First observation of Z boson plus two jet production

Events with jets produced in association with a Z boson in proton-proton collisions can be used to study distributions sensitive to the vector boson fusion (VBF) process at CERN's Large Hadron Collider. This process is interesting to study because of its similarity to the VBF production of a Higgs boson as well as its sensitivity to new physics via the WWZ triple gauge coupling. Evidence for electroweak Zjj production beyond the 5 level is presented using data collected at a centre-of-mass energy of \sqrt{s} = 8 TeV by the ATLAS experiment in 2012. This constitutes the first observation of a VBF-like process. The detector-corrected cross sections measured in two fi ducial regions are in excellent agreement with the Standard Model expectations and have also been used to constrain anomalous triple gauge couplings. Furthermore, detector-corrected cross sections and diff erential distributions for inclusive Zjj production are presented in di fferent regions of phase space with varying sensitivity to the electroweak Zjj component. In addition, a performance study of the tracking algorithms used in the ATLAS high-level trigger system is presented

Surgical therapy of celiac axis and superior mesenteric artery syndrome

INTRODUCTION Compression syndromes of the celiac artery (CAS) or superior mesenteric artery (SMAS) are rare conditions that are difficult to diagnose; optimal treatment remains complex, and symptoms often persist after surgery. We aim to review the literature on surgical treatment and postoperative outcome in CAS and SMAS syndrome. METHODS A systematic literature review of medical literature databases on the surgical treatment of CAS and SMAS syndrome was performed from 2000 to 2022. Articles were included according to PROSPERO guidelines. The primary endpoint was the failure-to-treat rate, defined as persistence of symptoms at first follow-up. RESULTS Twenty-three studies on CAS (n = 548) and 11 on SMAS (n = 168) undergoing surgery were included. Failure-to-treat rate was 28% for CAS and 21% for SMAS. Intraoperative blood loss was 95 ml (0-217) and 31 ml (21-50), respectively, and conversion rate was 4% in CAS patients and 0% for SMAS. Major postoperative morbidity was 2% for each group, and mortality was described in 0% of CAS and 0.4% of SMAS patients. Median length of stay was 3 days (1-12) for CAS and 5 days (1-10) for SMAS patients. Consequently, 47% of CAS and 5% of SMAS patients underwent subsequent interventions for persisting symptoms. CONCLUSION Failure of surgical treatment was observed in up to every forth patient with a high rate of subsequent interventions. A thorough preoperative work-up with a careful patient selection is of paramount importance. Nevertheless, the surgical procedure was associated with a beneficial risk profile and can be performed minimally invasive

Pre-Emptive Endoluminal Negative Pressure Therapy at the Anastomotic Site in Minimally Invasive Transthoracic Esophagectomy (the preSPONGE Trial): Study Protocol for a Multicenter Randomized Controlled Trial

Introduction: Anastomotic leakage (AL) accounts for a significant proportion of morbidity following oesophagectomy. Endoluminal negative pressure (ENP) therapy via a specifically designed polyurethane foam (EsoSponge®, B.Braun Medical, Melsungen, Germany) has become the standard of care for AL in many specialized centres. The prophylactic (pENP) application of this technique aims to reduce postoperative morbidity and is a novel approach which has not yet been investigated in a prospective study. The aim of this study is therefore to assess the effect of pENP at the anastomotic site in high-risk patients undergoing minimally invasive transthoracic Ivor Lewis oesophagectomy. Methods and analysis: The study design is a prospective, multi-centre, two-arm, parallel-group, randomised controlled trial and will be conducted in two phases. Phase one is a randomised feasibility and safety pilot trial involving 40 consecutive patients. After definitive sample size calculation, additional patients will be included accordingly during phase two. The primary outcome of the study will be the postoperative length of hospitalization until reaching previously defined “fit for discharge criteria”. Secondary outcomes will include postoperative morbidity, mortality and postoperative AL-rates based on 90-day follow-up. A confirmatory analysis based on intention-to-treat will be performed. Ethics and dissemination: The ethics committee of the University of Zurich approved this study (2019-00562), which has been registered with ClinicalTrials.gov on 14.11.2019 (NCT04162860) and the Swiss National Clinical Trials Portal (SNCTP000003524). The results of the study will be published and presented at appropriate conferences

Regulation of TMPRSS6 by BMP6 and iron in human cells and mice.

Mutations in transmembrane protease, serine 6 (TMPRSS6), encoding matriptase-2, are responsible for the familial anemia disorder iron-refractory iron deficiency anemia (IRIDA). Patients with IRIDA have inappropriately elevated levels of the iron regulatory hormone hepcidin, suggesting that TMPRSS6 is involved in negatively regulating hepcidin expression. Hepcidin is positively regulated by iron via the bone morphogenetic protein (BMP)-SMAD signaling pathway. In this study, we investigated whether BMP6 and iron also regulate TMPRSS6 expression. Here we demonstrate that, in vitro, treatment with BMP6 stimulates TMPRSS6 expression at the mRNA and protein levels and leads to an increase in matriptase-2 activity. Moreover, we identify that inhibitor of DNA binding 1 is the key element of the BMP-SMAD pathway to regulate TMPRSS6 expression in response to BMP6 treatment. Finally, we show that, in mice, Tmprss6 mRNA expression is stimulated by chronic iron treatment or BMP6 injection and is blocked by injection of neutralizing antibody against BMP6. Our results indicate that BMP6 and iron not only induce hepcidin expression but also induce TMPRSS6, a negative regulator of hepcidin expression. Modulation of TMPRSS6 expression could serve as a negative feedback inhibitor to avoid excessive hepcidin increases by iron to help maintain tight homeostatic balance of systemic iron levels

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations

Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector

The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +c¯¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯¯¯ quark asymmetry

Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30