Análisis filogenético preliminar de la familia Richardiidae (Diptera:Teprhitoidea)

Se analizó la filogenia de 23 géneros de Richardiidae, utilizando caracteres morfológicos. La subfamilia Epiplatinae mostró una mayor retención de estados plesiomórficos y mayor consistencia en los estados de los caracteres. Esta subfamilia se caracterizó principalmente por poseer una frente pilosa; presencia de un 3r. segmento antenal oblongo: una corta distancia entre el ocellus anterior y los posteriores; setas acrosticales y dorsocentrales presuturales presentes; vena Sc con setas; patas sin espinas; tergitos abdominales 1 y II separados, ademas de otros caracteres. Por su parte los Richardiinae mostraron una mayor heterogenidad en los géneros que la conforman, lo cual permitió la segregación en tres nuevas tribus Odontomerini, Richardini, y Setellini

Primer reporte de Ornithonyssus bursa (Berlese, 1888) (Acari: Mesostigmata: Macronyssidae) en República Dominicana

Se reporta por primera vez para República Dominicana el ácaro Ornithonyssus bursa (Berlese) (Acari: Mesostigmata: Macronyssidae) y un caso de dermatitis provocado por este ácaro a humanos. El caso estuvo relacionado a una infestación de ácaros originada en nidos de Passer domesticus L. Se sospecha que casos como este podrían estar ocurriendo con más frecuencia y ser confundidos con alergias

Memorias del Séptimo Foro de la Enseñanza de las Matemáticas

En el Séptimo Foro de Enseñanza de las Matemática Ibero 2017 se abordaron temas relacionados con el uso de la historia de las matemáticas en el aula, las transformaciones en las habilidades, destrezas y conocimientos en los alumnos universitarios en la primera década del 2000, el uso de plataformas digitales en la enseñanza de las matemáticas; se expuso sobre situaciones problema en la vida cotidiana relacionados con las matemáticas escolares y la modelación matemática, sobre la historia de la enseñanza de las matermáticas, entre otros temas.ITESO, A.C.Universidad Iberoamericana, Campus Santa F

Development and validation of HERWIG 7 tunes from CMS underlying-event measurements

This paper presents new sets of parameters (“tunes”) for the underlying-event model of the HERWIG7 event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in HERWIG7, and are obtained from a fit to minimum-bias data collected by the CMS experiment at s=0.9, 7, and 13Te. The tunes are based on the NNPDF 3.1 next-to-next-to-leading-order parton distribution function (PDF) set for the parton shower, and either a leading-order or next-to-next-to-leading-order PDF set for the simulation of MPI and the beam remnants. Predictions utilizing the tunes are produced for event shape observables in electron-positron collisions, and for minimum-bias, inclusive jet, top quark pair, and Z and W boson events in proton-proton collisions, and are compared with data. Each of the new tunes describes the data at a reasonable level, and the tunes using a leading-order PDF for the simulation of MPI provide the best description of the dat

An embedding technique to determine ττ backgrounds in proton-proton collision data

An embedding technique is presented to estimate standard model tau tau backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed mu mu events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the production of associated jets in the simulation are avoided. The technique described in this paper was developed for CMS. Its validation and the inherent uncertainties are also discussed. The demonstration of the performance of the technique is based on a sample of proton-proton collisions collected by CMS in 2017 at root s = 13 TeV corresponding to an integrated luminosity of 41.5 fb(-1).Peer reviewe

Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions

Peer reviewe

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV