5,995 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
Irreducible actions and compressible modules
Any finite set of linear operators on an algebra yields an operator
algebra and a module structure on A, whose endomorphism ring is isomorphic
to a subring of certain invariant elements of . We show that if is
a critically compressible left -module, then the dimension of its
self-injective hull over the ring of fractions of is bounded by the
uniform dimension of and the number of linear operators generating .
This extends a known result on irreducible Hopf actions and applies in
particular to weak Hopf action. Furthermore we prove necessary and sufficient
conditions for an algebra A to be critically compressible in the case of group
actions, group gradings and Lie actions
Evaluation of six nopal (Opuntia spp.) varieties for fodder production in the semi-arid Northeast, Brazil.
The main problems associated with production of fodder nopal in the Sertão region, Semi-arid Northeast, Brazil, are poor soils, high minimum temperature (above 20.5o C), and the armored scale insect (Diaspis echinocacti - Bouchè). A field trial was established in Petrolina, State of Pernambuco ( average rainfall 552.2 mm, 80% available from December to April) in April 2000. Six varieties were tested: three local varieties, ?Gigante?, the most cultivated, ?Redonda? (both Opuntia ficus-indica) and ?Doce? (Nopalea cochenillifera); the Clone IPA-20, furnished by IPA, a local research institution; two varieties provided by the Universidad. Autonoma de Chapingo, Mexico, COPENA F1 and COPENA V1. The experimental design was a CRB , with three replications. The plots had 16 m2 (four rows with eight plants/row) planting density was 20.000, plants/ha, for evaluation, only six plants of each central line were considered Manure was applied on biannual basis, at the rate of 2.86 kg/m. Weeding was performed manually. After four years (May 2004), the first harvest was done, collecting all fresh material except the basal cladode and the first layer of pads.. Annual fresh matter (FM) production was calculated dividing total yield by four. Mean production was 65.36 ± 22.99 ton FM/ha/year (CV = 35.17%). Varieties yields were: ?Gigante? nopal, 103.80 ton; ?Redonda? nopal, 78.04 ton; COPENA F1, 77.54 ton; Clone IPA-20, 74.15 ton; COPENA V1, 34.19 ton; ?Doce? nopal, 24.40 ton. ?Gigante? nopal was significantly superior (P<0.05) to the two last varieties, and ?Doce? nopal was inferior to all varieties. Height, longitudinal and transversal canopy diameters were, respectively: ?Gigante? nopal, 1.54, 1.09 and 1.08 m; ?Redonda? nopal, 1.07, 1.07 and 0.98 m; COPENA F1, 1.73, 1.08 and 0.90 m; Clone IPA-20, 1.38, 1.11 and 0.99 m; COPENA V1, 1.28, 0.91, 0.76 m; ?Doce? nopal, 1.06, 1.07, and 0.99 m. Other data that, such as, protein and fiber levels, might indicate that highest production does not assure the best variety for the region. COPENA F1 having shorter canopy diameter, in comparison to ?Gigante? nopal (0.90 vs. 1.08 m) would make it more
Opuntia as fodder in the semi-arid Northeast of Brazil.
Characterization of livestock production systems; nutritive value studies; comparison with other forages; comparison among cultivars; storage effect; final considerations.bitstream/item/196673/1/OPUNTIA-AS-FODDER-IN....pd
Sistema de Controle da Pesca de Mato Grosso do Sul SCPESCA/MS 15 - 2008.
Neste boletim encontram-se as informações sobre a pesca profissional e esportiva coletadas pelo Sistema de Controle da Pesca de Mato Grosso do Sul (SCPESCA/MS) no ano de 2008. Os dados obtidos sĂŁo provenientes do pescado capturado em toda a Bacia do Alto Paraguai em Mato Grosso do Sul e vistoriado pela PolĂcia Militar Ambiental/MS.bitstream/item/54560/1/BP107.pd
Deep shower interpretation of the cosmic ray events observed in excess of the Greisen-Zatsepin-Kuzmin energy
We consider the possibility that the ultra-high-energy cosmic ray flux has a
small component of exotic particles which create showers much deeper in the
atmosphere than ordinary hadronic primaries. It is shown that applying the
conventional AGASA/HiRes/Auger data analysis procedures to such exotic events
results in large systematic biases in the energy spectrum measurement. SubGZK
exotic showers may be mis-reconstructed with much higher energies and mimick
superGZK events. Alternatively, superGZK exotic showers may elude detection by
conventional fluorescence analysis techniques.Comment: 22 pages, 5 figure
Sistema de Controle da Pesca de Mato Grosso do Sul SCPESCA/MS 16 - 2009.
Neste boletim encontram-se as informações sobre a pesca profissional e esportiva coletadas e analisadas pelo Sistema de Controle da Pesca de Mato Grosso do Sul (SCPESCA/MS) no ano de 2009. Os dados obtidos sĂŁo provenientes do pescado capturado em toda a Bacia do Alto Paraguai em Mato Grosso do Sul e vistoriado pela PolĂcia Militar Ambiental/MS.bitstream/item/54570/1/BP108.pd
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