Muons in the ATLAS detector are reconstructed by combining the information from the two tracking devices: the Inner Detector and the Muon Spectrometer (MS), located in the outermost part of the ...experiment. Until they reach the MS, muons traverse typically 100 radiation lengths (X0) of material, most part instrumented by the electromagnetic and hadronic calorimeters. The proper account for multiple scattering and energy loss effects is essential for the reconstruction and the use of the calorimeter measurement can improve the transverse momentum resolution, specially in case of high energy deposits. On the other hand, the calorimeter activity around a muon, or conversely its isolation, is one of the most powerful features to distinguish W and Z decays from semi-leptonic decays of heavy flavour mesons (containing b and c quarks). The principle of the software package that performs these tasks, called TrackInCaloTools is presented together with the expected performance in physics analyses.
Limited therapies are available for large (≥40 mm) unresectable hepatocellular carcinoma (HCC). Currently, the standard treatment with transarterial chemoembolisation (TACE) is unsatisfactory with ...high recurrence rate and limited effect on survival. Laser Ablation (LA) has emerged as a relatively new technique characterized by high efficacy and good safety. This study is aimed to evaluate the efficacy of LA in comparison to TACE in patients with large HCC.
Eighty-two patients with a single HCC nodule ≥40 mm (BCLC stage A or B) were enrolled in this case-control study. Forty-one patients were treated with LA and 41 patients were treated with TACE. Response to therapy was evaluated according to the mRECIST criteria. Survival was calculated with Kaplan-Meier from the time of cancer diagnosis to death with values censored at the date of the last follow-up.
Twenty-six (63.4%) and 8 (19.5%) patients had a complete response after LA and TACE, respectively (
< 0.001). Subsequently we stratified the HCCs in 3 categories according to the nodule size: 40-50 mm, 51-60 mm, and >60 mm. LA resulted superior to TACE especially in nodules ranging between 51 and 60 mm in diameter, with a complete response rate post-LA and post-TACE of 75% and 14.3%, respectively (
= 0.0133). The 36 months cumulative survival rate in patients treated with LA and TACE was 55.4% and 48.8%, respectively. The disease recurrence rates after LA and TACE were 19.5% and 75.0%, respectively.
LA is a more effective therapeutic option than TACE in patients with solitary large HCC.
Results are presented of a search for supersymmetric particles in events with large missing transverse momentum and at least one heavy flavour jet candidate in sqrt{s} = 7 TeV proton-proton ...collisions. In a data sample corresponding to an integrated luminosity of 35 pb-1 recorded by the ATLAS experiment at the Large Hadron Collider, no significant excess is observed with respect to the prediction for Standard Model processes. For R-parity conserving models in which sbottoms (stops) are the only squarks to appear in the gluino decay cascade, gluino masses below 590 GeV (520 GeV) are excluded at the 95% C.L. The results are also interpreted in an MSUGRA/CMSSM supersymmetry breaking scenario with tan(beta)=40 and in an SO(10) model framework.
A search for squarks and gluinos in final states containing jets, missing transverse momentum and no electrons or muons is presented. The data were recorded by the ATLAS experiment in sqrt(s) = 7 TeV ...proton-proton collisions at the Large Hadron Collider. No excess above the Standard Model background expectation was observed in 35 inverse picobarns of analysed data. Gluino masses below 500 GeV are excluded at the 95% confidence level in simplified models containing only squarks of the first two generations, a gluino octet and a massless neutralino. The exclusion increases to 870 GeV for equal mass squarks and gluinos. In MSUGRA/CMSSM models with tan(beta)= 3, A_0=0 and mu>0, squarks and gluinos of equal mass are excluded below 775 GeV. These are the most stringent limits to date.
This Letter reports a measurement of the muon charge asymmetry from W bosons produced in proton-proton collisions at a centre-of-mass energy of 7 TeV with the ATLAS experiment at the LHC. The ...asymmetry is measured in the W→μν decay mode as a function of the muon pseudorapidity using a data sample corresponding to a total integrated luminosity of 31 pb−1. The results are compared to predictions based on next-to-leading order calculations with various parton distribution functions. This measurement provides information on the u and d quark momentum fractions in the proton.
We present studies of W and Z bosons with associated high energy photons produced in pp collisions at sqrt(s)=7 TeV. The analysis uses 35 pb-1 of data collected by the ATLAS experiment in 2010. The ...event selection requires W and Z bosons decaying into high pT leptons (electrons or muons) and a photon with ET>15 GeV separated from the lepton(s) by a distance Delta_R(l,gamma)>0.7 in eta-phi space. A total of 95 (97) pp->e nu gamma + X (pp->mu nu gamma + X) and 25 (23) pp->e+ e- gamma + X (pp->mu+ mu- gamma + X) event candidates are selected. The kinematic distributions of the leptons and photons and the production cross sections are measured. The data are found to agree with Standard Model predictions that include next-to-leading-order O(alpha alpha_s) contributions.
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