Measurement and interpretation of same-sign W boson pair production in association with two jets in pp collisions at s = 13 TeV with the ATLAS detector

This paper presents the measurement of fducial and diferential cross sections for both the inclusive and electroweak production of a same-sign W-boson pair in association with two jets (W±W±jj) using 139 fb−1 of proton-proton collision data recorded at a centre-of-mass energy of √s = 13 TeV by the ATLAS detector at the Large Hadron Collider. The analysis is performed by selecting two same-charge leptons, electron or muon, and at least two jets with large invariant mass and a large rapidity diference. The measured fducial cross sections for electroweak and inclusive W±W±jj production are 2.92 ± 0.22 (stat.) ± 0.19 (syst.)fb and 3.38±0.22 (stat.)±0.19 (syst.)fb, respectively, in agreement with Standard Model predictions. The measurements are used to constrain anomalous quartic gauge couplings by extracting 95% confdence level intervals on dimension-8 operators. A search for doubly charged Higgs bosons H±± that are produced in vector-boson fusion processes and decay into a same-sign W boson pair is performed. The largest deviation from the Standard Model occurs for an H±± mass near 450 GeV, with a global signifcance of 2.5 standard deviations

Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at s = 13 TeV with the ATLAS detector

A combination of searches for new heavy spin-1 resonances decaying into different pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, , and tb) or third-generation leptons (τν and ττ) are included in this kind of combination for the first time. A simplified model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confidence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion

Search for dark photons in rare Z boson decays with the ATLAS detector

A search for events with a dark photon produced in association with a dark Higgs boson via rare decays of the standard model Z boson is presented, using 139     fb − 1 of √ s = 13     TeV proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider. The dark boson decays into a pair of dark photons, and at least two of the three dark photons must each decay into a pair of electrons or muons, resulting in at least two same-flavor opposite-charge lepton pairs in the final state. The data are found to be consistent with the background prediction, and upper limits are set on the dark photon’s coupling to the dark Higgs boson times the kinetic mixing between the standard model photon and the dark photon, α D ϵ 2 , in the dark photon mass range of [5, 40] GeV except for the Υ mass window [8.8, 11.1] GeV. This search explores new parameter space not previously excluded by other experiments

Combined measurement of the Higgs boson mass from the H → γγ and H → ZZ∗ → 4ℓ decay channels with the ATLAS detector using √s = 7, 8, and 13 TeV pp collision data

A measurement of the mass of the Higgs boson combining the H → Z Z ∗ → 4 ℓ and H → γ γ decay channels is presented. The result is based on 140     fb − 1 of proton-proton collision data collected by the ATLAS detector during LHC run 2 at a center-of-mass energy of 13 TeV combined with the run 1 ATLAS mass measurement, performed at center-of-mass energies of 7 and 8 TeV, yielding a Higgs boson mass of 125.11 ± 0.09 ( stat ) ± 0.06 ( syst ) = 125.11 ± 0.11     GeV . This corresponds to a 0.09% precision achieved on this fundamental parameter of the Standard Model of particle physics

Letter to the Editor - Neonatal Adrenal Haemorrhagic Pseudocyst

A seven days old male neonate born to a diabetic mother (mild gestational diabetes) at term after an uncomplicated pregnancy with a birth weight of 3000gms, presented with a left sided flank mass. The neonate was otherwise asymptomatic. Standard laboratory tests were unremarkable. Ultrasound revealed a non-homogenous cystic mass lesion 3.9cm x 3.2cm at the upper pole of left kidney. Spiral un-enhanced computerised tomographic (CT) scan revealed a left renal mass measuring about 5 cm x 4.2cm x 6.5cm.The right kidney was essentially normal. Nuclear scan revealed an area of photopenia seen in the upper pole of the left kidney probably due to tumour as noted previously on the CT scan. This had displaced the left kidney slightly inferiorly. The right kidney had a normal configuration. The provisional diagnosis was made as congenital neuroblastoma. Surgical exploration was decided upon to exclude malignancy. At laparotomy, the right kidney was normal to palpate. Liver was normal. The left kidney showed foetal lobulations. A cystic mass was palpated in close proximity to the upper pole of the left kidney with no plane between the mass and the renal capsule. With a strong suspicion of malignancy, a radical left nephrectomy was done. Postoperative course was uneventful. Final histopathology revealed adrenal haemorrhagic pseudocyst, fetal lobulations of the left kidney with normal renal parenchymal structures

Total internal biliary diversion during liver transplantation for type 1 progressive familial intrahepatic cholestasis: a novel approach

LT for PFIC type 1 is often complicated by postoperative diarrhea and recurrent graft steatosis. A 26-month-old female child with cholestatic jaundice, pruritus, diarrhea, and growth retardation revealed total bilirubin 9.1 mg/dL, gamma-glutamyl transpeptidase 64 IU/L, and TBA 295.8 μmol/L. Genetic analysis confirmed ATP8B1 defects. A LT (segment 2, 3 graft) from the heterozygous father was performed. Biliary diversion was performed by a 35-cm jejunum conduit between the graft hepatic duct and the mid-transverse colon. Stools became pigmented immediately. Follow-up at 138 days revealed resolution of jaundice and pruritus and soft-to-hard stools (6-8 daily). Radioisotope hepato-biliary scintigraphy (days 26, 68, and 139) confirmed unobstructed bile drainage into the colon (t1/2 34, 27, and 19 minutes, respectively). Contrast meal follow-through at day 62 confirmed the absence of any colo-jejuno-hepatic reflux. At 140 days, contrast follow-through via the biliary stent revealed patent jejuno-colonic anastomosis and satisfactory transit. Graft biopsy at LT, 138 days, and 9 months follow-up revealed comparable grades of macrovesicular steatosis (<20%). TIBD during LT may be a clinically effective stoma-free biliary diversion and may prevent recurrent graft steatosis following LT for PFIC type 1