We report on the expected sensitivity of dedicated scintillator-based detectors at the LHC for elementary particles with charges much smaller than the electron charge. The dataset provided by a ...prototype scintillator-based detector is used to characterize the performance of the detector and provide an accurate background projection. Detector designs, including a novel slab detector configuration, are considered for the data taking period of the LHC to start in 2022 (Run 3) and for the high luminosity LHC. With the Run 3 dataset, the existence of new particles with masses between 10 MeV and 45 GeV could be excluded at 95% confidence level for charges between 0.003 e and 0.3 e, depending on their mass. With the high luminosity LHC dataset, the expected limits would reach between 10 MeV and 80 GeV for charges between 0.0018 e and 0.3 e, depending on their mass.
Foodborne illnesses caused by Escherichia coli are one of the most important gastrointestinal diseases and therefore represent a public health risk. The presence of E. coli in water or in products ...such as shrimp indicates faecal contamination. However, indicator micro‐organisms can be used to evaluate the microbiological quality of food sold in markets. This study focused on detecting isolates of E. coli containing the genes stx1A, stx2A, eae, LTI, STa, STb, aggR and pCVD432 in chilled shrimp sold in street markets in the municipality of São Paulo, Brazil, and to assess the microbiological quality of this product. Enteropathogenic and enterotoxigenic E. coli pathotypes were detected on the surface of two chilled shrimp samples. Salmonella spp. was not isolated. In addition, contamination of surface and muscle of the shrimp samples was found to be correlated. The detection of EPEC and ETEC pathotypes in chilled shrimp sold in street markets in Brazil provides useful epidemiological information for public health authorities to improve food safety and public health.
Significance and Impact of the Study
Shrimps are crustaceans commonly produced and consumed in Brazil. Specimens of Farfantepenaeus brasiliensis and Litopenaeus schmitti sold in street markets were examined by PCR to detect the presence of Escherichia coli pathotypes (enteropathogenic, enterotoxigenic, enterohemorrhagic and enteroinvasive). EPEC and ETEC strains were detected in whole shrimp. These findings provide useful information for public health authorities to improve the food safety and health of the Brazilian population.
Significance and Impact of the Study: Shrimps are crustaceans commonly produced and consumed in Brazil. Specimens of Farfantepenaeus brasiliensis and Litopenaeus schmitti sold in street markets were examined by PCR to detect the presence of Escherichia coli pathotypes (enteropathogenic, enterotoxigenic, enterohemorrhagic and enteroinvasive). EPEC and ETEC strains were detected in whole shrimp. These findings provide useful information for public health authorities to improve the food safety and health of the Brazilian population.
We report on a search for elementary particles with charges much smaller than the electron charge using a data sample of proton-proton collisions provided by the CERN Large Hadron Collider in 2018, ...corresponding to an integrated luminosity of 37.5 fb−1 at a center-of-mass energy of 13 TeV. A prototype scintillator-based detector is deployed to conduct the first search at a hadron collider sensitive to particles with charges ≤ 0.1 e . The existence of new particles with masses between 20 and 4700 MeV is excluded at 95% confidence level for charges between 0.006 e and 0.3 e , depending on their mass. New sensitivity is achieved for masses larger than 700 MeV.
The Interagency Fuels Treatment Decision Support System (IFTDSS) is a web-based software and data integration framework that organizes fire and fuels software applications into a single online ...application. IFTDSS is designed to make fuels treatment planning and analysis more efficient and effective. In IFTDSS, users can simulate fire behavior and fire effects using the scientific algorithms and processes found in desktop applications including FlamMap, Behave, FOFEM, and Consume. Strategic-level goals of IF-TDSS are to
simplify the fuels treatment planning decision-support process
improve the overall quality of analysis and planning
control long-term costs
encourage scientific collaboration
reduce agency information technology (IT) workload in-deploying and maintaining fuels applications and data; and
promote interagency collaboration within the fire and fuels community.
This paper discusses the tools and processes IFTDSS offers to fire, fuels, and resource managers responsible for planning fuels treatment within a framework of hazard analysis and risk assessment. We outline how fire and fuels treatment planners can use IFTDSS to identify areas of high hazard and risk, evaluate the potential burning risk and hazard level for valued resources (values at risk) within the area of interest, and simulate the effectiveness of fuels treatments in reducing the potential harm to values at risk.
A search is presented for new Higgs bosons in proton-proton (pp) collision events in which a same-sign top quark pair is produced in association with a jet, via the pp→tH/A→ttc‾ and pp→tH/A→ttu‾ ...processes. Here, H and A represent the extra scalar and pseudoscalar boson, respectively, of the second Higgs doublet in the generalized two-Higgs-doublet model (g2HDM). The search is based on pp collision data collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 138fb−1. Final states with a same-sign lepton pair in association with jets and missing transverse momentum are considered. New Higgs bosons in the 200–1000 GeV mass range and new Yukawa couplings between 0.1 and 1.0 are targeted in the search, for scenarios in which either H or A appear alone, or in which they coexist and interfere. No significant excess above the standard model prediction is observed. Exclusion limits are derived in the context of the g2HDM.
A search for an exotic decay of the Higgs boson to a Z boson and a light pseudoscalar particle (a), decaying to a pair of leptons and a pair of photons, respectively, is presented. The search is ...based on proton-proton collision data at a center-of-mass energy of s=13TeV, collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 138fb−1. The analysis probes pseudoscalar masses ma between 1 and 30 GeV, leading to two pairs of well-isolated leptons and photons. Upper limits at 95% confidence level are set on the Higgs boson production cross section times its branching fraction to two leptons and two photons. The observed (expected) limits are in the range of 1.1–17.8 (1.7–17.9)fb within the probed ma interval. An excess of data above the expected standard model background with a local (global) significance of 2.6 (1.3) standard deviations is observed for a mass hypothesis of ma=3GeV. Limits on models involving axion-like particles, formulated as an effective field theory, are also reported.
Abstract A search for exotic decays of the Higgs boson ( $$\text {H}$$ H ) with a mass of 125 $$\,\text {Ge}\hspace{-.08em}\text {V}$$ Ge V to a pair of light pseudoscalars $$\text {a}_{1} $$ a 1 is ...performed in final states where one pseudoscalar decays to two $${\textrm{b}}$$ b quarks and the other to a pair of muons or $$\tau $$ τ leptons. A data sample of proton–proton collisions at $$\sqrt{s}=13\,\text {Te}\hspace{-.08em}\text {V} $$ s = 13 Te V corresponding to an integrated luminosity of 138 $$\,\text {fb}^{-1}$$ fb - 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 ( $$\text {CL}$$ CL ) on the Higgs boson branching fraction to $$\upmu \upmu \text{ b } \text{ b } $$ μ μ b b and to $$\uptau \uptau \text{ b } \text{ b },$$ τ τ b b , via a pair of $$\text {a}_{1} $$ a 1 s. The limits depend on the pseudoscalar mass $$m_{\text {a}_{1}}$$ m a 1 and are observed to be in the range (0.17–3.3) $$\times 10^{-4}$$ × 10 - 4 and (1.7–7.7) $$\times 10^{-2}$$ × 10 - 2 in the $$\upmu \upmu \text{ b } \text{ b } $$ μ μ b b and $$\uptau \uptau \text{ b } \text{ b } $$ 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 $${\mathcal {B}}(\text {H} \rightarrow \text {a}_{1} \text {a}_{1} \rightarrow \ell \ell \text{ b } \text{ b})$$ B ( H → a 1 a 1 → ℓ ℓ b b ) at 95% $$\text {CL}$$ CL , with $$\ell $$ ℓ being a muon or a $$\uptau $$ τ lepton. For different types of 2HDM+S, upper bounds on the branching fraction $${\mathcal {B}}(\text {H} \rightarrow \text {a}_{1} \text {a}_{1} )$$ 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, $${\mathcal {B}}(\text {H} \rightarrow \text {a}_{1} \text {a}_{1} )$$ B ( H → a 1 a 1 ) values above 0.23 are excluded at 95% $$\text {CL}$$ CL for $$m_{\text {a}_{1}}$$ m a 1 values between 15 and 60 $$\,\text {Ge}\hspace{-.08em}\text {V}$$ Ge V .
Abstract Measurements of inclusive and normalized differential cross sections of the associated production of top quark-antiquark and bottom quark-antiquark pairs, t t ¯ b b ¯ $$ ...\textrm{t}\overline{\textrm{t}}\textrm{b}\overline{\textrm{b}} $$ , are presented. The results are based on data from proton-proton collisions collected by the CMS detector at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb −1. The cross sections are measured in the lepton+jets decay channel of the top quark pair, using events containing exactly one isolated electron or muon and at least five jets. Measurements are made in four fiducial phase space regions, targeting different aspects of the t t ¯ b b ¯ $$ \textrm{t}\overline{\textrm{t}}\textrm{b}\overline{\textrm{b}} $$ process. Distributions are unfolded to the particle level through maximum likelihood fits, and compared with predictions from several event generators. The inclusive cross section measurements of this process in the fiducial phase space regions are the most precise to date. In most cases, the measured inclusive cross sections exceed the predictions with the chosen generator settings. The only exception is when using a particular choice of dynamic renormalization scale, μ R = 1 2 ∏ i = t , t ¯ , b , b ¯ m T , i 1 / 4 $$ {\mu}_{\textrm{R}}=\frac{1}{2}{\prod}_{i=\textrm{t},\overline{\textrm{t}},\textrm{b},\overline{\textrm{b}}}{m}_{\textrm{T},i}^{1/4} $$ , where m T , i 2 = m i 2 + p T , i 2 $$ {m}_{\textrm{T},i}^2={m}_i^2+{p}_{\textrm{T},i}^2 $$ are the transverse masses of top and bottom quarks. The differential cross sections show varying degrees of compatibility with the theoretical predictions, and none of the tested generators with the chosen settings simultaneously describe all the measured distributions.
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