1,399 research outputs found
Analysing the charged scalar boson contribution to the charged-current meson anomalies
Experimental measurements collected by the BABAR, Belle, and LHCb experiments
on different observables associated with the semileptonic transition , indicate the existence of disagreement respect with the
Standard Model predictions. We analyse the charged scalar boson contributions
to these charged-current meson anomalies within the framework of two Higgs
doublet model with the most general Yukawa couplings to quarks and leptons from
the third generation, involving left-handed and right-handed (sterile)
neutrinos. We perform a phenomenological study of the Yukawa couplings
parameter space that accommodates these anomalies. We consider the most recent
data from HFLAV world-average and Belle combination, and the upper limits and . In addition, we
include in our study the prospect measurements on that the
Belle II experiment could achieve and explore, for the first time, the future
implications for the corresponding charged scalar Yukawa couplings. This
analysis updates the existing literature and includes new important
observables. Our results show that current experimental data and Belle II projection favor the interpretation of a
charged scalar boson interacting with right-handed neutrinos. Furthermore, as a
side analysis regarding the charged scalar boson interpretation, we revisit the
relation between and
by investigating whether the claim that pseudoscalar new physics
interpretations of are implausible due to the lifetime is
still valid, to the light of the recent data and Belle II prospects on
. Lastly, we reexamine addressing the anomalies in
the context of the 2HDM of Type II.Comment: 20 pages, 5 figures (14 plots), 7 Tables. V3: typos corrected,
discussion improve
Extra gauge bosons and lepton flavor universality violation in and meson decays
Lepton flavor universality can be tested through the ratio of semileptonic
meson decays and leptonic meson decays, with (). For the charged-current transitions , discrepancies between the experiment and the Standard
Model (SM) have been observed in recent years by different flavor facilities as
BABAR, Belle, and LHCb. While for the neutral-current transitions , the BABAR experiment reported recently a new measurement
of leptonic decay ratio , showing an agreement with
the SM at the level. In light of this new BABAR result and
regarding the connection between new physics (NP) interpretations to the
charged-current anomalies and neutral-current
processes, in this study, we revisit the NP
consequences of this measurement within a simplified model with extra massive
gauge bosons that coupled predominantly to left-handed leptons of the
third-generation. We show that the BABAR measurement of
cannot be easily accommodated (within its experimental range)
together with the other data, hinting towards a new
anomalous observable.Comment: 8 pages, 3 figures. v2: Discussion improved, references adde
Singlet vector leptoquark model facing recent LHCb and BABAR measurements
Muy recientemente el experimento LHCb publicó la primera medida de la relación R(Λc) = BR(Λb → Λcτν¯τ )/BR(Λb → Λcµν¯µ). Además, el experimento BABAR comunicó un nuevo resultado de la relación de desintegración leptónica del mesón Upsilon Υ(3S), a saber, RΥ(3S) = BR(Υ(3S) → τ +τ -)/BR(Υ(3S) → µ +µ -).
Ambas medidas están por debajo de sus correspondientes predicciones del Modelo Estándar (déficit), desviándose en ∼ 1,1σ y ∼ 1,8σ, respectivamente. Además, el LHCb ha presentado recientemente la primera búsqueda de la desintegración B 0 → K∗0µ ±τ ∓. Motivados por estos nuevos datos, en este trabajo se estudiamos su impacto en la fenomenología del modelo de leptoquark vectorial singlete (U1) abordando los indicios de violación de la universalidad del sabor leptónico en las desintegraciones semileptónicas de los mesones B (anomalías del mesón B anomalies), llevando a cabo un análisis de ajuste global. En general, encontramos que una versión mínima de del modelo U1 con una masa de 1.8 TeV puede explicar con éxito las anomalías del mesón B, siendo al mismo tiempo compatible con el resto de observables de sabor y con los límites del LHC. Curiosamente, nuestro estudio muestra que los nuevos observables R(Λc) y RΥ(3S) generan una fuerte tensión, dando lugar a efectos no triviales en el ajuste global. ajuste global. Futuras mejoras en los experimentos LHCb y Belle II ayudarían a comprender su complementariedad. Además, también analizamos el impacto de la sensibilidad esperada en los observables de sabor en Belle II para proporcionar una prueba adicional del modelo U1. Por último, estudiamos los supuestos mínimos
supuestos mínimos bajo los cuales el modelo U1 podría, además, proporcionar una explicación combinada del momento magnético anómalo del muón
Effect of extreme El Niño events on the precipitation of Ecuador
Extreme El Niño events stand out not only because they have powerful impacts but also because they are significantly different from other El Niños. In Ecuador, such events are accountable for
negatively impacting the economy, infrastructure, and population. Spatial–temporal
dynamics of precipitation anomalies from various types of extreme El
Niño events are analyzed and compared. Results show that for eastern Pacific (EP) and coastal Pacific (COA) El Niño types, most precipitation extremes occur in the first half of the second year of the event. Any significant difference
between events becomes more evident at this stage. Spatially, for any event, 50 % of all extreme anomalies occurred at elevations < 150 m. The difference between events was significant when considering the altitude when reaching 80 % of all extreme anomalies: the eastern Pacific (EP) El Niño from 1997/98 (EP98) at 500 m, the El Niño from January to April 2017 (COA17) at 800 m, and the EP El
Niño from 1982/83 (EP83) at 1000 m. Nevertheless, in some sectors of the Andean Cordillera, the El Niño–Southern
Oscillation (ENSO) signal could be detected at 3200–3900 m. The distance to the coastline and the
steepness of relief may play a determining role. At lowlands, anomalies are
most severe in regions where the seasonality index is the highest. These results
are useful at different decision-making levels for identifying the most
appropriate practices reducing vulnerability from a potential increase in
extreme El Niño frequency and intensity.</p
Biodiversity Assessment and Geographical Affinities of Discards in Clam Fisheries in the Atlantic–Mediterranean Transition (Northern Alboran Sea)
This study focused on the assessment and quantification of discards generated by clam fisheries along the northern Alboran Sea (western Mediterranean). Discard samples (n = 278) were collected throughout one year on board nine commercial vessels. A total of 129 species were identified, mostly represented by molluscs (72 spp.), arthropods (20 spp.) and echinoderms (12 spp.). Molluscs dominated in terms of abundance (67.5%) and biomass (94.2%). The superfamily Paguroidea (i.e. hermit crabs), together with undersized target individuals, were the most abundant taxa. The abundance and biomass of discards displayed significant maximum values in winter, which could be partly related to biotic factors including population dynamics of some dominant species. Multivariate analyses indicated the presence of different assemblages related to the targeted bivalve species, reflecting the transition between a fine surface-sands biocoenosis exposed to wave action and a well-sorted fine sands biocoenosis below 5 m depth. Analysis of biogeographical affinities showed that most discarded species (73.2%) have an extensive Atlantic range, whereas 7.1% have a restricted distribution within the Mediterranean. The presence of subtropical species highlights the uniqueness of this area (the Atlantic–Mediterranean transition) in European seas. The usefulness of discard analysis for biodiversity assessment is discussed.Postprin
Management of soft-tissue coverage of open tibia fractures in Latin America:Techniques, timing, and resources
Genetic, environmental and stochastic factors in monozygotic twin discordance with a focus on epigenetic differences
PMCID: PMC3566971This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector
A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13 TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139 fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV
Spare PRELI Gene Loci: Failsafe Chromosome Insurance?
LEA (late embryogenesis abundant) proteins encode conserved N-terminal mitochondrial signal domains and C-terminal (A/TAEKAK) motif repeats, long-presumed to confer cell resistance to stress and death cues. This prompted the hypothesis that LEA proteins are central to mitochondria mechanisms that connect bioenergetics with cell responses to stress and death signaling. In support of this hypothesis, recent studies have demonstrated that mammalian LEA protein PRELI can act as a biochemical hub, which upholds mitochondria energy metabolism, while concomitantly promoting B cell resistance to stress and induced death. Hence, it is important to define in vivo the physiological relevance of PRELI expression.Given the ubiquitous PRELI expression during mouse development, embryo lethality could be anticipated. Thus, conditional gene targeting was engineered by insertion of flanking loxP (flox)/Cre recognition sites on PRELI chromosome 13 (Chr 13) locus to abort its expression in a tissue-specific manner. After obtaining mouse lines with homozygous PRELI floxed alleles (PRELI(f/f)), the animals were crossed with CD19-driven Cre-recombinase transgenic mice to investigate whether PRELI inactivation could affect B-lymphocyte physiology and survival. Mice with homozygous B cell-specific PRELI deletion (CD19-Cre/Chr13 PRELI(-/-)) bred normally and did not show any signs of morbidity. Histopathology and flow cytometry analyses revealed that cell lineage identity, morphology, and viability were indistinguishable between wild type CD19-Cre/Chr13 PRELI(+/+) and CD19-Cre/Chr13 PRELI(-/-) deficient mice. Furthermore, B cell PRELI gene expression seemed unaffected by Chr13 PRELI gene targeting. However, identification of additional PRELI loci in mouse Chr1 and Chr5 provided an explanation for the paradox between LEA-dependent cytoprotection and the seemingly futile consequences of Chr 13 PRELI gene inactivation. Importantly, PRELI expression from spare gene loci appeared ample to surmount Chr 13 PRELI gene deficiency.These findings suggest that PRELI is a vital LEA B cell protein with failsafe genetics
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