14 research outputs found

    Rhythmicity of mood symptoms in individuals at risk for psychiatric disorders

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    Despite emerging evidence that disruption in circadian rhythms may contribute to the pathophysiology of psychiatric disorders, there is a significant knowledge gap on the rhythmicity of psychological symptoms. Here, we aimed at investigating the rhythmicity of mood symptoms in individuals at risk for psychiatric disorders. 391 Brazilian and 317 Spanish participants completed the Self-Reporting Questionnaire-20 for non-psychotic mental disorders; the Mood Rhythm Instrument was used to assess rhythmicity of mood symptoms and the Munich ChronoType Questionnaire to assess sleep patterns. We found that the rhythmicity of specific mood-related symptoms and behaviors, particularly pessimism and motivation to exercise, were associated with being at risk for psychiatric disorders, even after controlling for sleep timing, sleep deficit, and season of data collection. We also found that the peak of some mood symptoms and behaviors were different between individuals at high vs. low risk for psychiatric disorders, with specific differences between countries. These results are consistent with previous research showing that circadian misalignment is associated with higher risk for mental health conditions. These findings also suggest that lifestyle changes preventing circadian misalignment might be useful to reduce the risk of psychiatric disorders, where cultural differences must be taken into account

    Search for narrow resonances in the <math display="inline"><mi>b</mi></math>-tagged dijet mass spectrum in proton-proton collisions at <math display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>

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    International audienceA search is performed for narrow resonances decaying to final states of two jets, with at least one jet originating from a b quark, in proton-proton collisions at s=13  TeV. The data set corresponds to an integrated luminosity of 138  fb-1 collected with the CMS detector at the LHC. Jets originating from energetic b hadrons are identified through a b-tagging algorithm that utilizes a deep neural network or the presence of a muon inside a jet. The invariant mass spectrum of jet pairs is well described by a smooth parametrization and no evidence for the production of new particles is observed. Upper limits on the production cross section are set for excited b quarks and other resonances decaying to dijet final states containing b quarks. These limits exclude at 95% confidence level models of Z′ bosons with masses from 1.8 TeV to 2.4 TeV and of excited b quarks with masses from 1.8 TeV to 4.0 TeV. This is the most stringent exclusion of excited b quarks to date

    Measurement of inclusive and differential cross sections for single top quark production in association with a W boson in proton-proton collisions at s \sqrt{s} = 13 TeV

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    International audienceMeasurements of the inclusive and normalised differential cross sections are presented for the production of single top quarks in association with a W boson in proton-proton collisions at a centre-of-mass energy of 13 TeV. The data used were recorded with the CMS detector at the LHC during 2016–2018, and correspond to an integrated luminosity of 138 fb1^{−1}. Events containing one electron and one muon in the final state are analysed. For the inclusive measurement, a multivariate discriminant, exploiting the kinematic properties of the events is used to separate the signal from the dominant tt \textrm{t}\overline{\textrm{t}} background. A cross section of 79.2±0.9(stat)8.0+7.7(syst)±1.2(lumi) 79.2\pm 0.9{\left(\textrm{stat}\right)}_{-8.0}^{+7.7}\left(\textrm{syst}\right)\pm 1.2\left(\textrm{lumi}\right) pb is obtained, consistent with the predictions of the standard model. For the differential measurements, a fiducial region is defined according to the detector acceptance, and the requirement of exactly one jet coming from the fragmentation of a bottom quark. The resulting distributions are unfolded to particle level and agree with the predictions at next-to-leading order in perturbative quantum chromodynamics.[graphic not available: see fulltext

    Search for pair production of vector-like quarks in leptonic final states in proton-proton collisions at s \sqrt{s} = 13 TeV

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    A search is presented for vector-like T \mathrm{T} and B \mathrm{B} quark-antiquark pairs produced in proton-proton collisions at a center-of-mass energy of 13 TeV. Data were collected by the CMS experiment at the CERN LHC in 2016-2018, with an integrated luminosity of 138 fb1 ^{-1} . Events are separated into single-lepton, same-sign charge dilepton, and multilepton channels. In the analysis of the single-lepton channel a multilayer neural network and jet identification techniques are employed to select signal events, while the same-sign dilepton and multilepton channels rely on the high-energy signature of the signal to distinguish it from standard model backgrounds. The data are consistent with standard model background predictions, and the production of vector-like quark pairs is excluded at 95% confidence level for T \mathrm{T} quark masses up to 1.54 TeV and B \mathrm{B} quark masses up to 1.56 TeV, depending on the branching fractions assumed, with maximal sensitivity to decay modes that include multiple top quarks. The limits obtained in this search are the strongest limits to date for TT \mathrm{T} \overline{\mathrm{T}} production, excluding masses below 1.48 TeV for all decays to third generation quarks, and are the strongest limits to date for BB \mathrm{B} \overline{\mathrm{B}} production with B \mathrm{B} quark decays to tW.A search is presented for vector-like T and B quark-antiquark pairs produced in proton-proton collisions at a center-of-mass energy of 13 TeV. Data were collected by the CMS experiment at the CERN LHC in 2016–2018, with an integrated luminosity of 138 fb1^{−1}. Events are separated into single-lepton, same-sign charge dilepton, and multi-lepton channels. In the analysis of the single-lepton channel a multilayer neural network and jet identification techniques are employed to select signal events, while the same-sign dilepton and multilepton channels rely on the high-energy signature of the signal to distinguish it from standard model backgrounds. The data are consistent with standard model background predictions, and the production of vector-like quark pairs is excluded at 95% confidence level for T quark masses up to 1.54 TeV and B quark masses up to 1.56 TeV, depending on the branching fractions assumed, with maximal sensitivity to decay modes that include multiple top quarks. The limits obtained in this search are the strongest limits to date for TT \textrm{T}\overline{\textrm{T}} production, excluding masses below 1.48 TeV for all decays to third generation quarks, and are the strongest limits to date for BB \textrm{B}\overline{\textrm{B}} production with B quark decays to tW.[graphic not available: see fulltext]A search is presented for vector-like T and B quark-antiquark pairs produced in proton-proton collisions at a center-of-mass energy of 13 TeV. Data were collected by the CMS experiment at the CERN LHC in 2016-2018, with an integrated luminosity of 138 fb1^{-1}. Events are separated into single-lepton, same-sign charge dilepton, and multilepton channels. In the analysis of the single-lepton channel a multilayer neural network and jet identification techniques are employed to select signal events, while the same-sign dilepton and multilepton channels rely on the high-energy signature of the signal to distinguish it from standard model backgrounds. The data are consistent with standard model background predictions, and the production of vector-like quark pairs is excluded at 95% confidence level for T quark masses up to 1.54 TeV and B quark masses up to 1.56 TeV, depending on the branching fractions assumed, with maximal sensitivity to decay modes that include multiple top quarks. The limits obtained in this search are the strongest limits to date for TT\mathrm{T\overline{T}} production, excluding masses below 1.48 TeV for all decays to third generation quarks, and are the strongest limits to date for BB\mathrm{B\overline{B}} production with B quark decays to tW

    Measurement of the Higgs boson inclusive and differential fiducial production cross sections in the diphoton decay channel with pp collisions at s \sqrt{s} = 13 TeV

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    International audienceThe measurements of the inclusive and differential fiducial cross sections of the Higgs boson decaying to a pair of photons are presented. The analysis is performed using proton-proton collisions data recorded with the CMS detector at the LHC at a centre-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 137 fb1^{−1}. The inclusive fiducial cross section is measured to be σfid=73.45.3+5.4(stat)2.2+2.4(syst) {\sigma}_{\textrm{fid}}={73.4}_{-5.3}^{+5.4}{\left(\textrm{stat}\right)}_{-2.2}^{+2.4}\left(\textrm{syst}\right) fb, in agreement with the standard model expectation of 75.4 ± 4.1 fb. The measurements are also performed in fiducial regions targeting different production modes and as function of several observables describing the diphoton system, the number of additional jets present in the event, and other kinematic observables. Two double differential measurements are performed. No significant deviations from the standard model expectations are observed.[graphic not available: see fulltext

    Azimuthal Correlations within Exclusive Dijets with Large Momentum Transfer in Photon-Lead Collisions

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    International audienceThe structure of nucleons is multidimensional and depends on the transverse momenta, spatial geometry, and polarization of the constituent partons. Such a structure can be studied using high-energy photons produced in ultraperipheral heavy-ion collisions. The first measurement of the azimuthal angular correlations of exclusively produced events with two jets in photon-lead interactions at large momentum transfer is presented, a process that is considered to be sensitive to the underlying nuclear gluon polarization. This study uses a data sample of ultraperipheral lead-lead collisions at sNN=5.02  TeV, corresponding to an integrated luminosity of 0.38  nb-1, collected with the CMS experiment at the LHC. The measured second harmonic of the correlation between the sum and difference of the two jet transverse momentum vectors is found to be positive, and rising, as the dijet transverse momentum increases. A well-tuned model that has been successful at describing a wide range of proton scattering data from the HERA experiments fails to describe the observed correlations, suggesting the presence of gluon polarization effects

    Search for Higgs boson decays to a Z boson and a photon in proton-proton collisions at s \sqrt{s} = 13 TeV

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    International audienceResults are presented from a search for the Higgs boson decay H → Zγ, where Z → ℓ+^{+}^{−} with ℓ = e or μ. The search is performed using a sample of proton-proton (pp) collision data at a center-of-mass energy of 13 TeV, recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138 fb1^{−1}. Events are assigned to mutually exclusive categories, which exploit differences in both event topology and kinematics of distinct Higgs production mechanisms to enhance signal sensitivity. The signal strength μ, defined as the product of the cross section and the branching fraction \left[\sigma \left(\textrm{pp}\to \textrm{H}\right)\mathcal{B}\left(\textrm{H}\to \textrm{Z}\upgamma \right)\right] relative to the standard model prediction, is extracted from a simultaneous fit to the ℓ+^{+}^{−}γ invariant mass distributions in all categories and is measured to be μ = 2.4 ± 0.9 for a Higgs boson mass of 125.38 GeV. The statistical significance of the observed excess of events is 2.7 standard deviations. This measurement corresponds to \left[\sigma \left(\textrm{pp}\to \textrm{H}\right)\mathcal{B}\left(\textrm{H}\to \textrm{Z}\upgamma \right)\right]=0.21\pm 0.08 pb. The observed (expected) upper limit at 95% confidence level on μ is 4.1 (1.8), where the expected limit is calculated under the background-only hypothesis. The ratio of branching fractions \mathcal{B}\left(\textrm{H}\to \textrm{Z}\upgamma \right)/\mathcal{B}\left(\textrm{H}\to \upgamma \upgamma \right) is measured to be 1.50.6+0.7 {1.5}_{-0.6}^{+0.7} , which agrees with the standard model prediction of 0.69 ± 0.04 at the 1.5 standard deviation level.[graphic not available: see fulltext

    Search for heavy resonances and quantum black holes in eμ\mu, eτ\tau, and μτ\mu\tau final states in proton-proton collisions at s\sqrt{s} = 13 TeV

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    A search is reported for heavy resonances and quantum black holes decaying into eμ\mu, eτ\tau, and μτ\mu\tau final states in proton-proton collision data recorded by the CMS experiment at the CERN LHC during 2016-2018 at s=\sqrt{s} = 13 TeV, corresponding to an integrated luminosity of 138 fb1^{-1}. The eμ\mu, eτ\tau, and μτ\mu\tau invariant mass spectra are reconstructed, and no evidence is found for physics beyond the standard model. Upper limits are set at 95% confidence level on the product of the cross section and branching fraction for lepton flavor violating signals. Three benchmark signals are studied: resonant τ\tau sneutrino production in RR parity violating supersymmetric models, heavy Z' gauge bosons with lepton flavor violating decays, and nonresonant quantum black hole production in models with extra spatial dimensions. Resonant τ\tau sneutrinos are excluded for masses up to 4.2 TeV in the eμ\mu channel, 3.7 TeV in the eτ\tau channel, and 3.6 TeV in the μτ\mu\tau channel. A Z' boson with lepton flavor violating couplings is excluded up to a mass of 5.0 TeV in the eμ\mu channel, up to 4.3 TeV in the eτ\tau channel, and up to 4.1 TeV in the μτ\mu\tau channel. Quantum black holes in the benchmark model are excluded up to the threshold mass of 5.6 TeV in the eμ\mu channel, 5.2 TeV in the eτ\tau channel, and 5.0 TeV in the μτ\mu\tau channel. In addition, model-independent limits are extracted to allow comparisons with other models for the same final states and similar event selection requirements. The results of these searches provide the most stringent limits available from collider experiments for heavy particles that undergo lepton flavor violating decays.A search is reported for heavy resonances and quantum black holes decaying into eμ, eτ, and μτ final states in proton-proton collision data recorded by the CMS experiment at the CERN LHC during 2016–2018 at s \sqrt{s} = 13 TeV, corresponding to an integrated luminosity of 138 fb1^{−1}. The eμ, eτ, and μτ invariant mass spectra are reconstructed, and no evidence is found for physics beyond the standard model. Upper limits are set at 95% confidence level on the product of the cross section and branching fraction for lepton flavor violating signals. Three benchmark signals are studied: resonant τ sneutrino production in R parity violating supersymmetric models, heavy Z′ gauge bosons with lepton flavor violating decays, and nonresonant quantum black hole production in models with extra spatial dimensions. Resonant τ sneutrinos are excluded for masses up to 4.2TeV in the eμ channel, 3.7TeV in the eτ channel, and 3.6TeV in the μτ channel. A Z′ boson with lepton flavor violating couplings is excluded up to a mass of 5.0TeV in the eμ channel, up to 4.3Te V in the eτ channel, and up to 4.1TeV in the μτ channel. Quantum black holes in the benchmark model are excluded up to the threshold mass of 5.6TeV in the eμ channel, 5.2TeV in the eτ channel, and 5.0TeV in the μτ channel. In addition, model-independent limits are extracted to allow comparisons with other models for the same final states and similar event selection requirements. The results of these searches provide the most stringent limits available from collider experiments for heavy particles that undergo lepton flavor violating decays.[graphic not available: see fulltext]A search is reported for heavy resonances and quantum black holes decaying into eμ\mu, eτ\tau, and μτ\mu\tau final states in proton-proton collision data recorded by the CMS experiment at the CERN LHC during 2016-2018 at s\sqrt{s} = 13 TeV, corresponding to an integrated luminosity of 138 fb1^{-1}. The eμ\mu, eτ\tau, and μτ\mu\tau invariant mass spectra are reconstructed, and no evidence is found for physics beyond the standard model. Upper limits are set at 95% confidence level on the product of the cross section and branching fraction for lepton flavor violating signals. Three benchmark signals are studied: resonant τ\tau sneutrino production in RR parity violating supersymmetric models, heavy Z' gauge bosons with lepton flavor violating decays, and nonresonant quantum black hole production in models with extra spatial dimensions. Resonant τ\tau sneutrinos are excluded for masses up to 4.2 TeV in the eμ\mu channel, 3.7 TeV in the eτ\tau channel, and 3.6 TeV in the μτ\mu\tau channel. A Z' boson with lepton flavor violating couplings is excluded up to a mass of 5.0 TeV in the eμ\mu channel, up to 4.3 TeV in the eτ\tau channel, and up to 4.1 TeV in the μτ\mu\tau channel. Quantum black holes in the benchmark model are excluded up to the threshold mass of 5.6 TeV in the eμ\mu channel, 5.2 TeV in the eτ\tau channel, and 5.0 TeV in the μτ\mu\tau channel. In addition, model-independent limits are extracted to allow comparisons with other models for the same final states and similar event selection requirements. The results of these searches provide the most stringent limits available from collider experiments for heavy particles that undergo lepton flavor violating decays

    Search for nonresonant Higgs boson pair production in the four leptons plus two b jets final state in proton-proton collisions at s=\sqrt{s} = 13 TeV

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    The first search for nonresonant production of Higgs boson pairs (HH) with one H decaying into four leptons and the other into a pair of b quarks is presented, using proton-proton collisions recorded at a center-of-mass energy of s=\sqrt{s} = 13 TeV by the CMS experiment. The analyzed data correspond to an integrated luminosity of 138 fb1^{-1}. A 95% confidence level upper limit of 32.4 is set on the signal strength modifier μ\mu, defined as the ratio of the observed HH production rate in the HHZZbbˉ4bbˉ{\mathrm{H}\mathrm{H}} \to\mathrm{Z}\mathrm{Z}^{*}\mathrm{b}\mathrm{\bar{b}}\to 4\ell\mathrm{b}\mathrm{\bar{b}} decay channel to the standard model expectation. Possible modifications of the H trilinear coupling λHHH\lambda_\text{HHH} with respect to the standard model (SM) value are investigated. The coupling modifier κλ\kappa_{\lambda}, defined as λHHH\lambda_\text{HHH} divided by its SM prediction, is constrained to be within the observed (expected) range -8.8 (-9.8) <κλ< < \kappa_{\lambda} < 13.4 (15.0) at 95% confidence level.The first search for nonresonant production of Higgs boson pairs (HH) with one H decaying into four leptons and the other into a pair of b quarks is presented, using proton-proton collisions recorded at a center-of-mass energy of s \sqrt{s} = 13 TeV by the CMS experiment. The analyzed data correspond to an integrated luminosity of 138 fb1^{−1}. A 95% confidence level upper limit of 32.4 is set on the signal strength modifier μ, defined as the ratio of the observed HH production rate in the HHZZbb4bb \textrm{HH}\to {\textrm{ZZ}}^{\ast}\textrm{b}\overline{\textrm{b}}\to 4\ell \textrm{b}\overline{\textrm{b}} decay channel to the standard model (SM) expectation. Possible modifications of the H trilinear coupling λHHH_{HHH} with respect to the SM value are investigated. The coupling modifier κλ_{λ}, defined as λHHH_{HHH} divided by its SM prediction, is constrained to be within the observed (expected) range −8.8 (−9.8) < κλ_{λ}< 13.4 (15.0) at 95% confidence level.[graphic not available: see fulltext]The first search for nonresonant production of Higgs boson pairs (HH) with one H decaying into four leptons and the other into a pair of b quarks is presented, using proton-proton collisions recorded at a center-of-mass energy of s\sqrt{s} = 13 TeV by the CMS experiment. The analyzed data correspond to an integrated luminosity of 138 fb1^{-1}. A 95% confidence level upper limit of 32.4 is set on the signal strength modifier μ\mu, defined as the ratio of the observed HH production rate in the HH \to ZZ*bbˉ\mathrm{\bar{b}} \to 4\ellbbˉ\mathrm{\bar{b}} decay channel to the standard model expectation. Possible modifications of the H trilinear coupling λHHH\lambda_\text{HHH} with respect to the standard model (SM) value are investigated. The coupling modifier κλ\kappa_{\lambda}, defined as λHHH\lambda_\text{HHH} divided by its SM prediction, is constrained to be within the observed (expected) range -8.8 (-9.8) << κλ\kappa_{\lambda} << 13.4 (15.0) at 95% confidence level

    Measurement of the top quark pole mass using tt \textrm{t}\overline{\textrm{t}} +jet events in the dilepton final state in proton-proton collisions at s \sqrt{s} = 13 TeV

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    A measurement of the top quark pole mass mtpole{{m_{\mathrm{t}}} ^{\text{pole}}} in events where a top quark-antiquark pair (ttˉ\mathrm{t\bar{t}}) is produced in association with at least one additional jet (ttˉ\mathrm{t\bar{t}}+jet) is presented. This analysis is performed using proton-proton collision data at s=\sqrt{s} = 13 TeV collected by the CMS experiment at the CERN LHC, corresponding to a total integrated luminosity of 36.3 fb1^{-1}. Events with two opposite-sign leptons in the final state (e+^{+}e^{-}, μ+μ\mu^{+}\mu^{-}, e±μ^{\pm}\mu^{\mp}) are analyzed. The reconstruction of the main observable and the event classification are optimized using multivariate analysis techniques based on machine learning. The production cross section is measured as a function of the inverse of the invariant mass of the ttˉ\mathrm{t\bar{t}}+jet system at the parton level using a maximum likelihood unfolding. Given a reference parton distribution function (PDF), the top quark pole mass is extracted using the theoretical predictions at next-to-leading order. For the ABMP16NLO PDF, this results in mtpole={{m_{\mathrm{t}}} ^{\text{pole}}} = 172.94 ±\pm 1.37 GeV.A measurement of the top quark pole mass mtpole {m}_{\textrm{t}}^{\textrm{pole}} in events where a top quark-antiquark pair (tt \textrm{t}\overline{\textrm{t}} ) is produced in association with at least one additional jet (tt \textrm{t}\overline{\textrm{t}} +jet) is presented. This analysis is performed using proton-proton collision data at s \sqrt{s} = 13 TeV collected by the CMS experiment at the CERN LHC, corresponding to a total integrated luminosity of 36.3 fb1^{−1}. Events with two opposite-sign leptons in the final state (e+^{+}e^{−}, μ+^{+}μ^{−}, e±^{±}μ^{∓}) are analyzed. The reconstruction of the main observable and the event classification are optimized using multivariate analysis techniques based on machine learning. The production cross section is measured as a function of the inverse of the invariant mass of the tt \textrm{t}\overline{\textrm{t}} +jet system at the parton level using a maximum likelihood unfolding. Given a reference parton distribution function (PDF), the top quark pole mass is extracted using the theoretical predictions at next-to-leading order. For the ABMP16NLO PDF, this results in mtpole {m}_{\textrm{t}}^{\textrm{pole}} = 172.93 ± 1.36 GeV.[graphic not available: see fulltext]A measurement of the top quark pole mass mtpolem_\mathrm{t}^\text{pole} in events where a top quark-antiquark pair (ttˉ\mathrm{t\bar{t}}) is produced in association with at least one additional jet (ttˉ\mathrm{t\bar{t}}+jet) is presented. This analysis is performed using proton-proton collision data at s\sqrt{s} = 13 TeV collected by the CMS experiment at the CERN LHC, corresponding to a total integrated luminosity of 36.3 fb1^{-1}. Events with two opposite-sign leptons in the final state (e+^+e^-, μ+μ\mu^+\mu^-, e±μ^\pm\mu^\mp) are analyzed. The reconstruction of the main observable and the event classification are optimized using multivariate analysis techniques based on machine learning. The production cross section is measured as a function of the inverse of the invariant mass of the ttˉ\mathrm{t\bar{t}}+jet system at the parton level using a maximum likelihood unfolding. Given a reference parton distribution function (PDF), the top quark pole mass is extracted using the theoretical predictions at next-to-leading order. For the ABMP16NLO PDF, this results in mtpolem_\mathrm{t}^\text{pole} = 172.93 ±\pm 1.36 GeV
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