8,147 research outputs found
Nature of the X(5568) : a critical Laplace sum rule analysis at N2LO
We scrutinize recent QCD spectral sum rules (QSSR) results to lowest order
(LO) predicting the masses of the BK molecule and (su)\bar(bd) four-quark
states. We improve these results by adding NLO and N2LO corrections to the PT
contributions giving a more precise meaning on the b-quark mass definition used
in the analysis. We extract our optimal predictions using Laplace sum rule
(LSR) within the standard stability criteria versus the changes of the external
free parameters (\tau-sum rule variable, t_c continuum threshold and
subtraction constant \mu). The smallness of the higher order PT corrections
justifies (a posteriori) the LO order results + the uses of the ambiguous heavy
quark mass to that order. However, our predicted spectra in the range (5173\sim
5226) MeV, summarized in Table 7, for exotic hadrons built with four different
flavours (buds), do not support some previous interpretations of the D0
candidate[1], X(5568), as a pure molecule or a four-quark state. If
experimentally confirmed, it could result from their mixing with an angle: sin
2\theta\approx 0.15. One can also scan the region (2327~ 2444) MeV (where the
D*_{s0}(2317) might be a good candidate) and the one (5173~ 5226) MeV for
detecting these (cuds) and (buds) unmixed exotic hadrons (if any) via,
eventually, their radiative or \pi+hadrons decays.Comment: Version matching with the publised version : some references added
and updated, comments added, misprint corrected (51 pages, 66 figures, 7
tables
Controle integrado da podridão mole das raízes de mandioca no trópico úmido.
bitstream/item/38969/1/SP5860.pdfPublicado também on-line
Mandioca para farinha: aspectos históricos, etimológicos e morfoanatômicos.
bitstream/item/63890/1/Oriental-Doc325.pdfDisponível também on-line
Selection of cassava parents by morphological and agronomic TRAITS, and genetic divergence analysis.
Brazil has been suggested as the center of origin and domestication of cassava (Allem 1987, Olsen and Schaal 1999, 2001). In the Amazon region, cassava is mainly grown as a subsistence crop by small farmers, thanks to its ease of cultivation, cheap production and its ability to tolerate poor soils. Moreover it suffers from few serious pests and disease
Recomendações técnicas em caráter de prevenção à ocorrência da podridão mole das raízes da mandioca e da macaxeira.
bitstream/item/28219/1/ComTec188.pd
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