The production of a $W$ boson in association with a single charm quark is studied using 140 fb–1 of $\sqrt{s}$ = $13$ $\mathrm{TeV}$ proton-proton collision data collected with the ATLAS detector at ...the Large Hadron Collider. The charm quark is tagged by the presence of a charmed hadron reconstructed with a secondary-vertex fit. The $W$ boson is reconstructed from the decay to either an electron or a muon and the missing transverse momentum present in the event. The charmed mesons reconstructed are D+ → K– π+ π+ and D*+ → D0 π+ → (K– π+) π+ and the charge conjugate decays in the fiducial regions where $p$T($e,μ$) > 30 GeV, |$η(e,μ)$| < 2.5, $p$T (D(*)) > 8 GeV, and |$η$(D(*))| < 2.2. The integrated and normalized differential cross sections as a function of the pseudorapidity of the lepton from the $W$ boson decay, and of the transverse momentum of the charmed hadron, are extracted from the data using a profile likelihood fit. The measured total fiducial cross sections are ${σ}_{fid}^{OS – SS}$ (W– + D+) = 50.2 ± 0.2 ${(stat)}_{–2.3}^{+2.4}$(syst) pb, ${σ}_{fid}^{OS – SS}$ (W+ + D–) = 48.5 ± 0.2 ${(stat)}_{–2.2}^{+2.3}$(syst) pb, ${σ}_{fid}^{OS – SS}$ (W– + D*+) = 51.1 ± 0.4 ${(stat)}_{–1.8}^{+1.9}$(syst) pb, ${σ}_{fid}^{OS – SS}$ (W+ + D*–) = 50.0 ± 0.4 ${(stat)}_{–1.8}^{+1.9}$(syst) pb. Results are compared with the predictions of next-to-leading-order quantum chromodynamics calculations performed using state-of-the-art parton distribution functions. Additionally, the ratio of charm to anticharm production cross sections is studied to probe the $s$-$\bar{s}$ quark asymmetry. The ratio is found to be ${R}_{c}^{±}$= 0.971 ± 0.006 (stat) ± 0.011 (syst). The ratio and cross-section measurements are consistent with the predictions obtained with parton distribution function sets that have a symmetric $s$-$\bar{s}$ sea, indicating that any $s$-$\bar{s}$ asymmetry in the Bjorken-x region relevant for this measurement is small.
A measurement of W± boson production in Pb+Pb collisions at √sNN=5.02 TeV is reported using data recorded by the ATLAS experiment at the LHC in 2015, corresponding to a total integrated luminosity of ...0.49nb-1. The W± bosons are reconstructed in the electron or muon leptonic decay channels. Production yields of leptonically decaying W± bosons, normalised by the total number of minimum-bias events and the nuclear thickness function, are measured within a fiducial region defined by the detector acceptance and the main kinematic requirements. These normalised yields are measured separately for W+ and W- bosons, and are presented as a function of the absolute value of pseudorapidity of the charged lepton and of the collision centrality. The lepton charge asymmetry is also measured as a function of the absolute value of lepton pseudorapidity. In addition, nuclear modification factors are calculated using the W± boson production cross-sections measured in pp collisions. The results are compared with predictions based on next-to-leading-order calculations with CT14 parton distribution functions as well as with predictions obtained with the EPPS16 and nCTEQ15 nuclear parton distribution functions. No dependence of normalised production yields on centrality and a good agreement with predictions are observed for mid-central and central collisions. For peripheral collisions, the data agree with predictions within 1.7 (0.9) standard deviations for W- (W+) bosons.
A search for a narrow scalar resonance decaying into an opposite-sign muon pair produced in events with and without b-tagged jets is presented in this paper. The search uses 36.1 fb-1 of $ ...\sqrt{s}=13 $ TeV proton-proton collision data recorded by the ATLAS experiment at the LHC. No significant excess of events above the expected Standard Model background is observed in the investigated mass range of 0.2 to 1.0 TeV. The observed upper limits at 95% confidence level on the cross section times branching ratio for b-quark associated production and gluon-gluon fusion are between 1.9 and 41 fb and 1.6 and 44 fb respectively, which is consistent with expectations. Figure not available: see fulltext..
A search for excited electrons produced in pp collisions at $\sqrt{s}$ = 13 TeV via a contact interaction $q\overline{q}$ → ee* is presented. The search uses 36.1 fb-1 of data collected in 2015 and ...2016 by the ATLAS experiment at the Large Hadron Collider. Decays of the excited electron into an electron and a pair of quarks ($eq\overline{q}$) are targeted in final states with two electrons and two hadronic jets, and decays via a gauge interaction into a neutrino and a W boson (νW) are probed in final states with an electron, missing transverse momentum, and a large-radius jet consistent with a hadronically decaying W boson. No significant excess is observed over the expected backgrounds. Upper limits are calculated for the pp→ ee*→$eeq\overline{q}$ and pp→ ee*→ eνW production cross sections as a function of the excited electron mass $m_{e*}$ at 95% confidence level. The limits are translated into lower bounds on the compositeness scale parameter Λ of the model as a function of $m_{e*}$. For $m_{e*}$ <0.5 TeV, the lower bound for Λ is 11 TeV. In the special case of $m_{e*}$=Λ, the values of $m_{e*}$< 4.8 TeV are excluded. The presented limits on Λ are more stringent than those obtained in previous searches.
Abstract
Introduction
Selective optogenetic stimulation of basal forebrain (BF) neuronal subtypes, Cholinergic (ChAT+), vesicular glutamate transporter2-expressing glutamatergic (vGluT2+) and ...parvalbumin-expressing GABAergic (PV+), causes arousal. However, it is unclear if they are equally effective in eliciting a homeostatic sleep response (HSR). The importance of interactions between these cell-types in the HSR has not previously been investigated. Thus, we used optogenetics and reverse microdialysis of pharmacological agents to investigate these questions.
Methods
C57BL/6 (WT) mice were sleep deprived (6h) with and without reverse microdialysis of cholinergic antagonists into BF. The amount of recovery sleep and delta activity (0.5–4.5Hz) were used as the markers of HSR. In ChAT-Cre, vGluT2-Cre, PV-Cre transgenic mice transduced with AAV-ChR2-EYFP in BF, we examined the effect of 6h laser (473nm) illuminations (5s/min, 10 Hz for ChAT+ and vGluT2+, 40Hz for PV+) on HSR, during the 2h poststimulation period and compared it with time matched sham stimulation (BL, TTLpulse without laser). In ChAT-Cre mice we performed optodialysis of cholinergic antagonists during 6h optical stimulation and examined the post stimulation HSR.
Results
In WT mice (n=4) microdialysis of cholinergic antagonists did not prevent HSR, as evaluated by an increase in sleep time (36%) and delta power (8.14%, p<0.001). Optogenetic stimulation of ChAT+ neurons (N=3), led to an increase in sleep (BL 52.6 ± 0.56 vs poststim 57 ± 2.88) and delta by 24% during the 2h poststimulation compared to BL, that was not blocked by cholinergic antagonist. In contrast, GABA/PV+ neuronal stimulation did not cause HSR. Optogenetic stimulation of vGluT2+ neurons in 1 mouse, showed a tendency towards HSR.
Conclusion
Preliminary results suggest that ChAT+ and vGluT2+, but not PV+ neurons, are involved in mediating HSR. Furthermore, local effects of acetylcholine on non-ChAT+ neurons are not required for HSR. These results, together with previous cholinergic lesion studies, suggest a model whereby direct or indirect excitation of ChAT+ neurons (via vGluT2+ neurons) is key to trigger HSR.
Support (If Any)
VA I01BX001404, I01BX001356, I01BX002774, IK2BX002130, NIH R21NS079866, R01MH039683, P01HL095491, R01MH099180, R03-MH107650. JTM received partial salary from Merck MISP, no COI with this work.
In this study, zinc oxide (ZnO) and aluminium doped zinc oxide (ZnO:Al) thin films were deposited by reactive chemical pulverization spray pyrolysis technique on heated glass substrates at 450degC. ...X-ray diffraction (XRD), scanning electron microscopy (SEM) and third harmonic generation (THG) are used to characterize their structure , morphology and nonlinear optical properties as a function of Al concentration (0, 3, 5, 7 at %). The intensity of third order non linear optical susceptibility increase by incorporation of aluminium. A strong value of susceptibility chi (3) was found for films with a good crystallinity.
The authors report on a study carried out in the University Clinic of Gynaecology and Obstetrics in Rabat on 13 cases of anencephaly without hydramnios in which post-maturity occurred. This gives ...them an opportunity of pointing out: --that there is a raised level of anencephaly in Morocco: --that the male sex is more commonly affected with anencephaly associated with post-maturity. And they wish to go through: --the physiological theories that are concerned with the role of the fetus in the onset of labour: --and the screening that has become possible since ultrasound and estimation of alpha-feto-protein levels have been in use, and that these should be used systematically in all pregnant women before they deliver an infant with a central nervous system malformation.
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