Search for exotic decays of the Higgs boson to a pair of pseudoscalars in the μμbb and ττbb final states

A search for exotic decays of the Higgs boson (H ) with a mass of 125Ge V to a pair of light pseudoscalars a 1 is performed in final states where one pseudoscalar decays to two b quarks and the other to a pair of muons or τ leptons. A data sample of proton-proton collisions at s = 13 Te V corresponding to an integrated luminosity of 138fb - 1 recorded with the CMS detector is analyzed. No statistically significant excess is observed over the standard model backgrounds. Upper limits are set at 95% confidence level (CL ) on the Higgs boson branching fraction to μ μ b b and to τ τ b b , via a pair of a 1 s. The limits depend on the pseudoscalar mass m a 1 and are observed to be in the range (0.17-3.3) × 10 - 4 and (1.7-7.7) × 10 - 2 in the μ μ b b and τ τ b b final states, respectively. In the framework of models with two Higgs doublets and a complex scalar singlet (2HDM+S), the results of the two final states are combined to determine upper limits on the branching fraction B ( H → a 1 a 1 → ℓ ℓ b b ) at 95% CL , with ℓ being a muon or a τ lepton. For different types of 2HDM+S, upper bounds on the branching fraction B ( H → a 1 a 1 ) are extracted from the combination of the two channels. In most of the Type II 2HDM+S parameter space, B ( H → a 1 a 1 ) values above 0.23 are excluded at 95% CL for m a 1 values between 15 and 60Ge V .

Observation of WWγ Production and Search for Hγ Production in Proton-Proton Collisions at sqrt[s]=13 TeV

The observation of WWγ production in proton-proton collisions at a center-of-mass energy of 13 TeV with an integrated luminosity of 138  fb^{-1} is presented. The observed (expected) significance is 5.6 (5.1) standard deviations. Events are selected by requiring exactly two leptons (one electron and one muon) of opposite charge, moderate missing transverse momentum, and a photon. The measured fiducial cross section for WWγ is 5.9±0.8(stat)±0.8(syst)±0.7(modeling)  fb, in agreement with the next-to-leading order quantum chromodynamics prediction. The analysis is extended with a search for the associated production of the Higgs boson and a photon, which is generated by a coupling of the Higgs boson to light quarks. The result is used to constrain the Higgs boson couplings to light quarks.

New Structures in the J/ψJ/ψ Mass Spectrum in Proton-Proton Collisions at sqrt[s]=13 TeV

A search is reported for near-threshold structures in the J/ψJ/ψ invariant mass spectrum produced in proton-proton collisions at sqrt[s]=13  TeV from data collected by the CMS experiment, corresponding to an integrated luminosity of 135  fb^{-1}. Three structures are found, and a model with quantum interference among these structures provides a good description of the data. A new structure is observed with a local significance above 5 standard deviations at a mass of 6638_{-38}^{+43}(stat)_{-31}^{+16}(syst)  MeV. Another structure with even higher significance is found at a mass of 6847_{-28}^{+44}(stat)_{-20}^{+48}(syst)  MeV, which is consistent with the X(6900) resonance reported by the LHCb experiment and confirmed by the ATLAS experiment. Evidence for another new structure, with a local significance of 4.7 standard deviations, is found at a mass of 7134_{-25}^{+48}(stat)_{-15}^{+41}(syst)  MeV. Results are also reported for a model without interference, which does not fit the data as well and shows mass shifts up to 150 MeV relative to the model with interference.

Search for Scalar Leptoquarks Produced via τ-Lepton-Quark Scattering in pp Collisions at sqrt[s]=13 TeV

The first search for scalar leptoquarks produced in τ-lepton-quark collisions is presented. It is based on a set of proton-proton collision data recorded with the CMS detector at the LHC at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 138  fb^{-1}. The reconstructed final state consists of a jet, significant missing transverse momentum, and a τ lepton reconstructed through its hadronic or leptonic decays. Limits are set on the product of the leptoquark production cross section and branching fraction and interpreted as exclusions in the plane of the leptoquark mass and the leptoquark-τ-quark coupling strength.

Search for Inelastic Dark Matter in Events with Two Displaced Muons and Missing Transverse Momentum in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for dark matter in events with a displaced nonresonant muon pair and missing transverse momentum is presented. The analysis is performed using an integrated luminosity of 138  fb^{-1} of proton-proton (pp) collision data at a center-of-mass energy of 13 TeV produced by the LHC in 2016-2018. No significant excess over the predicted backgrounds is observed. Upper limits are set on the product of the inelastic dark matter production cross section σ(pp→A^{'}→χ_{1}χ_{2}) and the decay branching fraction B(χ_{2}→χ_{1}μ^{+}μ^{-}), where A^{'} is a dark photon and χ_{1} and χ_{2} are states in the dark sector with near mass degeneracy. This is the first dedicated collider search for inelastic dark matter.

Luminosity determination using Z boson production at the CMS experiment

The measurement of Z boson production is presented as a method to determine the integrated luminosity of CMS data sets. The analysis uses proton-proton collision data, recorded by the CMS experiment at the CERN LHC in 2017 at a center-of-mass energy of 13Te V . Events with Z bosons decaying into a pair of muons are selected. The total number of Z bosons produced in a fiducial volume is determined, together with the identification efficiencies and correlations from the same data set, in small intervals of 20pb - 1 of integrated luminosity, thus facilitating the efficiency and rate measurement as a function of time and instantaneous luminosity. Using the ratio of the efficiency-corrected numbers of Z bosons, the precisely measured integrated luminosity of one data set is used to determine the luminosity of another. For the first time, a full quantitative uncertainty analysis of the use of Z  bosons for the integrated luminosity measurement is performed. The uncertainty in the extrapolation between two data sets, recorded in 2017 at low and high instantaneous luminosity, is less than 0.5%. We show that the Z boson rate measurement constitutes a precise method, complementary to traditional methods, with the potential to improve the measurement of the integrated luminosity.

Measurement of the production cross section for a W boson in association with a charm quark in proton-proton collisions at s=13TeV

The strange quark content of the proton is probed through the measurement of the production cross section for a W boson and a charm (c) quark in proton-proton collisions at a center-of-mass energy of 13Te V . The analysis uses a data sample corresponding to a total integrated luminosity of 138fb - 1 collected with the CMS detector at the LHC. The W bosons are identified through their leptonic decays to an electron or a muon, and a neutrino. Charm jets are tagged using the presence of a muon or a secondary vertex inside the jet. The W + c production cross section and the cross section ratio R c ± = σ ( W + + c ¯ ) / σ ( W - + c ) are measured inclusively and differentially as functions of the transverse momentum and the pseudorapidity of the lepton originating from the W boson decay. The precision of the measurements is improved with respect to previous studies, reaching 1% in R c ± = 0.950 ± 0.005 (stat) ± 0.010 (syst) . The measurements are compared with theoretical predictions up to next-to-next-to-leading order in perturbative quantum chromodynamics.

Probing Small Bjorken-x Nuclear Gluonic Structure via Coherent J/ψ Photoproduction in Ultraperipheral Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

Quasireal photons exchanged in relativistic heavy ion interactions are powerful probes of the gluonic structure of nuclei. The coherent J/ψ photoproduction cross section in ultraperipheral lead-lead collisions is measured as a function of photon-nucleus center-of-mass energies per nucleon (W_{γN}^{Pb}) over a wide range of 40 Collapse

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Measurement of the top quark mass using a profile likelihood approach with the lepton + jets final states in proton-proton collisions at s=13TeV

The mass of the top quark is measured in 36.3fb - 1 of LHC proton-proton collision data collected with the CMS detector at s = 13 Te V . The measurement uses a sample of top quark pair candidate events containing one isolated electron or muon and at least four jets in the final state. For each event, the mass is reconstructed from a kinematic fit of the decay products to a top quark pair hypothesis. A profile likelihood method is applied using up to four observables per event to extract the top quark mass. The top quark mass is measured to be 171.77 ± 0.37 Ge V . This approach significantly improves the precision over previous measurements.

A search for decays of the Higgs boson to invisible particles in events with a top-antitop quark pair or a vector boson in proton-proton collisions at s=13TeV

A search for decays to invisible particles of Higgs bosons produced in association with a top-antitop quark pair or a vector boson, which both decay to a fully hadronic final state, has been performed using proton-proton collision data collected at s = 13 Te V by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138fb - 1 . The 95% confidence level upper limit set on the branching fraction of the 125Ge V Higgs boson to invisible particles, B ( H → inv ) , is 0.54 (0.39 expected), assuming standard model production cross sections. The results of this analysis are combined with previous B ( H → inv ) searches carried out at s = 7 , 8, and 13Te V in complementary production modes. The combined upper limit at 95% confidence level on B ( H → inv ) is 0.15 (0.08 expected).

Observation of τ Lepton Pair Production in Ultraperipheral Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

We present an observation of photon-photon production of τ lepton pairs in ultraperipheral lead-lead collisions. The measurement is based on a data sample with an integrated luminosity of 404  μb^{-1} collected by the CMS experiment at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=5.02  TeV. The γγ→τ^{+}τ^{-} process is observed for τ^{+}τ^{-} events with a muon and three charged hadrons in the final state. The measured fiducial cross section is σ(γγ→τ^{+}τ^{-})=4.8±0.6(stat)±0.5(syst)  μb, where the second (third) term corresponds to the statistical (systematic) uncertainty in σ(γγ→τ^{+}τ^{-}) in agreement with leading-order QED predictions. Using σ(γγ→τ^{+}τ^{-}), we estimate a model-dependent value of the anomalous magnetic moment of the τ lepton of a_{τ}=0.001_{-0.089}^{+0.055}.

Measurement of the Dependence of the Hadron Production Fraction Ratios f_{s}/f_{u} and f_{d}/f_{u} on B Meson Kinematic Variables in Proton-Proton Collisions at sqrt[s]=13 TeV

The dependence of the ratio between the B_{s}^{0} and B^{+} hadron production fractions, f_{s}/f_{u}, on the transverse momentum (p_{T}) and rapidity of the B mesons is studied using the decay channels B_{s}^{0}→J/ψϕ and B^{+}→J/ψK^{+}. The analysis uses a data 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 61.6  fb^{-1}. The f_{s}/f_{u} ratio is observed to depend on the B p_{T} and to be consistent with becoming asymptotically constant at large p_{T}. No rapidity dependence is observed. The ratio of the B^{0} to B^{+} meson production fractions, f_{d}/f_{u}, is also measured, for the first time in proton-proton collisions, using the B^{0}→J/ψK^{*0} decay channel. The result is found to be within 1 standard deviation of unity and independent of p_{T} and rapidity, as expected from isospin invariance.

Search for Exotic Higgs Boson Decays H→AA→4γ with Events Containing Two Merged Diphotons in Proton-Proton Collisions at sqrt[s]=13 TeV

We present the first direct search for exotic Higgs boson decays H→AA, A→γγ in events with two photonlike objects. The hypothetical particle A is a low-mass spin-0 particle decaying promptly to a merged diphoton reconstructed as a single photonlike object. We analyze the data collected by the CMS experiment at sqrt[s]=13  TeV corresponding to an integrated luminosity of 136  fb^{-1}. No excess above the estimated background is found. We set upper limits on the branching fraction B(H→AA→4γ) of (0.9-3.3)×10^{-3} at 95% confidence level for masses of A in the range 0.1-1.2 GeV.

Observation of Same-Sign WW Production from Double Parton Scattering in Proton-Proton Collisions at sqrt[s]=13 TeV

The first observation of the production of W^{±}W^{±} bosons from double parton scattering processes using same-sign electron-muon and dimuon events in proton-proton collisions is reported. The data sample corresponds to an integrated luminosity of 138  fb^{-1} recorded at a center-of-mass energy of 13 TeV using the CMS detector at the CERN LHC. Multivariate discriminants are used to distinguish the signal process from the main backgrounds. A binned maximum likelihood fit is performed to extract the signal cross section. The measured cross section for production of same-sign W bosons decaying leptonically is 80.7±11.2(stat) _{-8.6}^{+9.5}(syst)±12.1(model)  fb, whereas the measured fiducial cross section is 6.28±0.81(stat)±0.69(syst)±0.37(model)  fb. The observed significance of the signal is 6.2 standard deviations above the background-only hypothesis.

Observation of the Rare Decay of the η Meson to Four Muons

A search for the rare η→μ^{+}μ^{-}μ^{+}μ^{-} double-Dalitz decay is performed using a sample of proton-proton collisions, collected by the CMS experiment at the CERN LHC with high-rate muon triggers during 2017 and 2018 and corresponding to an integrated luminosity of 101  fb^{-1}. A signal having a statistical significance well in excess of 5 standard deviations is observed. Using the η→μ^{+}μ^{-} decay as normalization, the branching fraction B(η→μ^{+}μ^{-}μ^{+}μ^{-})=[5.0±0.8(stat)±0.7(syst)±0.7(B_{2μ})]×10^{-9} is measured, where the last term is the uncertainty in the normalization channel branching fraction. This work achieves an improved precision of over 5 orders of magnitude compared to previous results, leading to the first measurement of this branching fraction, which is found to agree with theoretical predictions.

Measurements of jet multiplicity and jet transverse momentum in multijet events in proton-proton collisions at s=13TeV

Multijet events at large transverse momentum (p T ) are measured at s = 13 Te V using data recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of 36.3 fb - 1 . The multiplicity of jets with p T > 50 Ge V that are produced in association with a high-p T dijet system is measured in various ranges of the p T of the jet with the highest transverse momentum and as a function of the azimuthal angle difference Δ ϕ 1 , 2 between the two highest p T jets in the dijet system. The differential production cross sections are measured as a function of the transverse momenta of the four highest p T jets. The measurements are compared with leading and next-to-leading order matrix element calculations supplemented with simulations of parton shower, hadronization, and multiparton interactions. In addition, the measurements are compared with next-to-leading order matrix element calculations combined with transverse-momentum dependent parton densities and transverse-momentum dependent parton shower.

[Chest hemorrhage after left total pulmonary resection for secondary rifampin-resistant tuberculosis:a case report]

The patient had received five courses of anti-tuberculosis treatment for recurrent tuberculosis. The drug sensitivity test results of the first three courses showed drug-sensitive pulmonary tuberculosis, and the fourth diagnosis was rifampin-resistant tuberculosis (RR-TB), complicated by chronic obstructive pulmonary disease, type Ⅱ respiratory failure, pulmonary heart disease, and heart failure (grade Ⅲ). The patient stopped taking the anti-tuberculosis drugs on his own in the eighth month of receiving the resistant treatment. After admission, the symptoms improved temporarily after receiving oxygen therapy, anti-infection, and anti-tuberculosis treatment. Because of hemoptysis, the patient underwent arterial embolization by catheterization, but a large amount of hemoptysis occurred shortly thereafter. Emergency left total lung resection and gauze packing for hemostasis were performed. After surgery, the patient's vital signs were maintained with mechanical ventilation and vasopressors. Forty-eight hours after surgery, the gauze was removed, and the patient underwent tracheotomy, enteral nutrition, and anti-tuberculosis treatment. After discharge, the patient underwent rehabilitative exercise and anti-resistant tuberculosis therapy. The patient's condition remained stable for more than six months of follow-up.

Azimuthal correlations in Z +jets events in proton-proton collisions at s=13TeV

The production of Z bosons associated with jets is measured in pp collisions at s = 13 Te V with data recorded with the CMS experiment at the LHC corresponding to an integrated luminosity of 36.3fb - 1 . The multiplicity of jets with transverse momentum p T > 30 Ge V is measured for different regions of the Z boson's p T ( Z ) , from lower than 10Ge V to higher than 100Ge V . The azimuthal correlation Δ ϕ between the Z boson and the leading jet, as well as the correlations between the two leading jets are measured in three regions of p T ( Z ) . The measurements are compared with several predictions at leading and next-to-leading orders, interfaced with parton showers. Predictions based on transverse-momentum dependent parton distributions and corresponding parton showers give a good description of the measurement in the regions where multiple parton interactions and higher jet multiplicities are not important. The effects of multiple parton interactions are shown to be important to correctly describe the measured spectra in the low p T ( Z ) regions.

Search for Higgs Boson Decay to a Charm Quark-Antiquark Pair in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for the standard model Higgs boson decaying to a charm quark-antiquark pair, H→cc[over ¯], produced in association with a leptonically decaying V (W or Z) boson is presented. The search is performed with proton-proton collisions at sqrt[s]=13  TeV collected by the CMS experiment, corresponding to an integrated luminosity of 138  fb^{-1}. Novel charm jet identification and analysis methods using machine learning techniques are employed. The analysis is validated by searching for Z→cc[over ¯] in VZ events, leading to its first observation at a hadron collider with a significance of 5.7 standard deviations. The observed (expected) upper limit on σ(VH)B(H→cc[over ¯]) is 0.94 (0.50_{-0.15}^{+0.22})pb at 95% confidence level (C.L.), corresponding to 14 (7.6_{-2.3}^{+3.4}) times the standard model prediction. For the Higgs-charm Yukawa coupling modifier, κ_{c}, the observed (expected) 95% C.L. interval is 1.1<|κ_{c}|<5.5 (|κ_{c}|<3.4), the most stringent constraint to date.

Search for Nonresonant Pair Production of Highly Energetic Higgs Bosons Decaying to Bottom Quarks

A search for nonresonant Higgs boson (H) pair production via gluon and vector boson (V) fusion is performed in the four-bottom-quark final state, using proton-proton collision data at 13 TeV corresponding to 138  fb^{-1} collected by the CMS experiment at the LHC. The analysis targets Lorentz-boosted H pairs identified using a graph neural network. It constrains the strengths relative to the standard model of the H self-coupling and the quartic VVHH couplings, κ_{2V}, excluding κ_{2V}=0 for the first time, with a significance of 6.3 standard deviations when other H couplings are fixed to their standard model values.

Search for Higgs Boson and Observation of Z Boson through Their Decay into a Charm Quark-Antiquark Pair in Boosted Topologies in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for the standard model (SM) Higgs boson (H) produced with transverse momentum (p_{T}) greater than 450 GeV and decaying to a charm quark-antiquark (cc[over ¯]) pair is presented. The search is performed using proton-proton collision data collected at sqrt[s]=13  TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138  fb^{-1}. Boosted H→cc[over ¯] decay products are reconstructed as a single large-radius jet and identified using a deep neural network charm tagging technique. The method is validated by measuring the Z→cc[over ¯] decay process, which is observed in association with jets at high p_{T} for the first time with a signal strength of 1.00_{-0.14}^{+0.17}(syst)±0.08(theo)±0.06(stat), defined as the ratio of the observed process rate to the SM expectation. The observed (expected) upper limit on σ(H)B(H→cc[over ¯]) is set at 47 (39) times the SM prediction at 95% confidence level.

Measurements of the Higgs boson production cross section and couplings in the W boson pair decay channel in proton-proton collisions at s=13TeV

Production cross sections of the standard model Higgs boson decaying to a pair of W bosons are measured in proton-proton collisions at a center-of-mass energy of 13Te V . The analysis targets Higgs bosons produced via gluon fusion, vector boson fusion, and in association with a W or Z boson. Candidate events are required to have at least two charged leptons and moderate missing transverse momentum, targeting events with at least one leptonically decaying W boson originating from the Higgs boson. Results are presented in the form of inclusive and differential cross sections in the simplified template cross section framework, as well as couplings of the Higgs boson to vector bosons and fermions. The data set collected by the CMS detector during 2016-2018 is used, corresponding to an integrated luminosity of 138fb - 1 . The signal strength modifier μ , defined as the ratio of the observed production rate in a given decay channel to the standard model expectation, is measured to be μ = 0 . 95 - 0.09 + 0.10 . All results are found to be compatible with the standard model within the uncertainties.

Measurement of the mass dependence of the transverse momentum of lepton pairs in Drell-Yan production in proton-proton collisions at s=13TeV

The double differential cross sections of the Drell-Yan lepton pair (ℓ + ℓ - , dielectron or dimuon) production are measured as functions of the invariant mass m ℓ ℓ , transverse momentum p T ( ℓ ℓ ) , and φ η ∗ . The φ η ∗ observable, derived from angular measurements of the leptons and highly correlated with p T ( ℓ ℓ ) , is used to probe the low-p T ( ℓ ℓ ) region in a complementary way. Dilepton masses up to 1Te V are investigated. Additionally, a measurement is performed requiring at least one jet in the final state. To benefit from partial cancellation of the systematic uncertainty, the ratios of the differential cross sections for various m ℓ ℓ ranges to those in the Z mass peak interval are presented. The collected data correspond to an integrated luminosity of 36.3fb - 1 of proton-proton collisions recorded with the CMS detector at the LHC at a centre-of-mass energy of 13Te V . Measurements are compared with predictions based on perturbative quantum chromodynamics, including soft-gluon resummation.

CMS pythia 8 colour reconnection tunes based on underlying-event data

New sets of parameter tunes for two of the colour reconnection models, quantum chromodynamics-inspired and gluon-move, implemented in the pythia  8 event generator, are obtained based on the default CMS pythia  8 underlying-event tune, CP5. Measurements sensitive to the underlying event performed by the CMS experiment at centre-of-mass energies s = 7 and 13Te V , and by the CDF experiment at 1.96Te V are used to constrain the parameters of colour reconnection models and multiple-parton interactions simultaneously. The new colour reconnection tunes are compared with various measurements at 1.96, 7, 8, and 13Te V including measurements of the underlying-event, strange-particle multiplicities, jet substructure observables, jet shapes, and colour flow in top quark pair (t t ¯ ) events. The new tunes are also used to estimate the uncertainty related to colour reconnection modelling in the top quark mass measurement using the decay products of t t ¯ events in the semileptonic channel at 13Te V .

Probing Heavy Majorana Neutrinos and the Weinberg Operator through Vector Boson Fusion Processes in Proton-Proton Collisions at sqrt[s]=13 TeV

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 sqrt[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 μμ Majorana neutrino mass of 10.8 GeV.

Search for light Higgs bosons from supersymmetric cascade decays in pp collisions at s=13TeV

A search is reported for pairs of light Higgs bosons (H 1 ) produced in supersymmetric cascade decays in final states with small missing transverse momentum. A data set of LHC pp collisions collected with the CMS detector at s = 13 TeV and corresponding to an integrated luminosity of 138fb - 1 is used. The search targets events where both H 1 bosons decay into pairs that are reconstructed as large-radius jets using substructure techniques. No evidence is found for an excess of events beyond the background expectations of the standard model (SM). Results from the search are interpreted in the next-to-minimal supersymmetric extension of the SM, where a "singlino" of small mass leads to squark and gluino cascade decays that can predominantly end in a highly Lorentz-boosted singlet-like H 1 and a singlino-like neutralino of small transverse momentum. Upper limits are set on the product of the squark or gluino pair production cross section and the square of the branching fraction of the H 1 in a benchmark model containing almost mass-degenerate gluinos and light-flavour squarks. Under the assumption of an SM-like branching fraction, H 1 bosons with masses in the range 40-120GeV arising from the decays of squarks or gluinos with a mass of 1200-2500GeV are excluded at 95% confidence level.

Measurement of the differential tt¯ production cross section as a function of the jet mass and extraction of the top quark mass in hadronic decays of boosted top quarks

A measurement of the jet mass distribution in hadronic decays of Lorentz-boosted top quarks is presented. The measurement is performed in the lepton + jets channel of top quark pair production (t t ¯ ) events, where the lepton is an electron or muon. The products of the hadronic top quark decay are reconstructed using a single large-radius jet with transverse momentum greater than 400Ge V . The data were collected with the CMS detector at the LHC in proton-proton collisions and correspond to an integrated luminosity of 138fb - 1 . The differential t t ¯ production cross section as a function of the jet mass is unfolded to the particle level and is used to extract the top quark mass. The jet mass scale is calibrated using the hadronic W boson decay within the large-radius jet. The uncertainties in the modelling of the final state radiation are reduced by studying angular correlations in the jet substructure. These developments lead to a significant increase in precision, and a top quark mass of 173.06 ± 0.84 Ge V .

[Efficacy and safety of epidermal growth factor receptor tyrosine kinase inhibitors combined with chemotherapy as first-line treatment for epidermal growth factor receptor-mutant advanced non-small cell lung cancer]

Objective: To observe the clinical efficacy and safety of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) combined with chemotherapy as first-line treatment for EGFR mutant advanced non-small cell lung cancer (NSCLC). Methods: It was a retrospective, single-arm real-world study and a total of 39 patients with stage ⅢB to Ⅳ EGFR mutant NSCLC diagnosed in Cancer Hospital of Chinese Academy of Medical Sciences from July 2018 to December 2020 were collected. There were 16 males and 23 females, the age ranged from 25 to 73 years, with a median age of 53 years. All patients received EGFR-TKIs synchronously combined with pemetrexed and platinum-containing chemotherapy for 4-6 cycles as first-line treatment, followed by EGFR-TKI monotherapy with or without pemetrexed maintenance therapy. The objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS) and adverse reactions were evaluated. Median follow-up time was 18.6 months (95%CI: 16.2-21.0 months). The Kaplan-Meier method was used for survival analysis. Results: The ORR was 61.5% (24/39), the DCR was 94.9% (37/39) and the median PFS was 16.4 months (95%CI: 12.1-20.7 months). The main adverse reactions were liver function injury (59.0%, 23/39), myelosuppression (43.6%, 17/39), skin reaction (25.6%, 10/39), gastrointestinal reaction (17.9%, 7/39), fatigue (12.8%, 5/39) and kidney injury (5.1%, 2/39). Most of the patients had grade 1-2 adverse reactions, and the rate of grade 3 adverse events were 12.8%(5/39), which were effectively alleviated after symptomatic support treatment, no grade 4 serious adverse events occurred. Conclusion: EGFR-TKIs synchronously combined with chemotherapy followed by EGFR-TKI monotherapy with or without pemetrexed maintenance therapy has a certain therapeutic effect and fairly good safety, which can prolong PFS in patients with EGFR mutated advanced NSCLC.

Assessment of proline function in higher plants under extreme temperatures

Climate change and abiotic stress factors are key players in crop losses worldwide. Among which, extreme temperatures (heat and cold) disturb plant growth and development, reduce productivity and, in severe cases, lead to plant death. Plants have developed numerous strategies to mitigate the detrimental impact of temperature stress. Exposure to stress leads to the accumulation of various metabolites, e.g. sugars, sugar alcohols, organic acids and amino acids. Plants accumulate the amino acid 'proline' in response to several abiotic stresses, including temperature stress. Proline abundance may result from de novo synthesis, hydrolysis of proteins, reduced utilization or degradation. Proline also leads to stress tolerance by maintaining the osmotic balance (still controversial), cell turgidity and indirectly modulating metabolism of reactive oxygen species. Furthermore, the crosstalk of proline with other osmoprotectants and signalling molecules, e.g. glycine betaine, abscisic acid, nitric oxide, hydrogen sulfide, soluble sugars, helps to strengthen protective mechanisms in stressful environments. Development of less temperature-responsive cultivars can be achieved by manipulating the biosynthesis of proline through genetic engineering. This review presents an overview of plant responses to extreme temperatures and an outline of proline metabolism under such temperatures. The exogenous application of proline as a protective molecule under extreme temperatures is also presented. Proline crosstalk and interaction with other molecules is also discussed. Finally, the potential of genetic engineering of proline-related genes is explained to develop 'temperature-smart' plants. In short, exogenous application of proline and genetic engineering of proline genes promise ways forward for developing 'temperature-smart' future crop plants.

Simulation Experiment Research of Mine Roadway Simulating Test Device with Adjustable Wind Velocity and Temperature and Humidity

The design and development process of wind velocity sensors for mining has been a challenging task due to the complexity of a large number of field tests. To resolve this problem, this study aimed to provide a comprehensive test device for the design and development of high-precision wind velocities sensor for mining. Through a combination of experiments and computational fluid dynamics (CFD), a device that can simulate the mine roadway environment was developed. The device can control the temperature, humidity, and wind velocity parameters to fully replicate the mine roadway environment. It gives designers and developers of high-precision wind velocity sensors for mining a rational and scientific testing environment. In order to quantitatively define the uniformity of air flow in the mine highway section, the research introduced the non-uniformity determination method. The approach was expanded to assess the cross-sectional uniformity of temperature and humidity. The wind velocity within the machine can increase to 8.5 m/s by selecting the right kind of fan. The minimum wind velocity non-uniformity at this moment is 2.30%. The device's internal temperature can be raised to 38.23 °C and its humidity level can be increased to 95.09% by carefully crafting the rectifier orifice plate's structure. At this time, the lowest temperature non-uniformity is 2.22%, and the lowest humidity non-uniformity is 2.40%. The device's average wind velocity is 4.37 m/s, its average temperature is 37.7 °C, as well as its average humidity is 95%, per the emulate results. The device's non-uniformity in wind velocity, temperature, and humidity is 2.89%, 1.34%, and 2.23%, respectively. It is capable of simulating the mine roadway environment in its entirety.

Genome-wide identification and validation of tomato-encoded sRNA as the cross-species antifungal factors targeting the virulence genes of Botrytis cinerea

Recent evidence shows that small RNAs are transferred from a species to another through cross-species transmission and exhibit biological activities in the receptor. In this study, we focused on tomato-derived sRNAs play a role of defense against Botrytis cinerea. Bioinformatics method was firstly employed to identify tomato-encoded sRNAs as the cross-species antifungal factors targeting B. cinerea genes. Then the expression levels of some identifed sRNAs were checked in B. cinerea-infected plant using qRT-PCR method. Exogenic RNA-induced gene silences analysis were performed to investigate the antifungal roles of the sRNAs, and the target genes in B. cinerea of antifungal sRNAs would be confirmed by using co-expression analysis. Results showed that a total of 21 B.cinerea-induced sRNAs with high abundance were identified as the cross-kingdom regulator candidates. Among them, three sRNAs containing a miRNA (miR396a-5p) and two siRNA (siR3 and siR14) were selected for experimental validation and bioassay analysis. qRT-PCR confirmed that all of these 3 sRNAs were induced in tomato leaves by B. cinerea infection. Correspondingly, 4 virulence genes of B. cinerea respectively targeted by these 3 sRNAs were down-regulated. Bioassay revealed that all of these 3 cross-species sRNAs could inhibit the virulence and spore gemination of B. cinerea. Correspondingly, the coding genes of B. cinerea targeted by these sRNAs were also down-regulated. Moreover, the virulence inhibition by double strand sRNA was more effective than that by single strand sRNA. The inhibition efficiency of sRNA against B. cinerea increased with the increase of its concentration. Our findings provide new evidence into the coevolution of pathogens and host plants, as well as new directions for the use of plant-derived sRNAs to control pathogens.

[Applications of collagen extrafibrillar demineralization in dentin bonding]

The existing dentin bonding systems based on acid-etching technique lead to the loss of both extrafibrillar and intrafibrillar minerals from dentin collagen, causing excessive demineralization. Because resin monomers can not infiltrate the intrafibrillar spaces of demineralized collagen matrix, degradation of exposed collagen and resin hydrolysis subsequently occur within the hybrid layer, which seriously jeopardizing the longevity of resin-dentin bonding. Collagen extrafibrillar demineralization can effectively avoid the structural defects within the resin-dentin interface caused by acid-etching technique and improve the durability of resin-dentin bonding, by preserving intrafibrillar minerals and selectively demineralizing extrafibrillar dentin. The mechanism and research progress of collagen extrafibrillar demineralization in dentin bonding are reviewed in the paper.

[Prevalence and risk factors of hookworm infections among vegetable growers in Anhui Province from 2018 to 2019]

OBJECTIVE

To investigate the prevalence and risk factors of hookworm infections among vegetable growers in Anhui Province, so as to provide the evidence for formulating the control strategy and interventions for hookworm human infections.

METHODS

A total of 1 179 vegetable growers were randomly sampled from 7 counties in Anhui province according to the natural ecological function areas in 2018 and 2019, and the basic features and risk factors of hookworm infections were collected from all subjects using a self-designed questionnaire, including living environment, vegetable planting and fertilization, type of household crops, animal feeding, hygiene and labor habits. In addition, stool samples were collected from all participants, and each stool sample was subjected to twice tests with the Kato-Katz technique. The risk factors of hookworm infections were identified among vegetable growers with the Bayesian log-binomial regression model.

RESULTS

The prevalence of hookworm infection was 3.90% among the 1 179 vegetable growers. The prevalence of hookworm infection was 10.07% (15/149) among unemployed subjects, 5.32% (31/583) among farmers, and 0 among full-time vegetable growers (0/377) and subjects with other occupations (0/70), and there was a significant difference among subjects in terms of occupation (χ²=36.37, P < 0.01). Bayesian log-binomial regression analysis showed that fertilization with human feces [relative risk (RR)=18.25, 95% confidence interval (CI): (4.31, 77.17)], barefoot labor in vegetable fields [RR=2.86, 95% CI: (1.43, 5.70)], and living in plain ecological areas along the middle and lower reaches of the Yangtze River [RR=4.19, 95% CI: (1.19, 14.81)] were independent risk factors of hookworm infections among vegetable growers. Stratified analysis showed that fertilization with human feces, barefoot labor in vegetable fields, drinking well water or mountain spring, and living in plain ecological areas along the middle and lower reaches of the Yangtze River were independent risk factors of hookw, orm infection among farmers, and living in plain ecological areas along the middle and lower reaches of the Yangtze River and growing rice were independent risk factors of hookw, orm infection among unemployed individuals.

CONCLUSIONS

The prevalence of hookworm infection is high among vegetable growers in Anhui Province, and fertilization with human feces, barefoot labor in vegetable fields and living in plain ecological areas along the middle and lower reaches of the Yangtze River are risk factors of hookw, orm infections among vegetable growers.

Search for Higgs Boson Pair Production in the Four b Quark Final State in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for pairs of Higgs bosons produced via gluon and vector boson fusion is presented, focusing on the four b quark final state. The data sample consists of proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the CMS detector at the LHC, and corresponds to an integrated luminosity of 138  fb^{-1}. No deviation from the background-only hypothesis is observed. A 95% confidence level upper limit on the Higgs boson pair production cross section is observed at 3.9 times the standard model prediction for an expected value of 7.8. Constraints are also set on the modifiers of the Higgs field self-coupling, κ_{λ}, and of the coupling of two Higgs bosons to two vector bosons, κ_{2 V}. The observed (expected) allowed intervals at the 95% confidence level are -2.3<κ_{λ}<9.4 (-5.0<κ_{λ}<12.0) and -0.1<κ_{2 V}<2.2 (-0.4<κ_{2 V}<2.5). These are the most stringent observed constraints to date on the HH production cross section and on the κ_{2 V } coupling.

Search for Flavor-Changing Neutral Current Interactions of the Top Quark and Higgs Boson in Final States with Two Photons in Proton-Proton Collisions at sqrt[s]=13 TeV

Proton-proton interactions resulting in final states with two photons are studied in a search for the signature of flavor-changing neutral current interactions of top quarks (t) and Higgs bosons (H). The analysis is based on data collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 137  fb^{-1}. No significant excess above the background prediction is observed. Upper limits on the branching fractions (B) of the top quark decaying to a Higgs boson and an up (u) or charm (c) quark are derived through a binned fit to the diphoton invariant mass spectrum. The observed (expected) 95% confidence level upper limits are found to be 0.019% (0.031%) for B(t→Hu) and 0.073% (0.051%) for B(t→Hc). These are the strictest upper limits yet determined.

A portrait of the Higgs boson by the CMS experiment ten years after the discovery

In July 2012, the ATLAS and CMS collaborations at the CERN Large Hadron Collider announced the observation of a Higgs boson at a mass of around 125 gigaelectronvolts. Ten years later, and with the data corresponding to the production of a 30-times larger number of Higgs bosons, we have learnt much more about the properties of the Higgs boson. The CMS experiment has observed the Higgs boson in numerous fermionic and bosonic decay channels, established its spin-parity quantum numbers, determined its mass and measured its production cross-sections in various modes. Here the CMS Collaboration reports the most up-to-date combination of results on the properties of the Higgs boson, including the most stringent limit on the cross-section for the production of a pair of Higgs bosons, on the basis of data from proton-proton collisions at a centre-of-mass energy of 13 teraelectronvolts. Within the uncertainties, all these observations are compatible with the predictions of the standard model of elementary particle physics. Much evidence points to the fact that the standard model is a low-energy approximation of a more comprehensive theory. Several of the standard model issues originate in the sector of Higgs boson physics. An order of magnitude larger number of Higgs bosons, expected to be examined over the next 15 years, will help deepen our understanding of this crucial sector.

Observation of the B_{c}^{+} Meson in Pb-Pb and pp Collisions at sqrt[s_{NN}]=5.02 TeV and Measurement of its Nuclear Modification Factor

The B_{c}^{+} meson is observed for the first time in heavy ion collisions. Data from the CMS detector are used to study the production of the B_{c}^{+} meson in lead-lead (Pb-Pb) and proton-proton (pp) collisions at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=5.02  TeV, via the B_{c}^{+}→(J/ψ→μ^{+}μ^{-})μ^{+}ν_{μ} decay. The B_{c}^{+} nuclear modification factor, derived from the Pb-Pb-to-pp ratio of production cross sections, is measured in two bins of the trimuon transverse momentum and of the Pb-Pb collision centrality. The B_{c}^{+} meson is shown to be less suppressed than quarkonia and most of the open heavy-flavor mesons, suggesting that effects of the hot and dense nuclear matter created in heavy ion collisions contribute to its production. This measurement sets forth a promising new probe of the interplay of suppression and enhancement mechanisms in the production of heavy-flavor mesons in the quark-gluon plasma.

Observation of B 0 → ψ (2S)K S 0 π + π - and B s 0 → ψ (2S)K S 0 decays

Using a data sample of s = 13 TeV proton-proton collisions collected by the CMS experiment at the LHC in 2017 and 2018 with an integrated luminosity of 103 fb - 1 , the B s 0 → ψ ( 2S ) K S 0 and B 0 → ψ ( 2S ) K S 0 π + π - decays are observed with significances exceeding 5 standard deviations. The resulting branching fraction ratios, measured for the first time, correspond to B ( B s 0 → ψ ( 2S ) K S 0 ) / B ( B 0 → ψ ( 2S ) K S 0 ) = ( 3.33 ± 0.69 ( stat ) ± 0.11 ( syst ) ± 0.34 ( f s / f d ) ) × 10 - 2 and B ( B 0 → ψ ( 2S ) K S 0 π + π - ) / B ( B 0 → ψ ( 2S ) K S 0 ) = 0.480 ± 0.013 ( stat ) ± 0.032 ( syst ) , where the last uncertainty in the first ratio is related to the uncertainty in the ratio of production cross sections of B s 0 and B 0 mesons, f s / f d .

Analysis of miRNAs responsive to long-term calcium deficiency in tef (Eragrostis tef (Zucc.) Trotter)

MicroRNAs (miRNAs) play an important role in growth, development, stress resilience, and epigenetic modifications of plants. However, the effect of calcium (Ca²⁺) deficiency on miRNA expression in the orphan crop tef (Eragrostis tef) remains unknown. In this study, we analyzed expression of miRNAs in roots and shoots of tef in response to Ca²⁺ treatment. miRNA-seq followed by bioinformatic analysis allowed us to identify a large number of small RNAs (sRNAs) ranging from 17 to 35 nt in length. A total of 1380 miRNAs were identified in tef experiencing long-term Ca²⁺ deficiency while 1495 miRNAs were detected in control plants. Among the miRNAs identified in this study, 161 miRNAs were similar with those previously characterized in other plant species and 348 miRNAs were novel, while the remaining miRNAs were uncharacterized. Putative target genes and their functions were predicted for all the known and novel miRNAs that we identified. Based on gene ontology (GO) analysis, the predicted target genes are known to have various biological and molecular functions including calcium uptake and transport. Pairwise comparison of differentially expressed miRNAs revealed that some miRNAs were specifically enriched in roots or shoots of low Ca²⁺-treated plants. Further characterization of the miRNAs and their targets identified in this study may help in understanding Ca²⁺ deficiency responses in tef and related orphan crops.

Probing Flat Band Physics in Spin Ice Systems via Polarized Neutron Scattering

In this Letter, we illustrate how polarized neutron scattering can be used to isolate the spin-spin correlations of modes forming flat bands in a frustrated magnetic system hosting a classical spin liquid phase. In particular, we explain why the nearest-neighbor spin ice model, whose interaction matrix has two flat bands, produces a dispersionless (i.e., "flat") response in the non-spin-flip (NSF) polarized neutron scattering channel and demonstrate that NSF scattering is a highly sensitive probe of correlations induced by weak perturbations that lift the flat band degeneracy. We use this to explain the experimentally measured dispersive (i.e., nonflat) NSF channel of the dipolar spin ice compound Ho_{2}Ti_{2}O_{7}.

Measurement of the Inclusive and Differential Higgs Boson Production Cross Sections in the Decay Mode to a Pair of τ Leptons in pp Collisions at sqrt[s]=13 TeV

Measurements of the inclusive and differential fiducial cross sections of the Higgs boson are presented, using the τ lepton decay channel. The differential cross sections are measured as functions of the Higgs boson transverse momentum, jet multiplicity, and transverse momentum of the leading jet in the event, if any. The analysis is performed using proton-proton collision data collected with the CMS detector at the LHC at a center-of-mass energy of 13  TeV and corresponding to an integrated luminosity of 138  fb^{-1}. These are the first differential measurements of the Higgs boson cross section in the final state of two τ leptons. In final states with a large jet multiplicity or with a Lorentz-boosted Higgs boson, these measurements constitute a significant improvement over measurements performed in other final states.

Search for long-lived particles decaying to leptons with large impact parameter in proton-proton collisions at s = 13 Te

A search for new long-lived particles decaying to leptons using proton-proton collision data produced by the CERN LHC at s = 13 Te is presented. Events are selected with two leptons (an electron and a muon, two electrons, or two muons) that both have transverse impact parameter values between 0.01 and 10 cm and are not required to form a common vertex. Data used for the analysis were collected with the CMS detector in 2016, 2017, and 2018, and correspond to an integrated luminosity of 118 (113) fb - 1 in the e e channel ( e μ and μ μ channels). The search is designed to be sensitive to a wide range of models with displaced e μ , e e , and μ μ final states. The results constrain several well-motivated models involving new long-lived particles that decay to displaced leptons. For some areas of the available phase space, these are the most stringent constraints to date.

Search for Long-Lived Particles Decaying in the CMS End Cap Muon Detectors in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for long-lived particles (LLPs) produced in decays of standard model (SM) Higgs bosons is presented. The data sample consists of 137  fb^{-1} of proton-proton collisions at sqrt[s]=13  TeV, recorded at the LHC in 2016-2018. A novel technique is employed to reconstruct decays of LLPs in the end cap muon detectors. The search is sensitive to a broad range of LLP decay modes and to masses as low as a few GeV. No excess of events above the SM background is observed. The most stringent limits to date on the branching fraction of the Higgs boson to LLPs subsequently decaying to quarks and τ^{+}τ^{-} are found for proper decay lengths greater than 6, 20, and 40 m, for LLP masses of 7, 15, and 40 GeV, respectively.

Measurements of the Electroweak Diboson Production Cross Sections in Proton-Proton Collisions at sqrt[s]=5.02 TeV Using Leptonic Decays

The first measurements of diboson production cross sections in proton-proton interactions at a center-of-mass energy of 5.02 TeV are reported. They are based on data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 302  pb^{-1}. Events with two, three, or four charged light leptons (electrons or muons) in the final state are analyzed. The WW, WZ, and ZZ total cross sections are measured as σ_{WW}=37.0_{-5.2}^{+5.5}(stat)_{-2.6}^{+2.7}(syst)  pb, σ_{WZ}=6.4_{-2.1}^{+2.5}(stat)_{-0.3}^{+0.5}(syst)  pb, and σ_{ZZ}=5.3_{-2.1}^{+2.5}(stat)_{-0.4}^{+0.5}(syst)  pb. All measurements are in good agreement with theoretical calculations at combined next-to-next-to-leading order quantum chromodynamics and next-to-leading order electroweak accuracy.