Antropoceno e História: orbis hypothesis na construção de uma História Ambiental latinoamericana

O artigo que segue tem por finalidade apresentar, de forma geral, algumas possibilidades e limitações da utilização do conceito de Antropoceno pela História Ambiental, destacando algumas disputas epistemológicas que ainda circundam o termo, como a definição de um marco temporal ou seu emprego transdisciplinar. E, de modo mais específico, explorar as possibilidades de uso da Orbis hypothesis, proposta de marco temporal para o Antropoceno na construção de uma História Ambiental Latinoamericana, destacando o modo como este possibilitaria a convergência interdisciplinar epistemológica de parâmetros e indicadores biofísicos de antropização ecossistêmica com os processos sócio-históricos coloniais fundantes da modernidade.El artículo que sigue pretende presentar, en general, algunas posibilidades y limitaciones del uso del concepto Antropoceno por parte de la Historia Ambiental, destacando algunas disputas epistemológicas que aún rodean al término, como la definición de un marco temporal o su uso transdisciplinario. Y, más específicamente, explorar las posibilidades de utilizar la Orbis hipothesys, propuesta como marco temporal del Antropoceno en la construcción de una Historia Ambiental Latinoamericana, destacando la forma en que permitiría la convergencia epistemológica interdisciplinaria de parámetros e indicadores biofísicos. de la antropización de los ecosistemas con los procesos sociohistóricos coloniales fundantes de la modernidad.The article that follows aims to present, in general, some possibilities and limitations of the use of the Anthropocene concept by Environmental History, highlighting some epistemological disputes that still surround the term, such as the definition of a timeframe or its transdisciplinary use. And, more specifically, to explore the possibilities of using the Orbis hypothesis, proposed as a timeframe for the Anthropocene in the construction of a Latin American Environmental History, highlighting the way in which it would enable the interdisciplinary epistemological convergence of biophysical parameters and indicators of ecosystem anthropization with the founding colonial socio-historical processes of modernity

TECNOLOGIA SOCIAL E AGROECOLOGIA NA PARAÍBA

Agroecology brings with it the idea of ​​building agricultural practices based on the dialogue of knowledge between modern science and traditional management techniques and proposes to break with the paradigms of Conventional Agriculture. In this context, technological practices emerge that contribute to the generation of work and income, in community, participatory activities, with low economic and environmental impact, inclusive and socially mobilizing. The present work aims to analyze how agroecological producers in Paraíba have incorporated Social Technology (ST) in their systems and how TS related to sustainable practices has influenced agrarian systems and the rural environment of Paraíba, making them closer to agroecological practices and principles. Based on the documentary analysis produced by Social Technology development projects related to the rural environment and by a bibliographical research, it was verified that there is a concentration of projects in the semi-arid region, linked to the development of water technological artifacts and that, although there are several experiences and Promising projects could have their scope and impact increased if they received support and encouragement from the State through permanent public policies to promote these initiatives.La agroecología trae consigo la idea de construir prácticas agrícolas basadas en el diálogo de saberes entre la ciencia moderna y las técnicas tradicionales de manejo y propone romper con los paradigmas de la Agricultura Convencional. En este contexto emergen prácticas tecnológicas que contribuyen a la generación de trabajo y renta, en actividades comunitarias, participativas, de bajo impacto económico y ambiental, incluyentes y socialmente movilizadoras. El presente trabajo tiene como objetivo analizar cómo los productores agroecológicos de Paraíba han incorporado la Tecnología Social (CT) en sus sistemas y cómo las TS relacionadas con prácticas sostenibles han influido en los sistemas agrarios y el medio rural de Paraíba, acercándolos a las prácticas y principios agroecológicos. Con base en el análisis documental producido por los proyectos de desarrollo de Tecnología Social relacionados con el medio rural y por una investigación bibliográfica, se verificó que existe una concentración de proyectos en la región semiárida, vinculados al desarrollo de artefactos tecnológicos del agua y que, aunque existen varias experiencias y Proyectos Prometedores podrían ver incrementado su alcance e impacto si contaran con el apoyo y estímulo del Estado a través de políticas públicas permanentes para impulsar estas iniciativas.A Agroecologia traz em si a ideia de construção de práticas agrícolas fundamentadas no diálogo de saberes entre a ciência moderna e técnicas de manejo tradicionais e se propõe a romper com os paradigmas da Agricultura Convencional. Nesse contexto, surgem práticas tecnológicas que contribuem para a geração de trabalho e renda, em atividades comunitárias, participativas, de baixo impacto econômico e ambiental, inclusivas e socialmente mobilizadoras. O presente trabalho tem como objetivo analisar de que maneira produtores e produtoras agroecológicos na Paraíba tem incorporado Tecnologia Social (TS) em seus sistemas e de que modo a TS relacionada às práticas sustentáveis têm influenciado os sistemas agrários e o meio rural paraibano, tornando-os mais próximos das práticas e princípios agroecológicos. Com base na análise documental produzida por projetos de desenvolvimento de Tecnologia Social relacionadas ao ambiente rural e por uma pesquisa bibliográfica, verificou-se que há uma concentração de projetos no semiárido, ligados ao desenvolvimento de artefatos tecnológicos hídricos e que, embora existam diversas experiências e projetos promissores, poderiam ter sua capacidade de abrangência e impacto aumentados se recebessem o apoio e incentivo do Estado através de políticas públicas permanentes de fomento destas iniciativas

Observation of four top quark production in proton-proton collisions at s\sqrt{s} = 13 TeV

International audienceThe observation of the production of four top quarks in proton-proton collisions is reported, based on a data sample collected by the CMS experiment at a center-of-mass energy of 13 TeV in 2016-2018 at the CERN LHC and corresponding to an integrated luminosity of 138 fb$^{-1}$. Events with two same-sign, three, or four charged leptons (electrons and muons) and additional jets are analyzed. Compared to previous results in these channels, updated identification techniques for charged leptons and jets originating from the hadronization of b quarks, as well as a revised multivariate analysis strategy to distinguish the signal process from the main backgrounds, lead to an improved expected signal significance of 4.9 standard deviations above the background-only hypothesis. Four top quark production is observed with a significance of 5.6 standard deviations, and its cross section is measured to be 17.7$^{+3.7}_{-3.5}$ (stat) $^{+2.3}_{-1.9}$ (syst) fb, in agreement with the available standard model predictions

Observation of the rare decay of the η\eta meson to four muons

A search for the rare $\eta$$\to$$\mu^+\mu^-\mu^+\mu^-$ 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 in 2017-2018 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 \emm decay as normalization, the branching fraction $\mathcal{B}($η$\to \mu^+\mu^-\mu^+\mu^-)$ = ( 5.0 $\pm$ 0.8 (stat) $\pm$ 0.7 (syst) $\pm$ 0.7 $\mathcal{B}_{2\mu}$ ) $\times$ 10$^{-9}$ is measured, where the last term is the uncertainty in the normalization channel branching fraction. This is the first measurement of this branching fraction and is found to be in agreement with theoretical predictions

Development of the CMS detector for the CERN LHC Run 3

International audienceSince the initial data taking of the CERN LHC, the CMS experiment has undergone substantial upgrades and improvements. This paper discusses the CMS detector as it is configured for the third data-taking period of the CERN LHC, Run 3, which started in 2022. The entire silicon pixel tracking detector was replaced. A new powering system for the superconducting solenoid was installed. The electronics of the hadron calorimeter was upgraded. All the muon electronic systems were upgraded, and new muon detector stations were added, including a gas electron multiplier detector. The precision proton spectrometer was upgraded. The dedicated luminosity detectors and the beam loss monitor were refurbished. Substantial improvements to the trigger, data acquisition, software, and computing systems were also implemented, including a new hybrid CPU/GPU farm for the high-level trigger

Search for new physics in multijet events with at least one photon and large missing transverse momentum in proton-proton collisions at 13 TeV

A search for new physics in final states consisting of at least one photon, multiple jets, and large missing transverse momentum is presented, using proton-proton collision events at a center-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 137 fb$^{-1}$, recorded by the CMS experiment at the CERN LHC from 2016 to 2018. The events are divided into mutually exclusive bins characterized by the missing transverse momentum, the number of jets, the number of b-tagged jets, and jets consistent with the presence of hadronically decaying W, Z, or Higgs bosons. The observed data are found to be consistent with the prediction from standard model processes. The results are interpreted in the context of simplified models of pair production of supersymmetric particles via strong and electroweak interactions. Depending on the details of the signal models, gluinos and squarks of masses up to 2.35 and 1.43 TeV, respectively, and electroweakinos of masses up to 1.23 TeV are excluded at 95% confidence level

Luminosity determination using Z boson production at the CMS experiment

International audienceThe 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 13 TeV. 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 dataset, in small intervals of 2 pb$^{-1}$ 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

Combination of measurements of the top quark mass from data collected by the ATLAS and CMS experiments at s=7\sqrt{s}=7 and 8 TeV

International audienceA combination of fifteen top quark mass measurements performed by the ATLAS and CMS experiments at the LHC is presented. The data sets used correspond to an integrated luminosity of up to 5 and 20$^{-1}$ of proton-proton collisions at center-of-mass energies of 7 and 8 TeV, respectively. The combination includes measurements in top quark pair events that exploit both the semileptonic and hadronic decays of the top quark, and a measurement using events enriched in single top quark production via the electroweak $t$-channel. The combination accounts for the correlations between measurements and achieves an improvement in the total uncertainty of 31% relative to the most precise input measurement. The result is $m_\mathrm{t}$ = 172.52 $\pm$ 0.14 (stat) $\pm$ 0.30 (syst) GeV, with a total uncertainty of 0.33 GeV

Observation of the Ξb−\Xi^-_\mathrm{b}→\toψ\psi(2S)Ξ−\Xi^- decay and studies of the Ξb∗0\Xi_\mathrm{b}^{\ast{}0} baryon in proton-proton collisions at s\sqrt{s} = 13 TeV

International audienceThe first observation of the decay $\Xi^-_\mathrm{b}$$\to$$\psi$(2S)$\Xi^-$ and measurement of the branching ratio of $\Xi^-_\mathrm{b}$$\to$$\psi$(2S)$\Xi^-$ to $\Xi^-_\mathrm{b}$$\to$ J/$\psi$$\Xi^-$ are presented. The J/$\psi$ and $\psi$(2S) mesons are reconstructed using their dimuon decay modes. The results are based on proton-proton colliding beam data from the LHC collected by the CMS experiment at $\sqrt{s}$ = 13 TeV in 2016-2018, corresponding to an integrated luminosity of 140 fb$^{-1}$. The branching fraction ratio is measured to be $\mathcal{B}$($\Xi^-_\mathrm{b}$$\to$$\psi$(2S)$\Xi^-$)/$\mathcal{B}$($\Xi^-_\mathrm{b}$$\to$ J/$\psi$$\Xi^-$) = 0.84$^{+0.21}_{-0.19}$ (stat) $\pm$ 0.10 (syst) $\pm$ 0.02 ($\mathcal{B}$), where the last uncertainty comes from the uncertainties in the branching fractions of the charmonium states. New measurements of the $\Xi_\mathrm{b}^{\ast{}0}$ baryon mass and natural width are also presented, using the $\Xi_\mathrm{b}^-\pi^+$ final state, where the $\Xi^-_\mathrm{b}$ baryon is reconstructed through the decays J/$\psi \Xi^-$, $\psi$(2S)$\Xi^-$, J/$\psi \Lambda$K$^-$, and J/$\psi \Sigma^0$K$^-$. Finally, the fraction of the $\Xi^-_\mathrm{b}$ baryons produced from $\Xi_\mathrm{b}^{\ast{}0}$ decays is determined

Search for the decay of the Higgs boson to a pair of light pseudoscalar bosons in the final state with four bottom quarks in proton-proton collisions at s\sqrt{s} = 13 TeV

International audienceA search is presented for the decay of the 125 GeV Higgs boson (H) to a pair of new light pseudoscalar bosons (a), followed by the prompt decay of each a boson to a bottom quark-antiquark pair, H $\to$ aa $\to$$\mathrm{b\bar{b}b\bar{b}}$. The analysis is performed using a data sample of proton-proton collisions collected with the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$. To reduce the background from standard model processes, the search requires the Higgs boson to be produced in association with a leptonically decaying W or Z boson. The analysis probes the production of new light bosons in a 15 $\lt$$m_\mathrm{a}$$\lt$ 60 GeV mass range. Assuming the standard model predictions for the Higgs boson production cross sections for pp $\to$ WH and ZH, model independent upper limits at 95% confidence level are derived for the branching fraction $\mathcal{B}$(H $\to$ aa $\to$ $\mathrm{b\bar{b}b\bar{b}}$). The combined WH and ZH observed upper limit on the branching fraction ranges from 1.10 for $m_\mathrm{a} =$ 20 GeV to 0.36 for $m_\mathrm{a} =$ 60 GeV, complementing other measurements in the $\mu\mu\tau\tau$, $\tau\tau\tau\tau$ and bb$\ell\ell$ ($\ell=$ $\mu$,$\tau$) channels