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

Comparison of the proliferation potential and neurotrophic factors expression in the adherent neural stem cells culture of the Subgranular, Subventricular zone and the central canal of the spinal cord of the adult rats

Background and Objective: Degeneration of neurons in the central nervous system occurs during aging. Transplantation of neural stem cells (NSCs) can be preventing the degeneration of neurons. In addition to neuronal replacement, with the production of neurotrophic factors, increased survival and proliferation of endogenous cells. This study was done to compare the cell proliferation, neurotrophic factors expression and features of NSCs harvested from different areas of the central nervous system in vitro. Materials and Methods: In this laboratory study NSCs have been harvested from subgranular zone (SGZ), subventricular zone (SVZ) and central canal of spinal cord from adult Wistar rats with mechanical, enzymatical digestion and subsequently was cultured in α-MEM medium supplemented with serum as monolayer or adherent conditions and passaged for 13 times. Immunocytochemistry was used to determine expression of the nestin and GFAP markers. Semi-quantitative RT–PCR was used to confirm genes expression (NGF, CNTF, NT3, NT4/5, GDNF and BDNF). Results: Morphological features of stem cells extracted from different regions of the central nervous system were similar in the culture. Doubling time NSCs in the SVZ (37.45 hr) is shorter than in the SGZ (44.04 hr) and central canal of spinal cord (57.22 hr). The culture conditions as well as monolayer neural stem cells are capable of producing neurospheres. Also, nestin and GFAP markers, expressed by NSCs. Neurotrophic gene expression pattern profiles were similar to each other in stem cells extracted from the SGZ, SVZ and central canal of spinal cord. Conclusion: Neurotrophic gene expression in stem cells extracted from different regions of the central nervous system were similar, but proliferation capacity was higher in NSCs, which have been harvested from the SVZ

Inductive effect of Deprenyl and Dimethyl sulfoxide on proliferation and survival of the mesenchymal stem cells

Background and Objective: Research have been focused on the applying the chemical inducer for trans-differentiation the adult BMSCs into neural cell. So that, at the first should investigate the toxcity effect of the chemical inducer on the induced cells. Plasticity and easy accessibility of bone marrow mesenchymal stem cells is a unique charactristic for treatment of neural disorderies. This study was desgined to determine the inductive effect of Deprenyl and Dimethyl sulfoxide on proliferation and survival of the mesenchymal stem cells. Materials and Methods: In this experimental study, BMSCs isolated from the adult rat bone marrow and cultured in αMEM containing 10% FBS. Cell identity for surface antigens was performed in third passage by immunocytochemistry and multipotancy capacity of BMSCs was done by BMSC differentiation into adipocytes and osteocytes. The cells were exposed to chemical agents (a: the αMEM medium supplemented with 2% DMSO, b: the αMEM medium supplemented with 10-8M Deprenyl) for 24 houres and then transferred to αMEM containing 10% FBS cell survival and proliferation was evaluated after the 24, 48, 72 and 96 houres by MTT [3-(4-5-Dimethylthiazolyl-2-y1)-2,5-diphenyltetrazolium bromid] test. Data were analyzed using SPSS-16, One-Way ANOVA and Tukey tests. Results: In addition to expression the surface antigens and adipogenic and osteogenic differentiation by BMSCs, MTT test results showed that proliferation and survival of induced-deprenyl and DMSO cells within 48, 72 and 96 hours after the induction was increased significantly than negative control group. Conclusion: Deprenyl increases survival and cell proliferation compared to Dimethyl Sulfoxide. It can be used as cell inducer

Assessment of neurotrophic factors expression and cell proliferation in the coculture of neural and mesenchymal stem cells

Background and Objective: Neurotrophic factors are diffusible polypeptides that have critical roles in survival, proliferation and differentiation of stem cells. This study was done to assess the role of neurotrophic factors (CNTF‎, BDNF, ‎GDN‎F, ‎NT-‎3‎) expression and proliferation rate of neural stem cells (NSCs) in coculture with mesenchymal stem cells (MSCs). Materials and Methods: In this experimental study, NSCs and MSCs were isolated from adult Wistar rat. Initially, NSCs was harvested from temporal lobe after mechanical digestion by a sterile flamed Pasteur pipette and enzymatic digestion with trypsin and Dnase. The cell suspension was cultivated in a flask with DMEM/F12 medium supplemented with 10% FBS 100U/ml Penicillin and 100 mg/ml Streptomycin. To obtain MSCs, bone marrow of femur and tibia bones were flashed out and cultured. MSCs and NSCs‎ cocultured by transwell ‎system in DMEM/F12 medium supplemented with 10% FBS 100U/ml Penicillin and 100 mg/ml Streptomycin. Haemocytometer, immunocytochemistry and RT-PCR methods were performed to identify and evaluate cell proliferation, purity levels and neurotrophic factors expression. Results: There ‎is‎ no differences in NTFs profile of ‎neurotrophic‎ factors expression between ‎coculture ‎group‎ ‎and‎ control ‎NSCs, but interactions between MSCs and NSCs significantly promoted NSCs proliferation (P<0.05). Conclusion: This study showed that coculture of NSCs with MSCs might be prfered in cell-therapy than‎ NSCs.