34 research outputs found
The kaon identification system in the NA62 experiment at CERN SPS
No full textThe main goal of the NA62 experiment at the CERN SPS accelerator is to measure the branching fraction of the ultra-rare decay K(+)→π(+)νbar nu with 10% accuracy. Key aspects of the detector configuration are described, with emphasis on tagging and timestamping the minority kaons in the high intensity, unseparated, charged-particle beam using KTAG, an upgraded version of a CEDAR differential Cherenkov detector. Data are presented showing that KTAG was successfully commissioned at CERN in November 2012
Measurement of the W+- boson cross section in the electron decay channel at [square root] s=7 TeV with the ATLAS detector
No full textAt the LHC, the process pp -+ W± X followed by the leptonic decays W- -+ e-v and W+ -+ e+lI is investigated to test the Standard Model in a completely new kinematic range. This thesis describes W± cross-section measurements using pp collisions recorded by the ATLAS detector in 2010. The charge dependence is measured both integrated and differentially in lepton pseudorapidity 'f); and analysis of the systematic uncertainties is presented. The results are compared with a recent publication by ATLAS which uses different reconstruction and background estimations. The cross-sections are also compared with theoretical predictions based on recent P DF sets determined recently by the CTEQ, MSTW, ABKM, HERAPDF and JR groups. The values of the W± cross-sections and their respective uncertainties, for 35.1 pb-1 at 7 TeV centre of mass energy, determined by this analysis, are: δfid/w+ x BR(W -+ e+ve) = 2.907 ± 0.015(stat.) ± 0.113(syst.) ± 0.099(lumi.) [nb] δfid/w+ x BR(W -+ e+ve) = 1.913 ± 0.012(stat.) ± 0.077(syst.) ± 0.065(lumi.) [nb]EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Measurement of the W+- boson cross section in the electron decay channel at [square root] s=7 TeV with the ATLAS detector
No full textAn observational retrospective matched cohort study of healthcare resource utilisation and costs in UK patients with moderate to severe osteoarthritis pain
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Development of the kaon tagging system for the NA62 experiment at CERN
No full textThe NA62 experiment at CERN aims to make a precision measurement of the ultra-rare decay , and relies on a differential Cherenkov detector (KTAG) to identify charged kaons at an average rate of 50 MHz in a 750 MHz unseparated hadron beam. The experimental sensitivity of NA62 to K-decay branching ratios (BR) of requires a time resolution for the KTAG of better than 100 ps, an efficiency better than 95% and a contamination of the kaon sample that is smaller than . A prototype version of the detector was tested in 2012, during the first NA62 technical run, in which the required resolution of 100 ps was achieved and the necessary functionality of the light collection system and electronics was demonstrated.The NA62 experiment at CERN aims to make a precision measurement of the ultra-rare decay , and relies on a differential Cherenkov detector (KTAG) to identify charged kaons at an average rate of 50 MHz in a 750 MHz unseparated hadron beam. The experimental sensitivity of NA62 to K-decay branching ratios (BR) of requires a time resolution for the KTAG of better than 100 ps, an efficiency better than 95% and a contamination of the kaon sample that is smaller than . A prototype version of the detector was tested in 2012, during the first NA62 technical run, in which the required resolution of 100 ps was achieved and the necessary functionality of the light collection system and electronics was demonstrated.The NA62 experiment at CERN aims to make a precision measurement of the ultra-rare decay K+→π+νν¯ , and relies on a differential Cherenkov detector (KTAG) to identify charged kaons at an average rate of 50 MHz in a 750 MHz unseparated hadron beam. The experimental sensitivity of NA62 to K-decay branching ratios (BR) of 10 −11 requires a time resolution for the KTAG of better than 100 ps, an efficiency better than 95% and a contamination of the kaon sample that is smaller than 10 −4 . A prototype version of the detector was tested in 2012, during the first NA62 technical run, in which the required resolution of 100 ps was achieved and the necessary functionality of the light collection system and electronics was demonstrated
Missed opportunities in heart failure diagnosis and management: study of an urban UK population
No full textAbstract Aims This study aimed to examine the diagnostic pathways and outcomes of patients with heart failure (HF), stratified by left ventricular ejection fraction (EF), and to highlight deficiencies in real‐world HF diagnosis and management. Methods and results We conducted a retrospective cohort study in Salford, United Kingdom, utilizing linked primary and secondary care data for HF patients diagnosed between January 2010 and November 2019. We evaluated characteristics, diagnostic patterns, healthcare resource utilization, and outcomes. Patients were categorized according to baseline (the latest measure prior to or within 90 days post‐diagnosis) as having HF with reduced EF (HFrEF), mildly reduced EF (HFmrEF), or preserved EF (HFpEF). The data encompassed a 2 year period before diagnosis and up to 5 years post‐diagnosis. A total of 3227 patients were diagnosed with HF between January 2010 and November 2019. The mean follow‐up time was 2.6 [±1.9 standard deviation (SD)] years. The mean age at diagnosis was 74.8 (±12.7 SD) years, and 1469 (45.5%) were female. HFpEF was the largest cohort (46.6%, npEF = 1505), HFmrEF constituted 16.1% (nmrEF = 520), and HFrEF 18.5% (nrEF = 596) of the population, while 18.8% (nu = 606) of patients remained unassigned due to insufficient evidence to support categorization. At baseline, measurement of natriuretic peptide (NP; brain NP and N‐terminal pro‐B‐type NP) and echocardiographic report data were available for 592 (18.3%) and 2621 (81.2%) patients, respectively. A total of 2099 (65.0%) of the HF cohort had access to a cardiology‐led outpatient clinic prior to the HF diagnosis, and 602 (18.7%) attended cardiac rehabilitation post‐diagnosis. The 5 year crude survival rate was 37.8% [95% confidence interval (CI) (35.2–40.7%)], 42.3% [95% CI (38.0–47.2%)], and 45.5% [95% CI (41.0–50.4%)] for HFpEF, HFrEF, and HFmrEF, respectively. Conclusions Low survival rates were observed across all HF groups, along with suboptimal rates of NP testing and specialist assessments. These findings suggest missed opportunities for timely and accurate HF diagnosis, a pivotal first step in improving outcomes for HF patients. Addressing these gaps in diagnosis and management is urgently needed
First search for K <sup>+</sup> →π <sup>+</sup> νν̅ using the decay-in-flight technique
No full text The NA62 experiment at the CERN SPS reports the first search for K + →π + νν̅ using the decay-in-flight technique, based on a sample of 1.21×10 11 K + decays collected in 2016. The single event sensitivity is 3.15×10 −10 , corresponding to 0.267 Standard Model events. One signal candidate is observed while the expected background is 0.152 events. This leads to an upper limit of 14×10 −10 on the K + →π + νν̅ branching ratio at 95% CL. </p
Search for production of an invisible dark photon in decays
No full textThe results of a search for π decays to a photon and an invisible massive dark photon at the NA62 experiment at the CERN SPS are reported. From a total of 4.12 × 10 tagged π mesons, no signal is observed. Assuming a kinetic-mixing interaction, limits are set on the dark photon coupling to the ordinary photon as a function of the dark photon mass, improving on previous searches in the mass range 60–110 MeV/c. The present results are interpreted in terms of an upper limit of the branching ratio of the electro-weak decay , improving the current limit by more than three orders of magnitude.The results of a search for decays to a photon and an invisible massive dark photon at the NA62 experiment at the CERN SPS are reported. From a total of tagged mesons, no signal is observed. Assuming a kinetic-mixing interaction, limits are set on the dark photon coupling to the ordinary photon as a function of the dark photon mass, improving on previous searches in the mass range 60--110 MeV/. The present results are interpreted in terms of an upper limit of the branching ratio of the electro-weak decay , improving the current limit by more than three orders of magnitude
A measurement of the decay
No full textA sample of candidates with negligible background was collected by the NA62 experiment at the CERN SPS in 2017-2018. The model-independent branching fraction is measured to be , a factor three more precise than previous measurements. The decay form factor is presented as a function of the squared dimuon mass. A measurement of the form factor parameters and their uncertainties is performed using a description based on Chiral Perturbation Theory at .A sample of 2.8 × 10K → πμμ candidates with negligible background was collected by the NA62 experiment at the CERN SPS in 2017–2018. The model-independent branching fraction is measured to be (9.15 ± 0.08) × 10, a factor three more precise than previous measurements. The decay form factor is presented as a function of the squared dimuon mass. A measurement of the form factor parameters and their uncertainties is performed using a description based on Chiral Perturbation Theory at (p).A sample of 2.8 × 10K → πμμ candidates with negligible background was collected by the NA62 experiment at the CERN SPS in 2017–2018. The model-independent branching fraction is measured to be (9.15 ± 0.08) × 10, a factor three more precise than previous measurements. The decay form factor is presented as a function of the squared dimuon mass. A measurement of the form factor parameters and their uncertainties is performed using a description based on Chiral Perturbation Theory at (p)
Searches for lepton number violating decays
No full textThe NA62 experiment at CERN reports a search for the lepton number violating decays and using a data sample collected in 2017. No signals are observed, and upper limits on the branching fractions of these decays of and are obtained, respectively, at 90\% confidence level. These upper limits improve on previously reported measurements by factors of 3 and 2, respectively.The NA62 experiment at CERN reports a search for the lepton number violating decays K+→π−e+e+ and K+→π−μ+μ+ using a data sample collected in 2017. No signals are observed, and upper limits on the branching fractions of these decays of 2.2×10−10 and 4.2×10−11 are obtained, respectively, at 90% confidence level. These upper limits improve on previously reported measurements by factors of 3 and 2, respectively.The NA62 experiment at CERN reports a search for the lepton number violating decays and using a data sample collected in 2017. No signals are observed, and upper limits on the branching fractions of these decays of and are obtained, respectively, at 90% confidence level. These upper limits improve on previously reported measurements by factors of 3 and 2, respectively
