79 research outputs found

    Does stimulant therapy help adult ADHD?

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    Central nervous system stimulants improve symptoms of attention deficit-hyperactivity disorder (ADHD) in adults (strength of recommendation: B, based on an older, inconclusive systematic review, a lesser-quality systematic review, and several newer small randomized controlled trials). Although not the focus of this question, nonstimulant medications (including buproprion, modafinil, and guanfacine) have also been studied in the treatment of ADHD in adults. Recently, atomoxetine became the only nonstimulant medication to receive approval by the US Food and Drug Administration for the treatment of ADHD

    What are effective treatments for oppositional and defiant behaviors in preadolescents?

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    Parent training is effective for treating oppositional and defiant behaviors (strength of recommendation [SOR]: A, based on systematic reviews). Parent training programs are standardized, short-term interventions that teach parents specialized strategies--including positive attending, ignoring, the effective use of rewards and punishments, token economies, and time out --to address clinically significant behavior problems. In addition to parent training, other psychosocial interventions are efficacious in treating oppositional and defiant behavior. To date, no studies have assessed the efficacy of medication in treating children with pure oppositional defiant disorder (ODD). However, studies have shown amphetamines to be effective for children with ODD and comorbid attention deficit/hyperactivity disorder (ADHD) (SOR: A, based on a meta-analysis)

    Search for long-lived particles using displaced vertices and missing transverse momentum in proton-proton collisions at s= \sqrt{s}= 13 TeV

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    A search for the production of long-lived particles in proton-proton collisions at a center-of-mass energy of 13 TeV at the CERN LHC is presented. The search is based on data collected by the CMS experiment in 2016-2018, corresponding to a total integrated luminosity of 137 fb1 ^{-1} . This search is designed to be sensitive to long-lived particles with mean proper decay lengths between 0.1 and 1000 mm, whose decay products produce a final state with at least one displaced vertex and missing transverse momentum. A machine learning algorithm, which improves the background rejection power by more than an order of magnitude, is applied to improve the sensitivity. The observation is consistent with the standard model background prediction, and the results are used to constrain split supersymmetry (SUSY) and gauge-mediated SUSY breaking models with different gluino mean proper decay lengths and masses. This search is the first CMS search that shows sensitivity to hadronically decaying long-lived particles from signals with mass differences between the gluino and neutralino below 100 GeV. It sets the most stringent limits to date for split-SUSY models and gauge-mediated SUSY breaking models with gluino proper decay length less than 6 mm.A search for the production of long-lived particles in proton-proton collisions at a center-of-mass energy of 13 TeV at the CERN LHC is presented. The search is based on data collected by the CMS experiment in 2016–2018, corresponding to a total integrated luminosity of 137  fb-1. This search is designed to be sensitive to long-lived particles with mean proper decay lengths between 0.1 and 1000 mm, whose decay products produce a final state with at least one displaced vertex and missing transverse momentum. A machine learning algorithm, which improves the background rejection power by more than an order of magnitude, is applied to improve the sensitivity. The observation is consistent with the standard model background prediction, and the results are used to constrain split supersymmetry (SUSY) and gauge-mediated SUSY breaking models with different gluino mean proper decay lengths and masses. This search is the first CMS search that shows sensitivity to hadronically decaying long-lived particles from signals with mass differences between the gluino and neutralino below 100 GeV. It sets the most stringent limits to date for split-SUSY models and gauge-mediated SUSY breaking models with gluino proper decay length less than 6 mm.A search for the production of long-lived particles in proton-proton collisions at a center-of-mass energy of 13 TeV at the CERN LHC is presented. The search is based on data collected by the CMS experiment in 2016-2018, corresponding to a total integrated luminosity of 137 fb1^{-1}. This search is designed to be sensitive to long-lived particles with mean proper decay lengths between 0.1 and 1000 mm, whose decay products produce a final state with at least one displaced vertex and missing transverse momentum. A machine learning algorithm, which improves the background rejection power by more than an order of magnitude, is applied to improve the sensitivity. The observation is consistent with the standard model background prediction, and the results are used to constrain split supersymmetry (SUSY) and gauge-mediated SUSY breaking models with different gluino mean proper decay lengths and masses. This search is the first CMS search that shows sensitivity to hadronically decaying long-lived particles from signals with mass differences between the gluino and neutralino below 100 GeV. It sets the most stringent limits to date for split-SUSY models and gauge-mediated SUSY breaking models with gluino proper decay length less than 6 mm

    Search for long-lived particles decaying to final states with a pair of muons in proton-proton collisions at s\sqrt{s} = 13.6 TeV

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    International audienceAn inclusive search for long-lived exotic particles (LLPs) decaying to final states with a pair of muons is presented. The search uses data corresponding to an integrated luminosity of 36.6 fb1^{-1} collected by the CMS experiment from the proton-proton collisions at s\sqrt{s} = 13.6 TeV in 2022, the first year of Run 3 of the CERN LHC. The experimental signature is a pair of oppositely charged muons originating from a common vertex spatially separated from the proton-proton interaction point by distances ranging from several hundred μ\mum to several meters. The sensitivity of the search benefits from new triggers for displaced dimuons developed for Run 3. The results are interpreted in the framework of the hidden Abelian Higgs model, in which the Higgs boson decays to a pair of long-lived dark photons, and of an RR-parity violating supersymmetry model, in which long-lived neutralinos decay to a pair of muons and a neutrino. The limits set on these models are the most stringent to date in wide regions of lifetimes for LLPs with masses larger than 10 GeV

    Observation of the J/ψμ+μμ+μ {\mathrm{J}/\psi} \to\mu^{+}\mu^{-}\mu^{+}\mu^{-} decay in proton-proton collisions at s= \sqrt{s} = 13 TeV

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    The J/ψμ+μμ+μ {\mathrm{J}/\psi} \to\mu^{+}\mu^{-}\mu^{+}\mu^{-} decay has been observed with a statistical significance in excess of five standard deviations. The analysis is based on an event sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment in 2018 and corresponding to an integrated luminosity of 33.6 fb1 ^{-1} . Normalizing to the J/ψμ+μ {\mathrm{J}/\psi} \to\mu^{+}\mu^{-} decay mode leads to a branching fraction of [ [ 10.1 2.7+3.3 ^{+3.3}_{-2.7} (stat) ±\pm 0.4 (syst) ]×] \times 107^{-7}, a value that is consistent with the standard model prediction.The J/ψ→μ+μ-μ+μ- decay has been observed with a statistical significance in excess of five standard deviations. The analysis is based on an event sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment in 2018 and corresponding to an integrated luminosity of 33.6  fb-1. Normalizing to the J/ψ→μ+μ- decay mode leads to a branching fraction of [10.1-2.7+3.3(stat)±0.4(syst)]×10-7, a value that is consistent with the standard model prediction.The J/ψ\psi\toμ+μμ+μ\mu^+\mu^-\mu^+\mu^- decay has been observed with a statistical significance in excess of five standard deviations. The analysis is based on an event sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment in 2018 and corresponding to an integrated luminosity of 33.6 fb1^{-1}. Normalizing to the J/ψ\psi\toμ+μ\mu^+\mu^- decay mode leads to a branching fraction [10.1 2.7+3.3^{+3.3}_{-2.7} (stat) ±\pm 0.4 (syst)] ×\times 107^{-7}, a value that is consistent with the standard model prediction

    Observation of the Ξb\Xi^-_\mathrm{b}\toψ\psi(2S)Ξ\Xi^- decay and studies of the Ξb0\Xi_\mathrm{b}^{\ast{}0} baryon in proton-proton collisions at s\sqrt{s} = 13 TeV

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    International audienceThe first observation of the decay Ξb\Xi^-_\mathrm{b}\toψ\psi(2S)Ξ\Xi^- and measurement of the branching ratio of Ξb\Xi^-_\mathrm{b}\toψ\psi(2S)Ξ\Xi^- to Ξb\Xi^-_\mathrm{b}\to J/ψ\psiΞ\Xi^- are presented. The J/ψ\psi and ψ\psi(2S) mesons are reconstructed using their dimuon decay modes. The results are based on proton-proton colliding beam data from the LHC collected by the CMS experiment at s\sqrt{s} = 13 TeV in 2016-2018, corresponding to an integrated luminosity of 140 fb1^{-1}. The branching fraction ratio is measured to be B\mathcal{B}(Ξb\Xi^-_\mathrm{b}\toψ\psi(2S)Ξ\Xi^-)/B\mathcal{B}(Ξb\Xi^-_\mathrm{b}\to J/ψ\psiΞ\Xi^-) = 0.840.19+0.21^{+0.21}_{-0.19} (stat) ±\pm 0.10 (syst) ±\pm 0.02 (B\mathcal{B}), where the last uncertainty comes from the uncertainties in the branching fractions of the charmonium states. New measurements of the Ξb0\Xi_\mathrm{b}^{\ast{}0} baryon mass and natural width are also presented, using the Ξbπ+\Xi_\mathrm{b}^-\pi^+ final state, where the Ξb\Xi^-_\mathrm{b} baryon is reconstructed through the decays J/ψΞ\psi \Xi^-, ψ\psi(2S)Ξ\Xi^-, J/ψΛ\psi \LambdaK^-, and J/ψΣ0\psi \Sigma^0K^-. Finally, the fraction of the Ξb\Xi^-_\mathrm{b} baryons produced from Ξb0\Xi_\mathrm{b}^{\ast{}0} decays is determined

    Search for the decay of the Higgs boson to a pair of light pseudoscalar bosons in the final state with four bottom quarks in proton-proton collisions at s\sqrt{s} = 13 TeV

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    International audienceA search is presented for the decay of the 125 GeV Higgs boson (H) to a pair of new light pseudoscalar bosons (a), followed by the prompt decay of each a boson to a bottom quark-antiquark pair, H \to aa \tobbˉbbˉ\mathrm{b\bar{b}b\bar{b}}. The analysis is performed using a data sample of proton-proton collisions collected with the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb1^{-1}. To reduce the background from standard model processes, the search requires the Higgs boson to be produced in association with a leptonically decaying W or Z boson. The analysis probes the production of new light bosons in a 15 <\ltmam_\mathrm{a}<\lt 60 GeV mass range. Assuming the standard model predictions for the Higgs boson production cross sections for pp \to WH and ZH, model independent upper limits at 95% confidence level are derived for the branching fraction B\mathcal{B}(H \to aa \to bbˉbbˉ\mathrm{b\bar{b}b\bar{b}}). The combined WH and ZH observed upper limit on the branching fraction ranges from 1.10 for ma=m_\mathrm{a} = 20 GeV to 0.36 for ma=m_\mathrm{a} = 60 GeV, complementing other measurements in the μμττ\mu\mu\tau\tau, ττττ\tau\tau\tau\tau and bb\ell\ell (=\ell= μ\mu,τ\tau) channels

    Search for new resonances decaying to pairs of merged diphotons in proton-proton collisions at s\sqrt{s} = 13 TeV

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    International audienceA search is presented for an extended Higgs sector with two new particles, X and ϕ\phi, in the process X \toϕϕ\phi\phi\to(γγ)(γγ)(\gamma\gamma)(\gamma\gamma). Novel neural networks classify events with diphotons that are merged and determine the diphoton masses. The search uses LHC proton-proton collision data at s\sqrt{s} = 13 TeV collected with the CMS detector, corresponding to an integrated luminosity of 138 fb1^{-1}. No evidence of such resonances is seen. Upper limits are set on the production cross section versus the resonance masses, representing the most sensitive search in this channel

    Search for baryon number violation in top quark production and decay using proton-proton collisions at s= \sqrt{s} = 13 TeV

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    A search is presented for baryon number violating interactions in top quark production and decay. The analysis uses data from proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the CMS detector at the LHC with an integrated luminosity of 138 fb1 ^{-1} . Candidate events are selected by requiring two oppositely-charged leptons (electrons or muons) and exactly one jet identified as originating from a bottom quark. Multivariate discriminants are used to separate the signal from the background. No significant deviation from the standard model prediction is observed. Upper limits are placed on the strength of baryon number violating couplings. For the first time the production of single top quarks via baryon number violating interactions is studied. This allows the search to set the most stringent constraints to date on the branching fraction of the top quark decay to a lepton, an up-type quark (u or c), and a down-type quark (d, s, or b). The results improve the previous bounds by three to six orders of magnitude based on the fermion flavor combination of the baryon number violating interactions.A search is presented for baryon number violating interactions in top quark production and decay. The analysis uses data from proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the CMS detector at the LHC with an integrated luminosity of 138 fb1^{-1}. Candidate events are selected by requiring two oppositely-charged leptons (electrons or muons) and exactly one jet identified as originating from a bottom quark. Multivariate discriminants are used to separate the signal from the background. No significant deviation from the standard model prediction is observed. Upper limits are placed on the strength of baryon number violating couplings. For the first time the production of single top quarks via baryon number violating interactions is studied. This allows the search to set the most stringent constraints to date on the branching fraction of the top quark decay to a lepton, an up-type quark (u or c), and a down-type quark (d, s, or b). The results improve the previous bounds by three to six orders of magnitude based on the fermion flavor combination of the baryon number violating interactions
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