogenetics), Linear Array® HPV Genotyping Test (Roche Diagnostics), and Invader® HPV16/18 ASRs (Hologic Corp.).
Consensus results between tests revealed that 71.9% of tumors were HPV(+), primarily with HPV16 (63.2%). Other genotypes were uncommon and generally occurred coincidently with HPV16. HPV-positivity was significantly higher in oropharyngeal tumors (76.9%), particularly of the tonsils (91.7%), versus oral cavity tumors (20.0%). HPV(+) tumors occurred in younger patients (average 54.4 years versus 61.1 years) and were significantly associated with lower histological differentiation (poorly, 100.0%; moderately, 65.6%; well-differentiated, 42.9%).
A high rate of HPV-positivity, especially involving HPV16, occurred in oropharyngeal tumors, with a lower rate in oral cavity SCCs; however, solitary infections with HPV18, 33 or 45 in a minority of cases signified the potential oncogenicity of these additional genotypes and the likely need to screen for these less common genotypes in clinical specimens.
We present a measurement of the forward-backward asymmetry in the production of B(±) mesons, A(FB)(B(±)), using B(±)→J/ψK(±) decays in 10.4 fb(-1) of pp̄ collisions at sqrts=1.96 TeV collected by ...the D0 experiment during Run II of the Tevatron collider. A nonzero asymmetry would indicate a preference for a particular flavor, i.e., b quark or ̄b antiquark, to be produced in the direction of the proton beam. We extract A(FB)(B(±)) from a maximum likelihood fit to the difference between the numbers of forward- and backward-produced B(±) mesons. We measure an asymmetry consistent with zero: A(FB)(B(±))=-0.24±0.41 (stat)±0.19 (syst)%.
Substantial molecular evidence exists to implicate human papillomavirus (HPV) in the pathogenesis of a subset of oral and oropharyngeal squamous cell carcinomas. Several studies have shown that ...HPV-associated oral/oropharyngeal tumors differ etiologically, biologically, and clinically from those that lack the virus. HPV infection confers a significant survival benefit; therefore, HPV detection in tumors could be used to risk-stratify patients and drive optimum treatment strategies. We explored the clinical utility of 6 polymerase chain reaction (PCR)-based or signal amplification-based methods in the detection of HPV in 68 invasive oral/oropharyngeal SSCs and 10 reactive tonsil specimens. Agreement for HPV16 results among the 5 different assays capable of detecting this genotype was substantial (multirater κ=0.72). Only moderate agreement was noted for the 3 assays capable of detecting HPV18 (multirater κ=0.43). HPV results for each assay were evaluated relative to a "majority" HPV result derived from the results of all the detection methods. An HPV16 E6 PCR assay showed the highest concordance with adjudicated consensus HPV16 results (98.7%; κ=0.97), followed by the TaqMan (93.4%; κ=0.87), Linear Array (92.1%; κ=0.84), and E7 PCR (92.1%; κ=0.84) assays, all of which had agreements exceeding 90%, whereas the HPV16/18 Invader assay was lower (85.5%; κ=0.71). The presence of high-risk HPV in a minority of "normal" tonsillar tissues may confound assessment of the virus in oral/oropharyngeal squamous cell carcinoma biopsies using in vitro amplification methods.
The ATLAS detector has been designed for operation at the Large Hadron Collider at CERN. ATLAS includes electromagnetic and hadronic liquid argon calorimeters, with almost 200,000 channels of data ...that must be sampled at the LHC bunch crossing frequency of 40 MHz. The calorimeter electronics calibration and readout are performed by custom electronics developed specifically for these purposes. This paper describes the system performance of the ATLAS liquid argon calibration and readout electronics, including noise, energy and time resolution, and long term stability, with data taken mainly from full-system calibration runs performed after installation of the system in the ATLAS detector hall at CERN.
We present the first measurements of the ratios of cross sections σ(pp → Z+c jet)/σ(pp → Z+jet) and σ(pp → Z+c jet)/σ(pp → Z+b jet) for the associated production of a Z boson with at least one charm ...or bottom quark jet. Jets have transverse momentum pT(jet)>20 GeV and pseudorapidity |η(jet)|<2.5. These cross section ratios are measured differentially as a function of jet and Z boson transverse momenta, based on 9.7 fb(-1) of pp collisions collected with the D0 detector at the Fermilab Tevatron Collider at √s=1.96 TeV. The measurements show significant deviations from perturbative QCD calculations and predictions from various event generators.
We present measurements of the differential cross section dσ/dργτ for the inclusive production of a photon in association with a b -quark jet for photons with rapidities |yγ| < 1.0 and 30 < ργτ < 300 ...GeV , as well as for photons with 1.5 <|yγ| < 2.5 and 30 < ργτ < 200 GeV, where ργτ is the photon transverse momentum. The b -quark jets are required to have pT > 15 GeV and rapidity |yjet| < 1.5. The results are based on data corresponding to an integrated luminosity of 8.7 fb-1, recorded with the D0 detector at the Fermilab Tevatron $p\bar{p}$ Collider at $\sqrt{s}$ =1.96 TeV. The measured cross sections are compared with next-to-leading order perturbative QCD calculations using different sets of parton distribution functions as well as to predictions based on the kT-factorization QCD approach, and those from the SHERPA and PYTHIA Monte Carlo event generators.
We present a measurement of the effective weak mixing angle parameter sin^{2}θ_{eff}^{ℓ} in ppover ¯→Z/γ^{*}→μ^{+}μ^{-} events at a center-of-mass energy of 1.96 TeV, collected by the D0 detector at ...the Fermilab Tevatron Collider and corresponding to 8.6 fb^{-1} of integrated luminosity. The measured value of sin^{2}θ_{eff}^{ℓ}μμ=0.23016±0.00064 is further combined with the result from the D0 measurement in ppover ¯→Z/γ^{*}→e^{+}e^{-} events, resulting in sin^{2}θ_{eff}^{ℓ}comb=0.23095±0.00040. This combined result is the most precise measurement from a single experiment at a hadron collider and is the most precise determination using the coupling of the Z/γ^{*} to light quarks.
PDF
