111 research outputs found
CP asymmetry from hadronic charm rescattering in B± → π−π+π± decays at the high mass region
A model for the decay amplitude is proposed to
study the large CP violation observed at the high mass region of the Dalitz
plane. A short distance amplitude with the weak phase is
considered together with the contribution of a hadronic charm loop and a s-wave
rescattering. In the model, the appears as a
narrow resonant state of the system below threshold. It is introduced
in an unitary two channel S-matrix model of the coupled and
channels, where the complex pole in channel shows its
signature in the off-diagonal matrix element and in the associated transition amplitude. The strong phase of the resulting decay amplitude
has a sharp sign change at the threshold, changing the sign of the CP
asymmetry, as it is observed in the data. We conclude that the hadronic charm
loop and rescattering mechanism are relevant to the broadening of the CP
asymmetry around the resonance in the channel. This novel
mechanism provides a possible interpretation of the CP asymmetry defier
experimental result presented by the LHCb collaboration for the decay in the high mass region
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Ecosystem services values at risk in the Atlantic coastal zone due to sea-level rise and socioeconomic development
Uncertainties about the future extent of sea-level rise (SLR) and socioeconomic development will determine the future of coastal ecosystem services and values. This study analyzes the joint impact of flooding and socioeconomic development on the future ecosystem services and values in the Atlantic coastal zone by 2100. To this end, flood probability maps (using the Uncertainty Bathtub Model; uBTM) and local ecosystem service value (ESV) estimates (using meta-analytic based global ecosystem service value functions for Provisioning, Regulating & maintenance, and Cultural ecosystem services across 12 biomes) are derived for a wide combination of Representative Concentration Pathway (RCP) and Shared Socioeconomic Pathways (SSP) scenarios to obtain future values of coastal ecosystem services (ES). Results show that the higher potential of ESV at risk is associated with RCP 8.5 and SSP5, i.e. the scenario associated with a narrative related to fossil-fueled development. For this scenario, by 2100, the coastal zone with the highest probable losses in Provisioning ESV is Europe (∼5.9 € billion/year), for Regulating & maintenance ESV this is North America (∼6.0 € billion/year) and for Cultural ESV this is South America (∼21.3 € billion/year). Countries facing highest relative risk of losing Provisioning ESV are the Netherlands (10.6 %), United States (7.4 %), and Mauritania (5.8 %). For Regulating & maintenance ESV, the top 3 countries impacted are Mauritania (17.6 %), the Netherlands (10.0 %) and Argentina (8.0 %). For Cultural ESV, the countries are Mexico (19.0 %), Denmark (18.1 %) and Sweden (15.6 %). Changes in ESV are exponentially related to flood risk and economic growth, such that small changes in flood or income lead to large changes in ESV. Unlike previous studies, the ESV functions used are dependent on time and local factors, such as population and income. Although population and income growth result in an increase in ESV, it also emphasizes the ecosystem service values at risk. Thus, sea-level rise and socioeconomic changes impact ecosystem services and values – directly affecting the well-being of the world population. The unequal distribution of coastal ecosystem service value losses across continents and countries highlighted in this work is important to identify what values are at risk and for whom. Adaptation measures and strategies can, in turn, be defined
Root system traits and its relationship with photosynthesis and productivity in four maize genotypes under drought
The present study combined evaluations of agronomic parameters such as roots morphometry (using the WinRhizo program) and leaf gas exchange, in order to detect features in the root system which allow the maintenance of photosynthetic rates and productivity in four maize genotypes contrasting for tolerance to water deficit (WD), two tolerant (DKB 390 and BRS1055) and two sensitive (BRS 1010 and 2B710). The genotypes showed similar tolerance to dehydration of leaf tissue, but the tolerant genotypes DKB 390 and BRS1055 presented higher photosynthetic rate and yield compared to the sensitive BRS 1010 and 2B710. Nevertheless, divergent strategies of adaptation to drought among tolerant genotypes were observed. The genotype DKB 390 presented physiological mechanisms in shoots responsible for minimizing water loss, which decreases the dependence of root adjustments to increase the absorption of water. In turn, the BRS 1055 genotype showed a drought avoidance strategy by producing fine roots associated with a higher leaf area
Produtividade de raízes de mandioca consorciada com milho e caupi em sistema orgânico.
Foram avaliados sistemas orgânicos de produção de mandioca “de mesa”, em Seropédica (RJ). O experimento constou dos seguintes tratamentos: monocultivo de mandioca (cv. IAC 576-70) e consórcios com milho experimental (cv. Eldorado), caupi (cv. Mauá) e milho+caupi. O manejo orgânico foi padronizado e toda a área experimental irrigada durante o período de permanência do milho no sistema. Do milho, foram colhidas espigas verdes (imaturas) e a parte aérea acamada na superfície do solo. O caupi foi incluído como adubo verde e cortado na floração, sendo mantidos os resíduos na superfície do solo. Ambos os consortes ocuparam as entrelinhas da mandioca, de modo alternado, semeados após a primeira capina da cultura principal. A cultivar IAC 576-70 mostrou-se adaptada ao manejo orgânico, com produtividade de raízes de padrão comercial próxima a 31 Mg ha-¹. Não houve diferenças significativas entre o monocultivo e os três tipos de consórcios testados. A inclusão do milho representou potencial de renda adicional ao produtor, colhendo-se,em média, 18.125 espigas ha-¹, o que correspondeu a 5,1 Mg ha-¹. Os resíduos provenientes da roçada do caupi proporcionaram um aporte de biomassa fresca de 12 Mg ha-¹, com uma expressiva contribuição em nitrogênio (cerca de 44 kg de N ha-1). A fabácea leguminosa cobriu por completo as entrelinhas da mandioca,demonstrando seu potencial de controle à erosão e a ervas espontâneas. O consórcio triplo mostrou-se vantajoso tendo em vista que a receita obtida com a venda do milho verde justificaria os custos da irrigação, além dos benefícios da inclusão do caupi e da não interferência dos consortes na produtividade da mandioca
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