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

Valutazione della risposta ai sali di litio in pazienti sardi affetti da disturbo bipolare = Evaluation of lithium treatment response in Sardinian bipolar patients

Scopo. Il disturbo bipolare (BP) è un disturbo ciclico dell’umore che ha una prevalenza dell’1-2% nella popolazione generale. Il trattamento a lungo termine prevede l’utilizzo dei farmaci stabilizzanti, tra cui il litio rappresenta la prima scelta. L’obiettivo di questo studio è valutare, nell’ambito di un setting naturalistico, l’effectiveness del trattamento con litio, ed evidenziare l’eventuale associazione tra alcuni marker clinici e una migliore o peggiore risposta alla terapia. Metodi. Sono stati studiati 199 pazienti ambulatoriali affetti da BP (secondo i criteri del DSM-IV) in terapia con litio per almeno un anno consecutivo. Il decorso clinico di ciascun paziente è stato rappresentato graficamente tramite il metodo della NIMH Life Chart, a cui è stata applicata la Retrospective Evaluation of Prophylactic Treatment Response Scale. Questa scala valuta la risposta alla terapia stabilizzante discriminando se un eventuale miglioramento sia dovuto effettivamente all’effetto del farmaco in studio o ad altri fattori. Risultati. Il 29% dei pazienti del campione ha raggiunto una risposta completa (Full Responder) alla terapia con litio. La diagnosi di BPII si associa significativamente a una buona risposta (p=0,035), mentre la psicosi è la variabile che si associa in maniera più significativa a una peggiore risposta alla suddetta terapia (p=0,0197). Conclusioni. Questo studio conferma l’effectiveness del litio nel trattamento preventivo del BP, suggerendo che anche i pazienti con BPII potrebbero trarne beneficio. Infine, i nostri risultati indicano che la terapia di combinazione o con altro stabilizzante dell’umore potrebbe rappresentare una valida opzione nella gestione clinica dei pazienti che presentano psicosi.Aim. Bipolar disorder (BP) is a mood disorder with a prevalence of 1-2% in the general population. Lithium is the most widely used and best characterized long-term treatment for BP.The aim of this study is the evaluation of the effectiveness of lithium treatment in a naturalistic setting. Moreover we investigated if a number of clinical markers were positively or negatively associated with treatment response. Methods. We evaluated 199 outpatients affected by BP (according to DSM-IV criteria), who had continuously received lithium for at least one year. Life course of illness in each patient was graphically depicted with the NIMH Life Chart method which allowed us to apply the Retrospective Evaluation of Prophylactic Treatment Response Scale in order to assess the treatment outcome.This scale rates the degree of improvement in the course of treatment weighted by the likelihood of response being attributable to the treatment, rather than other factors. Results. Full Responders to lithium were 29% of the sample. Bipolar II (BPII) patients were significantly overrepresented in the Full Responders group (p=0,035). In addition, psychotic symptoms were significantly associated to a poorer treatment outcome (p=0,0197). Conclusions. This study supports the effectiveness of lithium treatment in a naturalistic setting, suggesting that BPII patients could also benefit from lithium treatment. Finally, it suggests that the use of another mood stabilizer or of a combination treatment could represent a valuable therapeutic choice in the management of bipolar patients with psychotic symptoms