10 research outputs found

    Evaluating the changes in serum parameters associated with iron metabolism in male rat exposed to Lead

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    Background: Considering the severe hazardous influences of Lead (Pb2+) on iron-related diseases, this study was carried out to evaluate the effects of Pb2+ on the serum parameters associated with iron metabolism. Materials and Methods: In this experimental study, male Wistar rats weighing 200–250 g were treated with Pb2+ for the short and long period of time. The animals received daily intraperitoneal injection of 100 mg Pb 2+ kg−1 body weight (BW) for 5 days and 4 mg Pb2+ kg−1 BW for 30 and 45 days, respectively. Results: The results showed that when animals were treated with both low and high concentrations of Pb 2+, the serum iron concentrations decreased markedly by 23.2%, 32.8%, and 39.9 % after 5, 30 and 45 days, respectively, while the sera TIBC and transferrin concentrations increased significantly (P<0.05). Following the short- and long-term exposure to Pb 2+, the percentage of serum transferrin saturation was also decreased in comparison with the untreated control group (P<0.05). Concentrations of serum copper and ceruloplasmin following Pb 2+ treatment also reduced significantly (P<0.05). Moreover, the percentage of hematocrit and hemoglobin levels was reduced (P<0.05) in all Pb 2+-treated animals in comparison with the controls. Conclusion: The results suggest that the changes in serum parameters associated with iron metabolism may play an important role in producing iron-related diseases

    Measurements of angular distance and momentum ratio distributions in three-jet and Z plus two-jet final states in pp collisions

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    Collinear (small-angle) and large-angle, as well as soft and hard radiations are investigated in three-jet and Z + two-jet events collected in proton-proton collisions at the LHC. The normalized production cross sections are measured as a function of the ratio of transverse momenta of two jets and their angular separation. The measurements in the three-jet and Z + two-jet events are based on data collected at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.8 fb(-1). The Z + two-jet events are reconstructed in the dimuon decay channel of the Z boson. The three-jet measurement is extended to include root s = 13 TeV data corresponding to an integrated luminosity of 2.3 fb(-1). The results are compared to predictions from event generators that include parton showers, multiple parton interactions, and hadronization. The collinear and soft regions are in general well described by parton showers, whereas the regions of large angular separation are often best described by calculations using higher-order matrix elements.Peer reviewe

    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 fb−1^{−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 fb−1 ^{-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 fb−1^{−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 fb−1^{-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

    Probing heavy Majorana neutrinos and the Weinberg operator through vector boson fusion processes in proton-proton collisions at s=\sqrt{s} = 13 TeV

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    The first search exploiting the vector boson fusion process to probe heavy Majorana neutrinos and the Weinberg operator at the LHC is presented. The search is performed in the same-sign dimuon final state using a proton-proton collision data set recorded at s=\sqrt{s} = 13 TeV, collected with the CMS detector and corresponding to a total integrated luminosity of 138 fb−1^{-1}. The results are found to agree with the predictions of the standard model. For heavy Majorana neutrinos, constraints on the squared mixing element between the muon and the heavy neutrino are derived in the heavy neutrino mass range 50 GeV-25 TeV; for masses above 650 GeV these are the most stringent constraints from searches at the LHC to date. A first test of the Weinberg operator at colliders provides an observed upper limit at 95% confidence level on the effective ΌΌ\mu\mu Majorana neutrino mass of 10.8 GeV.The first search exploiting the vector boson fusion process to probe heavy Majorana neutrinos and the Weinberg operator at the LHC is presented. The search is performed in the same-sign dimuon final state using a proton-proton collision dataset recorded at s=13  TeV, collected with the CMS detector and corresponding to a total integrated luminosity of 138  fb−1. The results are found to agree with the predictions of the standard model. For heavy Majorana neutrinos, constraints on the squared mixing element between the muon and the heavy neutrino are derived in the heavy neutrino mass range 50 GeV–25 TeV; for masses above 650 GeV these are the most stringent constraints from searches at the LHC to date. A first test of the Weinberg operator at colliders provides an observed upper limit at 95% confidence level on the effective ΌΌ Majorana neutrino mass of 10.8 GeV.The first search exploiting the vector boson fusion process to probe heavy Majorana neutrinos and the Weinberg operator at the LHC is presented. The search is performed in the same-sign dimuon final state using a proton-proton collision data set recorded at s\sqrt{s} = 13 TeV, collected with the CMS detector and corresponding to a total integrated luminosity of 138 fb−1^{-1}. The results are found to agree with the predictions of the standard model. For heavy Majorana neutrinos, constraints on the squared mixing element between the muon and the heavy neutrino are derived in the heavy neutrino mass range 50 GeV-25 TeV; for masses above 650 GeV these are the most stringent constraints from searches at the LHC to date. A first test of the Weinberg operator at colliders provides an observed upper limit at 95% confidence level on the effective ΌΌ\mu\mu Majorana neutrino mass of 10.8 GeV

    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 fb−1^{−1}. The inclusive fiducial cross section is measured to be σfid=73.4−5.3+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

    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 fb−1^{-1}. A 95% confidence level upper limit of 32.4 is set on the signal strength modifier ÎŒ\mu, defined as the ratio of the observed HH production rate in the HH→ZZ∗bbˉ→4ℓbbˉ{\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 Îșλ\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) <Îșλ< < \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 fb−1^{−1}. A 95% confidence level upper limit of 32.4 is set on the signal strength modifier ÎŒ, defined as the ratio of the observed HH production rate in the HH→ZZ∗bb‟→4ℓbb‟ \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 Îșλ_{λ}, defined as λHHH_{HHH} divided by its SM prediction, is constrained to be within the observed (expected) range −8.8 (−9.8) < Îșλ_{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 fb−1^{-1}. A 95% confidence level upper limit of 32.4 is set on the signal strength modifier ÎŒ\mu, defined as the ratio of the observed HH production rate in the HH →\to ZZ*bbˉ\mathrm{\bar{b}} →\to 4ℓ\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 Îșλ\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) << Îșλ\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 fb−1^{-1}. Events with two opposite-sign leptons in the final state (e+^{+}e−^{-}, ÎŒ+Ό−\mu^{+}\mu^{-}, e±Ό∓^{\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 fb−1^{−1}. Events with two opposite-sign leptons in the final state (e+^{+}e−^{−}, ÎŒ+^{+}Ό−^{−}, e±^{±}Ό∓^{∓}) 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 fb−1^{-1}. Events with two opposite-sign leptons in the final state (e+^+e−^-, ÎŒ+Ό−\mu^+\mu^-, e±Ό∓^\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

    Searches for additional Higgs bosons and for vector leptoquarks in ττ\tau\tau final states in proton-proton collisions at s=\sqrt{s} = 13 TeV

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    Three searches are presented for signatures of physics beyond the standard model (SM) in ττ\tau\tau final states in proton-proton collisions at the LHC, using a data sample collected with the CMS detector at s=\sqrt{s} = 13 TeV, corresponding to an integrated luminosity of 138 fb−1^{-1}. Upper limits at 95% confidence level (CL) are set on the products of the branching fraction for the decay into τ\tau leptons and the cross sections for the production of a new boson ϕ\phi, in addition to the H(125) boson, via gluon fusion (ggϕ\phi) or in association with b quarks, ranging from O{\mathcal{O}}(10 pb) for a mass of 60 GeV to 0.3 fb for a mass of 3.5 TeV each. The data reveal two excesses for ggϕ\phi production with local pp-values equivalent to about three standard deviations at mϕ={m_{\phi}} = 0.1 and 1.2 TeV. In a search for tt-channel exchange of a vector leptoquark U1_{1}, 95% CL upper limits are set on the dimensionless U1_{1} leptoquark coupling to quarks and τ\tau leptons ranging from 1 for a mass of 1 TeV to 6 for a mass of 5 TeV, depending on the scenario. In the interpretations of the Mh125{M_{\mathrm{h}}^{125}} and Mh, EFT125{M_{\mathrm{h},\,\text{EFT}}^{125}} minimal supersymmetric SM benchmark scenarios, additional Higgs bosons with masses below 350 GeV are excluded at 95% CL.Three searches are presented for signatures of physics beyond the standard model (SM) in ττ final states in proton-proton collisions at the LHC, using a data sample collected with the CMS detector at s \sqrt{s} = 13 TeV, corresponding to an integrated luminosity of 138 fb−1^{−1}. Upper limits at 95% confidence level (CL) are set on the products of the branching fraction for the decay into τ leptons and the cross sections for the production of a new boson ϕ, in addition to the H(125) boson, via gluon fusion (ggϕ) or in association with b quarks, ranging from O \mathcal{O} (10 pb) for a mass of 60 GeV to 0.3 fb for a mass of 3.5 TeV each. The data reveal two excesses for ggϕ production with local p-values equivalent to about three standard deviations at mϕ_{ϕ} = 0.1 and 1.2 TeV. In a search for t-channel exchange of a vector leptoquark U1_{1}, 95% CL upper limits are set on the dimensionless U1_{1} leptoquark coupling to quarks and τ leptons ranging from 1 for a mass of 1 TeV to 6 for a mass of 5 TeV, depending on the scenario. In the interpretations of the Mh125 {M}_{\textrm{h}}^{125} and Mh,EFT125 {M}_{\textrm{h},\textrm{EFT}}^{125} minimal supersymmetric SM benchmark scenarios, additional Higgs bosons with masses below 350 GeV are excluded at 95% CL.[graphic not available: see fulltext]Three searches are presented for signatures of physics beyond the standard model (SM) in ττ\tau\tau final states in proton-proton collisions at the LHC, using a data sample collected with the CMS detector at s\sqrt{s} = 13 TeV, corresponding to an integrated luminosity of 138 fb−1^{-1}. Upper limits at 95% confidence level (CL) are set on the products of the branching fraction for the decay into τ\tau leptons and the cross sections for the production of a new boson ϕ\phi, in addition to the H(125) boson, via gluon fusion (ggϕ\phi) or in association with b quarks, ranging from O\mathcal{O}(10 pb) for a mass of 60 GeV to 0.3 fb for a mass of 3.5 TeV each. The data reveal two excesses for ggϕ\phi production with local pp-values equivalent to about three standard deviations at mϕm_\phi = 0.1 and 1.2 TeV. In a search for tt-channel exchange of a vector leptoquark U1_1, 95% CL upper limits are set on the dimensionless U1_1 leptoquark coupling to quarks and τ\tau leptons ranging from 1 for a mass of 1 TeV to 6 for a mass of 5 TeV, depending on the scenario. In the interpretations of the Mh125M_\mathrm{h}^{125} and Mh,EFT125M_\mathrm{h, EFT}^{125} minimal supersymmetric SM benchmark scenarios, additional Higgs bosons with masses below 350 GeV are excluded at 95% CL
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