ANÁLISIS DE CRECIMIENTO INICIAL DE CINCO GENOTIPOS DE BRACHIARIA EN TRÓPICO HÚMEDO

A study was conducted to evaluate the initial growth of five Bracharia varieties in the rainy season characteristic of the humid tropic prevalent in the Santo Domingo de los Tsáchilas Province, Ecuador. The evaluated genetic material were improved varieties of Bracharia brizantha (Piatá, Xaraés y Marandú), a hybrid (Mulato II) and the variety Brachiaria decumbens, considered the check because this is the more spread material in the region. The materials were randomly distributed in plastic bags and cultivated in the open to evaluate growth during the twelve weeks after seed emergency. Results indicate that the hybrid Mulato II has higher plant establishment potential (P<0.05) than B. decumbens. However, when the growth rate was evaluated, the Marandú variety was superior (P<0.05) from the beginning of the evaluation, which translates in a greater biomass gain per unit area. The rate of net assimilation (RNA) and the relative growth rate (RGR) has a declining trend in all varieties (P<0.05) through time, the hybrid Mulato II being the one which presented the lower RNA, probably due to a lower height and greater leaf area. Reported data demonstrates the importance of determining plant physiological efficiency in the environment where they are going to be cultivated to guaranty the productive efficiency of the pastures.Se condujo un estudio para evaluar el crecimiento inicial de cinco variedades de Brachiaria en la época de lluvia característica del clima tropical húmedo de la provincia de Santo Domingo de los Tásachilas, Ecuador. Los materiales genéticos evaluados fueron variedades mejoradas de Brachiaria brizantha (Piatá, Xaraés y Marandú), Brachiaria híbrido (Mulato II) y la variedad Brachiaria decumbens, considerada como testigo por ser la que prevalece en la zona en estudio. Las variedades fueron sembradas por semilla en fundas de plástico y colocadas a la intemperie para evaluar el crecimiento durante las doce semanas posteriores a la emergencia. Los resultados indican que el híbrido Mulato II tiene mayor potencial de establecimiento (P<0.05) que B. decumbens; sin embargo, cuando se estimó la tasa de crecimiento, la variedad Marandú fue superior (P<0.05) desde el inicio de la evaluación, ex presado por una mayor acumulación de biomasa por unidad de área. La tasa de asimilación neta (TAN) y la tasa relativa de crecimiento (TRC) mostraron un comportamiento descendente en todas las variedades (P>0.05) a lo largo del tiempo, siendo el hibrido Mulato II el que presentó la menor TAN, debido probablemente a la menor altura y mayor área foliar. Los resultados obtenidos demuestran la importancia de determinar la eficiencia fisiológica de las plantas forrajeras en el ambiente donde se van a cultivar, para garantizar la eficiencia durante el establecimiento de las praderas

Measurement of the Splitting Function in &ITpp &ITand Pb-Pb Collisions at root&ITsNN&IT=5.02 TeV

Data from heavy ion collisions suggest that the evolution of a parton shower is modified by interactions with the color charges in the dense partonic medium created in these collisions, but it is not known where in the shower evolution the modifications occur. The momentum ratio of the two leading partons, resolved as subjets, provides information about the parton shower evolution. This substructure observable, known as the splitting function, reflects the process of a parton splitting into two other partons and has been measured for jets with transverse momentum between 140 and 500 GeV, in pp and PbPb collisions at a center-of-mass energy of 5.02 TeV per nucleon pair. In central PbPb collisions, the splitting function indicates a more unbalanced momentum ratio, compared to peripheral PbPb and pp collisions.. The measurements are compared to various predictions from event generators and analytical calculations.Peer reviewe

Measurement of nuclear modification factors of gamma(1S)), gamma(2S), and gamma(3S) mesons in PbPb collisions at root s(NN)=5.02 TeV

The cross sections for ϒ(1S), ϒ(2S), and ϒ(3S) production in lead-lead (PbPb) and proton-proton (pp) collisions at √sNN = 5.02 TeV have been measured using the CMS detector at the LHC. The nuclear modification factors, RAA, derived from the PbPb-to-pp ratio of yields for each state, are studied as functions of meson rapidity and transverse momentum, as well as PbPb collision centrality. The yields of all three states are found to be significantly suppressed, and compatible with a sequential ordering of the suppression, RAA(ϒ(1S)) > RAA(ϒ(2S)) > RAA(ϒ(3S)). The suppression of ϒ(1S) is larger than that seen at √sNN = 2.76 TeV, although the two are compatible within uncertainties. The upper limit on the RAA of ϒ(3S) integrated over pT, rapidity and centrality is 0.096 at 95% confidence level, which is the strongest suppression observed for a quarkonium state in heavy ion collisions to date. © 2019 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP3.Peer reviewe

Electroweak production of two jets in association with a Z boson in proton-proton collisions root s =13 TeV

A measurement of the electroweak (EW) production of two jets in association with a Z boson in proton-proton collisions at root s = 13 TeV is presented, based on data recorded in 2016 by the CMS experiment at the LHC corresponding to an integrated luminosity of 35.9 fb(-1). The measurement is performed in the lljj final state with l including electrons and muons, and the jets j corresponding to the quarks produced in the hard interaction. The measured cross section in a kinematic region defined by invariant masses m(ll) > 50 GeV, m(jj) > 120 GeV, and transverse momenta P-Tj > 25 GeV is sigma(EW) (lljj) = 534 +/- 20 (stat) fb (syst) fb, in agreement with leading-order standard model predictions. The final state is also used to perform a search for anomalous trilinear gauge couplings. No evidence is found and limits on anomalous trilinear gauge couplings associated with dimension-six operators are given in the framework of an effective field theory. The corresponding 95% confidence level intervals are -2.6 <cwww/Lambda(2) <2.6 TeV-2 and -8.4 <cw/Lambda(2) <10.1 TeV-2. The additional jet activity of events in a signal-enriched region is also studied, and the measurements are in agreement with predictions.Peer reviewe

Inclusive Search for a Highly Boosted Higgs Boson Decaying to a Bottom Quark-Antiquark Pair

© 2018 CERN. An inclusive search for the standard model Higgs boson (H) produced with large transverse momentum (pT) and decaying to a bottom quark-antiquark pair (bb) is performed using a data set of pp collisions at s=13 TeV collected with the CMS experiment at the LHC. The data sample corresponds to an integrated luminosity of 35.9 fb-1. A highly Lorentz-boosted Higgs boson decaying to bb is reconstructed as a single, large radius jet, and it is identified using jet substructure and dedicated b tagging techniques. The method is validated with Z→bb decays. The Z→bb process is observed for the first time in the single-jet topology with a local significance of 5.1 standard deviations (5.8 expected). For a Higgs boson mass of 125 GeV, an excess of events above the expected background is observed (expected) with a local significance of 1.5 (0.7) standard deviations. The measured cross section times branching fraction for production via gluon fusion of H→bb with reconstructed pT > 450 GeV and in the pseudorapidity range -2.5 < η < 2.5 is 74±48(stat)-10+17(syst) fb, which is consistent within uncertainties with the standard model prediction

Search for new phenomena in final states with two opposite-charge, same-flavor leptons, jets, and missing transverse momentum in pp collisions at √s=13 TeV

Search results are presented for physics beyond the standard model in final states with two opposite-charge, same-flavor leptons, jets, and missing transverse momentum. The data sample corresponds to an integrated luminosity of 35.9 fb−1 of proton-proton collisions at s√=13 TeV collected with the CMS detector at the LHC in 2016. The analysis uses the invariant mass of the lepton pair, searching for a kinematic edge or a resonant-like excess compatible with the Z boson mass. The search for a kinematic edge targets production of particles sensitive to the strong force, while the resonance search targets both strongly and electroweakly produced new physics. The observed yields are consistent with the expectations from the standard model, and the results are interpreted in the context of simplified models of supersymmetry. In a gauge mediated supersymmetry breaking (GMSB) model of gluino pair production with decay chains including Z bosons, gluino masses up to 1500–1770 GeV are excluded at the 95% confidence level depending on the lightest neutralino mass. In a model of electroweak chargino-neutralino production, chargino masses as high as 610 GeV are excluded when the lightest neutralino is massless. In GMSB models of electroweak neutralino-neutralino production, neutralino masses up to 500-650 GeV are excluded depending on the decay mode assumed. Finally, in a model with bottom squark pair production and decay chains resulting in a kinematic edge in the dilepton invariant mass distribution, bottom squark masses up to 980–1200 GeV are excluded depending on the mass of the next-to-lightest neutralino

Thermal sum in the determination of the phenological stages of Chihuahua and Cuauhtémoc oats in Güémez Tamaulipas

Objective: To determine the thermal sum requirements in degrees days of development (GDD) of the varieties of Avena sativa, Cuauhtémoc and Chihuahua by phenological stage and its effect on the accumulation of total forage and by morphological component in Güémez, Tamaulipas. Design/methodology/approach: The sowing was carried out in plots of 6×6 m and four repetitions of the Cuauhtémoc and Chihuahua varieties through the mechanized preparation of the land, with doses of 120 kg ha-1 of seed and, subsequently, irrigation and fertilization work was carried out. The treatments were made up of the two varieties and six phenological stages (Zadoks scale: Z2, Z3, Z4, Z7, Z8, Z9) in a random complete block design. Results: It was found that, the months of November to March allow to obtain 1923.5 and 1831.5 GDD as a requirement of the crop to complete the biological cycle of the Chihuahua and Cuauhtémoc varieties. Yields by morphological component depended on the observed phenological stage and the highest leaf yield was obtained with 2.7 and 3.6 t ha-1 in Cuauhtémoc and Chihuahua, respectively (P&lt;0.05) in stage Z3, with an accumulation of 1032 and 980 GDD in the stem elongation stage. Limitations on study/implications: These results are applicable only for the evaluation area, because they are physiological responses where the environment intervenes. Findings/conclusions: In Güémez, Tamaulipas, the Chihuahua oat variety requires 1923.5 GDD to complete the biological cycle, while Cuauhtémoc 1831.5 GDD. The difference between the thermal accumulation of the varieties and the phenological stages has an impact on the total forage yield and by morphological component

Measurements of the pp -> ZZ production cross section and the Z -> 4l branching fraction, and constraints on anomalous triple gauge couplings at root s=13TeV

Correction: DOI:10.1140/epjc/s10052-018-5769-1Four-lepton production in proton-proton collisions, pp -> (Z/gamma*)(Z/gamma*) -> 4l, where l = e or mu, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 35.9 fb(-1). The ZZ production cross section, sigma(pp -> ZZ) = 17.2 +/- 0.5 (stat) +/- 0.7 (syst) +/- 0.4 (theo) +/- 0.4 (lumi) pb, measured using events with two opposite-sign, same-flavor lepton pairs produced in the mass region 60 4l) = 4.83(-0.22)(+0.23) (stat)(-0.29)(+0.32) (syst) +/- 0.08 (theo) +/- 0.12(lumi) x 10(-6) for events with a four-lepton invariant mass in the range 80 4GeV for all opposite-sign, same-flavor lepton pairs. The results agree with standard model predictions. The invariant mass distribution of the four-lepton system is used to set limits on anomalous ZZZ and ZZ. couplings at 95% confidence level: -0.0012 <f(4)(Z) <0.0010, -0.0010 <f(5)(Z) <0.0013, -0.0012 <f(4)(gamma) <0.0013, -0.0012 <f(5)(gamma) <0.0013.Peer reviewe

Search for new physics in dijet angular distributions using proton-proton collisions at root s=13 TeV and constraints on dark matter and other models

An Erratum to this article was published on 29 April 2022: https://doi.org/10.1140/epjc/s10052-022-10278-0search is presented for physics beyond the standard model, based on measurements of dijet angular distributions in proton-proton collisions at root s = 13 TeV. The data collected with the CMS detector at the LHC correspond to an integrated luminosity of 35.9 fb(-1). The observed distributions, corrected to particle level, are found to be in agreement with predictions from perturbative quantum chromodynamics that include electroweak corrections. Constraints are placed on models containing quark contact interactions, extra spatial dimensions, quantum black holes, or dark matter, using the detector-level distributions. In a benchmark model where only left-handed quarks participate, contact interactions are excluded at the 95% confidence level up to a scale of 12.8 or 17.5 TeV, for destructive or constructive interference, respectively. The most stringent lower limits to date are set on the ultraviolet cutoff in the Arkani-Hamed-Dimopoulos-Dvali model of extra dimensions. In the Giudice-Rattazzi-Wells convention, the cutoff scale is excluded up to 10.1 TeV. The production of quantum black holes is excluded for masses below 5.9 and 8.2 TeV, depending on the model. For the first time, lower limits between 2.0 and 4.6 TeV are set on the mass of a dark matter mediator for (axial-)vector mediators, for the universal quark coupling g(q) = 1.0.Peer reviewe