Showing papers by "Luisa Benussi published in 2019"
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TL;DR: Combined measurements of the production and decay rates of the Higgs boson, as well as its couplings to vector bosons and fermions, are presented and constraints are placed on various two Higgs doublet models.
Abstract: Combined measurements of the production and decay rates of the Higgs boson, as well as its couplings to vector bosons and fermions, are presented. The analysis uses the LHC proton–proton collision data set recorded with the CMS detector in 2016 at $\sqrt{s}=13\,\text {Te}\text {V} $ , corresponding to an integrated luminosity of 35.9 ${\,\text {fb}^{-1}} $ . The combination is based on analyses targeting the five main Higgs boson production mechanisms (gluon fusion, vector boson fusion, and associated production with a $\mathrm {W}$ or $\mathrm {Z}$ boson, or a top quark-antiquark pair) and the following decay modes: $\mathrm {H} \rightarrow \gamma \gamma $ , $\mathrm {Z}\mathrm {Z}$ , $\mathrm {W}\mathrm {W}$ , $\mathrm {\tau }\mathrm {\tau }$ , $\mathrm {b} \mathrm {b} $ , and $\mathrm {\mu }\mathrm {\mu }$ . Searches for invisible Higgs boson decays are also considered. The best-fit ratio of the signal yield to the standard model expectation is measured to be $\mu =1.17\pm 0.10$ , assuming a Higgs boson mass of $125.09\,\text {Ge}\text {V} $ . Additional results are given for various assumptions on the scaling behavior of the production and decay modes, including generic parametrizations based on ratios of cross sections and branching fractions or couplings. The results are compatible with the standard model predictions in all parametrizations considered. In addition, constraints are placed on various two Higgs doublet models.
451 citations
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438 citations
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TL;DR: In this article, a search for invisible decays of a Higgs boson via vector boson fusion is performed using proton-proton collision data collected with the CMS detector at the LHC in 2016 at a center-of-mass energy root s = 13 TeV, corresponding to an integrated luminosity of 35.9fb(-1).
347 citations
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TL;DR: A search for Higgs boson pair production using the combined results from four final states: bbγγ, bbττ, bbbb, and bbVV, where V represents a W or Z boson, is performed using data collected in 2016 by the CMS experiment from LHC proton-proton collisions.
Abstract: This Letter describes a search for Higgs boson pair production using the combined results from four final states: bbγγ, bbττ, bbbb, and bbVV, where V represents a W or Z boson. The search is performed using data collected in 2016 by the CMS experiment from LHC proton-proton collisions at s=13 TeV, corresponding to an integrated luminosity of 35.9 fb-1. Limits are set on the Higgs boson pair production cross section. A 95% confidence level observed (expected) upper limit on the nonresonant production cross section is set at 22.2 (12.8) times the standard model value. A search for narrow resonances decaying to Higgs boson pairs is also performed in the mass range 250–3000 GeV. No evidence for a signal is observed, and upper limits are set on the resonance production cross section.
169 citations
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TL;DR: In this paper, on-shell and off-shell Higgs boson production in the four-lepton final state are presented, using data from the CMS experiment at the LHC that correspond to an integrated luminosity of 80.2 fb(-1) at a center-of-mass energy of 13 TeV.
Abstract: Studies of on-shell and off-shell Higgs boson production in the four-lepton final state are presented, using data from the CMS experiment at the LHC that correspond to an integrated luminosity of 80.2 fb(-1) at a center-of-mass energy of 13 TeV. Joint constraints are set on the Higgs boson total width and parameters that express its anomalous couplings to two electroweak vector bosons. These results are combined with those obtained from the data collected at center-of-mass energies of 7 and 8 TeV, corresponding to integrated luminosities of 5.1 and 19.7 fb(-1), respectively. Kinematic information from the decay particles and the associated jets are combined using matrix element techniques to identify the production mechanism and to increase sensitivity to the Higgs boson couplings in both production and decay. The constraints on anomalous HVV couplings are found to be consistent with the standard model expectation in both the on-shell and off-shell regions. Under the assumption of a coupling structure similar to that in the standard model, the Higgs boson width is constrained to be 3.2(-2.2)(+2.8)MeV while the expected constraint based on simulation is 4.1(-4.0)(+5.0) MeV. The constraints on the width remain similar with the inclusion of the tested anomalous HVV interactions.
135 citations
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TL;DR: The first observation of the Higgs boson decay to W boson pairs by the LHC experiment was reported in this article, where the cross section times branching fraction was 1.28−0.17+0.18 times the standard model prediction.
86 citations
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TL;DR: In this article, a search for charged Higgs bosons in the H$−−1−ε decay mode in the hadronic final state and in final states with an electron or a muon is presented.
Abstract: A search is presented for charged Higgs bosons in the H$^{±}$ → τ$^{±}$ν$_{τ}$ decay mode in the hadronic final state and in final states with an electron or a muon. The search is based on proton-proton collision data recorded by the CMS experiment in 2016 at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb$^{−1}$. The results agree with the background expectation from the standard model. Upper limits at 95% confidence level are set on the production cross section times branching fraction to τ$^{±}$ν$_{τ}$ for an H$^{±}$ in the mass range of 80GeV to 3TeV, including the region near the top quark mass. The observed limit ranges from 6 pb at 80 GeV to 5 fb at 3 TeV. The limits are interpreted in the context of the minimal supersymmetric standard model m$_{h}^{hod −}$ scenario.
71 citations
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TL;DR: In this article, the authors measured the differential cross sections of Z bosons produced in proton-proton collisions at 13 TeV and decaying to muons and electrons, and compared the results to theoretical predictions using fixed order, resummed, and parton shower calculations.
Abstract: Measurements are presented of the differential cross sections for Z bosons produced in proton-proton collisions at $$ \sqrt{s} $$
= 13 TeV and decaying to muons and electrons. The data analyzed were collected in 2016 with the CMS detector at the LHC and correspond to an integrated luminosity of 35.9 fb−1. The measured fiducial inclusive product of cross section and branching fraction agrees with next-to-next-to-leading order quantum chromodynamics calculations. Differential cross sections of the transverse momentum pT, the optimized angular variable $$ {\phi}_{\eta}^{\ast } $$
, and the rapidity of lepton pairs are measured. The data are corrected for detector effects and compared to theoretical predictions using fixed order, resummed, and parton shower calculations. The uncertainties of the measured normalized cross sections are smaller than 0.5% for $$ {\phi}_{\eta}^{\ast } $$
< 0.5 and for $$ {p}_{\mathrm{T}}^{\mathrm{Z}} $$
< 50 GeV.
70 citations
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TL;DR: In this paper, a measurement of the top quark-antiquark pair production cross section in proton-proton collisions at a centre-of-mass energy of 13
Abstract: A measurement of the top quark–antiquark pair production cross section $\sigma _{\mathrm {t}\overline{\mathrm {t}}} $ in proton–proton collisions at a centre-of-mass energy of 13 $\,\text {Te}\text {V}$ is presented. The data correspond to an integrated luminosity of $35.9{\,\text {fb}^{-1}} $ , recorded by the CMS experiment at the CERN LHC in 2016. Dilepton events ( $\mathrm {e}^{\pm }$ $\mathrm {\mu }^{{\mp }}$ , $\mathrm {\mu ^+}\mathrm {\mu ^-}$ , $\mathrm {e}^+\mathrm {e}^-$ ) are selected and the cross section is measured from a likelihood fit. For a top quark mass parameter in the simulation of $ m_\mathrm {\mathrm {t}} ^{\mathrm {MC}} = 172.5 \,\text {Ge}\text {V} $ the fit yields a measured cross section $\sigma _{\mathrm {t}\overline{\mathrm {t}}} = 803 \pm 2 \,\text {(stat)} \pm 25 \,\text {(syst)} \pm 20 \,\text {(lumi)} \,\text {pb} $ , in agreement with the expectation from the standard model calculation at next-to-next-to-leading order. A simultaneous fit of the cross section and the top quark mass parameter in the powheg simulation is performed. The measured value of $m_\mathrm {\mathrm {t}} ^{\mathrm {MC}} = 172.33 \pm 0.14 \,\text {(stat)} \,^{+0.66-0.72} \,\text {(syst)} \,\text {Ge}\text {V} $ is in good agreement with previous measurements. The resulting cross section is used, together with the theoretical prediction, to determine the top quark mass and to extract a value of the strong coupling constant with different sets of parton distribution functions.
61 citations
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TL;DR: In this article, measurements of differential top quark pair cross sections using events produced in proton-proton collisions at a centre-of-mass energy of 13 TeV containing two oppositely charged leptons are presented.
Abstract: Measurements of differential top quark pair $ \mathrm{t}\overline{\mathrm{t}} $ cross sections using events produced in proton-proton collisions at a centre-of-mass energy of 13 TeV containing two oppositely charged leptons are presented. The data were recorded by the CMS experiment at the CERN LHC in 2016 and correspond to an integrated luminosity of 35.9 fb$^{−1}$. The differential cross sections are presented as functions of kinematic observables of the top quarks and their decay products, the $ \mathrm{t}\overline{\mathrm{t}} $ system, and the total number of jets in the event. The differential cross sections are defined both with particle-level objects in a fiducial phase space close to that of the detector acceptance and with parton-level top quarks in the full phase space. All results are compared with standard model predictions from Monte Carlo simulations with next-to-leading-order (NLO) accuracy in quantum chromodynamics (QCD) at matrix-element level interfaced to parton-shower simulations. Where possible, parton-level results are compared to calculations with beyond-NLO precision in QCD. Significant disagreement is observed between data and all predictions for several observables. The measurements are used to constrain the top quark chromomagnetic dipole moment in an effective field theory framework at NLO in QCD and to extract $ \mathrm{t}\overline{\mathrm{t}} $ and leptonic charge asymmetries.
59 citations
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TL;DR: Lower limits at 95% confidence level are placed on the masses of the T and B quarks for a range of branching fractions, consistent with standard model background estimations.
Abstract: A search for the pair production of heavy vector-like partners T and B of the top and bottom quarks has been performed by the CMS experiment at the CERN LHC using proton-proton collisions at . The data sample was collected in 2016 and corresponds to an integrated luminosity of 35.9 production include those where one of the T quarks decays via TtZ and the other via TbW, tZ, or tH, where H is a Higgs boson. For the BB case, final states include those where one of the B quarks decays via BbZ and the other BtW, bZ, or bH. Events with two oppositely charged electrons or muons, consistent with coming from the decay of a Z boson, and jets are investigated. The number of observed events is consistent with standard model background estimations. Lower limits at 95% confidence level are placed on the masses of the T and B quarks for a range of branching fractions. Assuming 100% branching fractions for TtZ, and BbZ, T and B quark mass values below 1280 and 1130 respectively, are excluded.
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TL;DR: In this article, a search for new massive particles decaying into a pair of Higgs bosons in proton-proton collisions at a center-of-mass energy of 13 TeV is presented.
Abstract: A search for new massive particles decaying into a pair of Higgs bosons in proton-proton collisions at a center-of-mass energy of 13 TeV is presented. Data were collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 35.9 fb−1. The search is performed for resonances with a mass between 0.8 and 3.5 TeV using events in which one Higgs boson decays into a bottom quark pair and the other decays into two W bosons that subsequently decay into a lepton, a neutrino, and a quark pair. The Higgs boson decays are reconstructed with techniques that identify final state quarks as substructure within boosted jets. The data are consistent with standard model expectations. Exclusion limits are placed on the product of the cross section and branching fraction for generic spin-0 and spin-2 massive resonances. The results are interpreted in the context of radion and bulk graviton production in models with a warped extra spatial dimension. These are the best results to date from searches for an HH resonance decaying to this final state, and they are comparable to the results from searches in other channels for resonances with masses below 1.5 TeV.
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TL;DR: A search for a heavy pseudoscalar boson decaying to a Z boson and a Higgs boson with mass of 125 that decays either into a pair of electrons, muons, or neutrinos is presented.
Abstract: A search is presented for a heavy pseudoscalar boson $\text {A}$ decaying to a Z boson and a Higgs boson with mass of 125 $\,\text {GeV}$ . In the final state considered, the Higgs boson decays to a bottom quark and antiquark, and the Z boson decays either into a pair of electrons, muons, or neutrinos. The analysis is performed using a data sample corresponding to an integrated luminosity of 35.9 $\,\text {fb}^{-1}$ collected in 2016 by the CMS experiment at the LHC from proton–proton collisions at a center-of-mass energy of 13 $\,\text {Te}\text {V}$ . The data are found to be consistent with the background expectations. Exclusion limits are set in the context of two-Higgs-doublet models in the $\text {A}$ boson mass range between 225 and 1000 $\,\text {GeV}$ .
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TL;DR: In this article, a search for long-lived particles decaying into jets was conducted at the LHC from proton-proton collisions at a center-of-mass energy of 13 TeV in 2016, corresponding to an integrated luminosity of 35.9 fb-1.
Abstract: A search for long-lived particles decaying into jets is presented. Data were collected with the CMS detector at the LHC from proton-proton collisions at a center-of-mass energy of 13 TeV in 2016, corresponding to an integrated luminosity of 35.9 fb-1. The search examines the distinctive topology of displaced tracks and secondary vertices. The selected events are found to be consistent with standard model predictions. For a simplified model in which long-lived neutral particles are pair produced and decay to two jets, pair production cross sections larger than 0.2 fb are excluded at 95% confidence level for a long-lived particle mass larger than 1000 GeV and proper decay lengths between 3 and 130 mm. Several supersymmetry models with gauge-mediated supersymmetry breaking or R-parity violation, where pair-produced long-lived gluinos or top squarks decay to several final-state topologies containing displaced jets, are also tested. For these models, in the mass ranges above 200 GeV, gluino masses up to 2300–2400 GeV and top squark masses up to 1350–1600 GeV are excluded for proper decay lengths approximately between 10 and 100 mm. These are the most restrictive limits to date on these models.
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TL;DR: To identify novel CSF biomarkers in GRN‐associated frontotemporal dementia (FTD) by proteomics using mass spectrometry (MS) using peptide-based methods.
Abstract: Objective: To identify novel CSF biomarkers in GRN-associated frontotemporal dementia (FTD) by proteomics using mass spectrometry (MS). Methods:
Unbiased MS was applied to CSF samples from 19 presymptomatic and 9
symptomatic GRN mutation carriers and 24 noncarriers. Protein abundances
were compared between these groups. Proteins were then selected for validation
if identified by ≥4 peptides and if fold change was ≤0.5 or ≥2.0. Validation and
absolute quantification by parallel reaction monitoring (PRM), a high-resolution targeted MS method, was performed on an international cohort (n = 210)
of presymptomatic and symptomatic GRN, C9orf72 and MAPT mutation carriers. Results: Unbiased MS revealed 20 differentially abundant proteins between
symptomatic mutation carriers and noncarriers and nine between symptomatic
and presymptomatic carriers. Seven of these proteins fulfilled our criteria for
validation. PRM analyses revealed that symptomatic GRN mutation carriers had
significantly lower levels of neuronal pentraxin receptor (NPTXR), receptortype tyrosine-protein phosphatase N2 (PTPRN2), neurosecretory protein VGF,
chromogranin-A (CHGA), and V-set and transmembrane domain-containing
protein 2B (VSTM2B) than presymptomatic carriers and noncarriers. Symptomatic C9orf72 mutation carriers had lower levels of NPTXR, PTPRN2,
CHGA, and VSTM2B than noncarriers, while symptomatic MAPT mutation
carriers had lower levels of NPTXR and CHGA than noncarriers. Interpretation: We identified and validated five novel CSF biomarkers in GRN-associated
FTD. Our results show that synaptic, secretory vesicle, and inflammatory proteins are dysregulated in the symptomatic stage and may provide new insights into the pathophysiology of genetic FTD. Further validation is needed to investigate their clinical applicability as diagnostic or monitoring biomarkers.
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01 Jan 2019
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TL;DR: In this paper, a set of parton-level normalized differential cross sections, sensitive to each of the independent coefficients of the spin-dependent parts of the t (t) over bar production density matrix, is measured for the first time at 13 TeV.
Abstract: Measurements of the top quark polarization and top quark pair (t (t) over bar) spin correlations are presented using events containing two oppositely charged leptons (e(+)e(-), e(+/-)mu(-/+), or mu(+)mu(-)) produced in proton-proton collisions at a center-of-mass energy of 13 TeV. The data were recorded by the CMS experiment at the LHC in 2016 and correspond to an integrated luminosity of 35.9 fb(-1) . A set of parton-level normalized differential cross sections, sensitive to each of the independent coefficients of the spin-dependent parts of the t (t) over bar production density matrix, is measured for the first time at 13 TeV. The measured distributions and extracted coefficients are compared with standard model predictions from simulations at next-to-leading-order (NLO) accuracy in quantum chromodynamics (QCD), and from NLO QCD calculations including electroweak corrections. All measurements are found to be consistent with the expectations of the standard model. The normalized differential cross sections are used in fits to constrain the anomalous chromomagnetic and chromoelectric dipole moments of the top quark to -0.24 < C-tG/Lambda(2) < 0.07 TeV-2 and -0.33 < C-tG(I)/Lambda(2) < 0.20 TeV-2, respectively, at the 95% confidence level.
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TL;DR: In this paper, a search for long-lived particles decaying to displaced, non-prompt jets and missing transverse momentum is presented, and the results of the search are consistent with the background prediction and are interpreted using a gauge-mediated supersymmetry breaking reference model with a gluino next-to-lightest supersymmetric particle.
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TL;DR: In this article, measurements of associated production of a W boson and a charm quark in proton-proton collisions at a center-of-mass energy of 13 $\,\text {Te}\text {V}$ correspond to an integrated luminosity of 35.7
Abstract: Measurements are presented of associated production of a $\mathrm {W}$ boson and a charm quark ( $\mathrm {W}+\mathrm {c}$ ) in proton–proton collisions at a center-of-mass energy of 13 $\,\text {Te}\text {V}$ . The data correspond to an integrated luminosity of 35.7 $\,\text {fb}^{-1}$ collected by the CMS experiment at the CERN LHC. The $\mathrm {W}$ bosons are identified by their decay into a muon and a neutrino. The charm quarks are tagged via the full reconstruction of ${\mathrm {D}^{*}(2010)^{\pm }}$ mesons that decay via ${\mathrm {D}^{*}(2010)^{\pm }}\rightarrow \mathrm {D}^0 + {\pi ^{\pm }}\rightarrow \mathrm {K}^{\mp } + {\pi ^{\pm }}+ {\pi ^{\pm }}$ . A cross section is measured in the fiducial region defined by the muon transverse momentum $p_{\mathrm {T}} ^{\mu } > 26\,\text {Ge}\text {V} $ , muon pseudorapidity $|\eta ^{\mu } | 5\,\text {Ge}\text {V} $ . The inclusive cross section for this kinematic range is $\sigma (\mathrm {W}+\mathrm {c})=1026\pm 31\,\text {(stat)} \begin{array}{c} +76\\ -72 \end{array}\,\text {(syst)} \text { pb} $ . The cross section is also measured differentially as a function of the pseudorapidity of the muon from the $\mathrm {W}$ boson decay. These measurements are compared with theoretical predictions and are used to probe the strange quark content of the proton.
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TL;DR: It is observed that biological changes and intracortical facilitation transmission abnormalities significantly antecede the emergence of clinical symptoms of at least 3 decades and this highlights how several biomarkers can show different aspects and rates of decline, possibly correlated with the underlying physiopathological process, that arise decades before the onset of clinical Symptoms.
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University of Cambridge1, Erasmus University Rotterdam2, University of Brescia3, University of Milan4, University of Toronto5, Sunnybrook Research Institute6, Sunnybrook Health Sciences Centre7, Karolinska Institutet8, Karolinska University Hospital9, University of Geneva10, Laval University11, University of Western Ontario12, University of Lisbon13, University of Florence14, UCL Institute of Neurology15, University of Coimbra16, University of Ulm17, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico18, University of Tübingen19, Katholieke Universiteit Leuven20, University of Manchester21, McGill University22, Ludwig Maximilian University of Munich23, Toronto Rehabilitation Institute24, University of London25, University of Amsterdam26, Mayo Clinic27, University Health Network28, University of Oxford29
TL;DR: It is proposed that maintaining the efficient organization of the brain's functional network supports cognitive health even as atrophy and connectivity decline presymptomatically.
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TL;DR: In this paper, the authors measured the performance of the Higgs boson in the diphoton decay channel using the data set of proton-proton collisions at 13 TeV collected by the CMS experiment at the LHC in 2016.
Abstract: Measurements of the inclusive and differential production cross sections for the Higgs boson in the diphoton decay channel are performed using the data set of proton-proton collisions at 13 TeV collected by the CMS experiment at the LHC in 2016 and corresponding to an integrated luminosity of 35.9 fb(-1). The cross sections are measured in a fiducial phase space defined by a set of requirements on the isolation and kinematic variables of the photons. Differential cross sections are measured as functions of the kinematic properties of the diphoton system and the event. A subset of the measurements is performed in regions of the fiducial phase space, where relative contributions of specific Higgs boson production mechanisms are enhanced. The total cross section in the chosen fiducial phase space is measured to be 84 +/- 11 (stat) +/- 7 (syst) fb = 84 +/- 13 fb, to be compared with a theoretical prediction of 73 +/- 4 fb. All measurements are found to be in agreement with the theoretical predictions for the standard model Higgs boson with a mass of 125.09 GeV within the experimental and theoretical uncertainties.
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TL;DR: In this paper, a statistical combination of searches for heavy resonances decaying to pairs of bosons or leptons is presented, which correspond to an integrated luminosity of 35.9 fb −1 collected during 2016 by the CMS experiment at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV.
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TL;DR: In this paper, a search for the single production of vector-like quarks in proton-proton collisions at TeV was presented, and exclusion limits at 95% confidence level were set on the product of the production cross section and branching fraction as a function of the vectorlike quark mass.
Abstract: A search is presented for the single production of vector-like quarks in proton-proton collisions at TeV. The data, corresponding to an integrated luminosity of 35.9fb-1, were recorded with the CMS experiment at the LHC. The analysis focuses on the vector-like quark decay into a top quark and a W boson, with one muon or electron in the final state. The mass of the vector-like quark candidate is reconstructed from hadronic jets, the lepton, and the missing transverse momentum. Methods for the identification of b quarks and of highly Lorentz boosted hadronically decaying top quarks and W bosons are exploited in this search. No significant deviation from the standard model background expectation is observed. Exclusion limits at 95% confidence level are set on the product of the production cross section and branching fraction as a function of the vector-like quark mass, which range from 0.3 to 0.03pb for vector-like quark masses of 700 to 2000GeV. Mass exclusion limits up to 1660GeV are obtained, depending on the vector-like quark type, coupling, and decay width. These represent the most stringent exclusion limits for the single production of vector-like quarks in this channel.
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TL;DR: In this paper, a search for three additional operators that would lead to anomalous WWγ or WWZ couplings with respect to those in the standard model is presented, constrained by studying events with two vector bosons, a W boson decaying to eν or μν, and a W or Z boson reconstructed as a single, massive, large-radius jet.
Abstract: A search is presented for three additional operators that would lead to anomalous WWγ or WWZ couplings with respect to those in the standard model. They are constrained by studying events with two vector bosons, a W boson decaying to eν or μν, and a W or Z boson decaying hadronically, reconstructed as a single, massive, large- radius jet. The search uses a data set of proton-proton collisions at a centre-of-mass energy of 13 TeV, recorded by the CMS experiment at the CERN LHC in 2016, and corresponding to an integrated luminosity of 35.9 fb$^{−1}$. Using the reconstructed diboson invariant mass, 95% confidence intervals are obtained for the anomalous coupling parameters of −1.58 < $c_{WWW}$/Λ$^{2}$< 1.59 TeV$^{−2}$, −2.00 < c$_{W}$/Λ$^{2}$< 2.65 TeV$^{−2}$, and −8.78 < c$_{B}$/Λ$^{2}$< 8.54 TeV$^{−2}$, in agreement with standard model expectations of zero for each parameter. These are the strictest bounds on these parameters to date.
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TL;DR: In this paper, a top quark mass measurement was performed using 35.9fb-1 of LHC proton-proton collision data collected with the CMS detector at s=13TeV.
Abstract: A top quark mass measurement is performed using 35.9fb-1 of LHC proton-proton collision data collected with the CMS detector at s=13TeV . The measurement uses the tt¯ all-jets final state. A kinematic fit is performed to reconstruct the decay of the tt¯ system and suppress the multijet background. Using the ideogram method, the top quark mass ( mt ) is determined, simultaneously constraining an additional jet energy scale factor ( JSF ). The resulting value of mt=172.34±0.20(stat+JSF)±0.70(syst)GeV is in good agreement with previous measurements. In addition, a combined measurement that uses the tt¯ lepton+jets and all-jets final states is presented, using the same mass extraction method, and provides an mt measurement of 172.26±0.07(stat+JSF)±0.61(syst)GeV . This is the first combined mt extraction from the lepton+jets and all-jets channels through a single likelihood function.
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TL;DR: In this paper, a search is presented for massive narrow resonances decaying either into two Higgs bosons, or into a higgs boson and a W or Z boson.
Abstract: A search is presented for massive narrow resonances decaying either into two Higgs bosons, or into a Higgs boson and a W or Z boson. The decay channels considered are HHbb+- and VHqq-, where H denotes the Higgs boson, and V denotes the W or Z boson. This analysis is based on a data sample of proton-proton collisions collected at a center-of-mass energy of 13 TeV by the CMS Collaboration, corresponding to an integrated luminosity of 35.9 fb(-1). For the TeV-scale mass resonances considered, substructure techniques provide ways to differentiate among the hadronization products from vector boson decays to quarks, Higgs boson decays to bottom quarks, and quark- or gluon-induced jets. Reconstruction techniques are used that have been specifically optimized to select events in which the tau lepton pair is highly boosted. The observed data are consistent with standard model expectations and upper limits are set at 95% confidence level on the product of cross section and branching fraction for resonance masses between 0.9 and 4.0 TeV. Exclusion limits are set in the context of bulk radion and graviton models:spin-0 radion resonances are excluded below a mass of 2.7 TeV at 95% confidence level. In the spin-1 heavy vector triplet framework, mass-degenerate W and Z resonances with dominant couplings to the standard model gauge bosons are excluded below a mass of 2.8 TeV at 95% confidence level. These are the first limits for massive resonances at the TeV scale with these decay channels at 13 TeV.
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TL;DR: FTLD is a more common form of dementia than previously recognized, with a risk spanning in a wide age range and with maximum incidence in the mid-70s, according to the Italian general population in 2017.
Abstract: Objective The goal of the present work, based on a collaborative research registry in Italy (the Salento-Brescia Registry), was to assess the incidence of frontotemporal lobar degeneration (FTLD) and to define the frequencies of different FTLD phenotypes in the general population. Methods The study was conducted from January 1, 2017, to December 31, 2017, in 2 Italian provinces: Lecce (in Puglia) in the south (area 2,799.07 km2, inhabitants 802,082) and Brescia (in Lombardy) in the north (area 4,785.62 km2, inhabitants 1,262,678). During the study period, all new cases of FTLD (incident FTLD) were counted, and all patients9 records were reviewed. The incidence was standardized to the Italian general population in 2017. Results In the 2 provinces, 63 patients with FTLD were diagnosed. The incidence rate for FTLD was 3.05 (95% confidence interval [CI] 2.34–3.90) per 100,000 person-years (py), while the age-sex standardized incidence rate was 3.09 (95% CI 2.95–3.23) per 100,000 py. In the Italian population, the lifetime risk was 1:400. There was a progressive increase in FTLD incidence across age groups, reaching its peak in the 75- to 79-year-old group, with an incidence rate of 15.97 (95% CI 8.94–26.33) per 100,000 py. The behavioral variant of frontotemporal dementia was the most common phenotype (37%). No difference in crude incidence rate between the 2 provinces was observed. Conclusion FTLD is a more common form of dementia than previously recognized, with a risk spanning in a wide age range and with maximum incidence in the mid-70s. Improved knowledge of FTLD epidemiology will help to provide appropriate public health service policies.
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TL;DR: In this paper, a search for dark matter produced in association with top quarks in proton-proton collisions at a center-of-mass energy of 13 TeV is presented.
Abstract: A search for dark matter produced in association with top quarks in proton-proton collisions at a center-of-mass energy of 13 TeV is presented. The data set used corresponds to an integrated luminosity of 35.9 fb−1 recorded with the CMS detector at the LHC. Whereas previous searches for neutral scalar or pseudoscalar mediators considered dark matter production in association with a top quark pair only, this analysis also includes production modes with a single top quark. The results are derived from the combination of multiple selection categories that are defined to target either the single top quark or the top quark pair signature. No significant deviations with respect to the standard model predictions are observed. The results are interpreted in the context of a simplified model in which a scalar or pseudoscalar mediator particle couples to a top quark and subsequently decays into dark matter particles. Scalar and pseudoscalar mediator particles with masses below 290 and 300 GeV, respectively, are excluded at 95% confidence level, assuming a dark matter particle mass of 1 GeV and mediator couplings to fermions and dark matter particles equal to unity.
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TL;DR: In this paper, the authors reported measurements of differential cross sections for the production of two Z bosons in association with jets in proton-proton collisions at root s = 8 and 13 TeV.