The BES f_0(1810): a new glueball candidate

We analyze the f_0(1810) state recently observed by the BES collaboration via radiative J/\psi decay to a resonant \phi\omega spectrum and confront it with DM2 data and glueball theory. The DM2 group only measured \omega\omega decays and reported a pseudoscalar but no scalar resonance in this mass region. A rescattering mechanism from the open flavored KKbar decay channel is considered to explain why the resonance is only seen in the flavor asymmetric \omega\phi branch along with a discussion of positive C parity charmonia decays to strengthen the case for preferred open flavor glueball decays. We also calculate the total glueball decay width to be roughly 100 MeV, in agreement with the narrow, newly found f_0, and smaller than the expected estimate of 200-400 MeV. We conclude that this discovered scalar hadron is a solid glueball candidate and deserves further experimental investigation, especially in the K-Kbar channel. Finally we comment on other, but less likely, possible assignments for this state.Comment: 11 pages, 4 figures. Major substantive additions, including an ab-initio, QCD-based computation of the glueball inclusive decay width, evaluation of final state effects, and enhanced discussion of several alternative possibilities. Our conclusions are unchanged: the BES f_0(1810) is a promising glueball candidat

Effects Of External Fields On The Far-infrared 1s→2p+ Intradonor Absorption Spectra In Quantum Wells

The effects of both electric and magnetic fields (applied perpendicular to the interfaces) on the donor transition energies on a GaAs-Ga1-xAlxAs quantum well are studied by following a variational calculation within the effective-mass approximation with two-parameter variational envelope hydrogenic wave functions for the 1s- and 2p+-like donor states. A detailed analysis of the far-infrared intradonor absorption spectra, taking into account a proper consideration of the impurity-doping profile, is performed and results are compared with recent experimental data. The agreement between the reported magnetospectroscopic data and the average photon energy at the width at half-maximum of the calculated infrared-absorption spectra is quite apparent. It is unambiguously shown that the absorption spectra must be evaluated with an adequate choice of the variational envelope wave function for a correct quantitative understanding of the experimental measurements. © 1996 American Institute of Physics.80425362538Parihar, S.R., Lyon, S.A., (1993) Appl. Phys. Lett., 62, p. 2396Jarosik, N.C., McCombe, B.D., Shanabrook, B.V., Comas, J., Ralston, J., Wicks, G., (1985) Phys. Rev. Lett., 54, p. 1283Barmby, P.W., Dunn, J.L., Bates, C.A., (1994) J. Phys. Condens. Matter, 6, p. 751. , and references thereinChen, R., Cheng, J.P., Lin, D., McCombe, B.D., George, T.F., (1995) J. Phys. Condens. Matter, 7, p. 3577. , and references thereinLatgé, A., Porras-Montenegro, N., Oliveira, L.E., (1995) Phys. Rev. B, 51, p. 2259(1995) Phys. Rev. B, 51, p. 13344Latgé, A., Porras-Montenegro, N., De Dios-Leyva, M., Oliveira, L.E., (1996) Phys. Rev. B, 53, p. 10160Barbosa, L.H.M., Latgé, A., De Dios-Leyva, M., Oliveira, L.E., (1996) Solid State Commun., 98, p. 215Yoo, B.S., McCombe, B.D., Schaff, W., (1991) Phys. Rev. B, 44, p. 13152López-Gondar, J., D'Albuquerque E Castro, J., Oliveira, L.E., (1990) Phys. Rev. B, 42, p. 7069Greene, R.L., Bajaj, K.K., (1985) Phys. Rev. B, 31, p. 913(1986) Phys. Rev. B, 34, p. 951(1988) Phys. Rev. B, 37, p. 4604Chaudhuri, S., Bajaj, K.K., (1984) Solid State Commun., 52, p. 967(1984) Phys. Rev. B, 29, p. 1803Greene, R.L., Lane, P., (1986) Phys. Rev. B, 34, p. 8639(1986) Phys. Rev. B, 33, p. 587

Cerulean: A hybrid assembly using high throughput short and long reads

Genome assembly using high throughput data with short reads, arguably, remains an unresolvable task in repetitive genomes, since when the length of a repeat exceeds the read length, it becomes difficult to unambiguously connect the flanking regions. The emergence of third generation sequencing (Pacific Biosciences) with long reads enables the opportunity to resolve complicated repeats that could not be resolved by the short read data. However, these long reads have high error rate and it is an uphill task to assemble the genome without using additional high quality short reads. Recently, Koren et al. 2012 proposed an approach to use high quality short reads data to correct these long reads and, thus, make the assembly from long reads possible. However, due to the large size of both dataset (short and long reads), error-correction of these long reads requires excessively high computational resources, even on small bacterial genomes. In this work, instead of error correction of long reads, we first assemble the short reads and later map these long reads on the assembly graph to resolve repeats. Contribution: We present a hybrid assembly approach that is both computationally effective and produces high quality assemblies. Our algorithm first operates with a simplified version of the assembly graph consisting only of long contigs and gradually improves the assembly by adding smaller contigs in each iteration. In contrast to the state-of-the-art long reads error correction technique, which requires high computational resources and long running time on a supercomputer even for bacterial genome datasets, our software can produce comparable assembly using only a standard desktop in a short running time.Comment: Peer-reviewed and presented as part of the 13th Workshop on Algorithms in Bioinformatics (WABI2013

IDENTIFICAÇÃO DE SUPERFÍCIES GEOMÓRFICAS ENTRE ABELARDO LUZ (SC) E ERECHIM (RS) – BASES PARA COMPREENDER A EVOLUÇÃO DO RELEVO NO VALE DO RIO URUGUAI, SUL DO BRASIL

Identificou-se bordas de patamares extensos, patamares dissecados, patamar fortemente dissecado, superfície em elaboração, relevos residuais e remanescente de superfície aplainada. As primeiras correspondem ao prolongamento das superfícies previamente identificadas nas vizinhanças. As demais mostram-se com similaridade topográfica, porém sugerem momentos evolutivos ajustados a incisão do rio Uruguai. Acredita-se que elas evoluíram pelos mesmos mecanismos geradores das superfícies vizinhanças

Identifying seawater intrusion in coastal areas by means of 1D and quasi-2D joint inversion of TDEM and VES data

Seawater intrusion is an increasingly widespread problem in coastal aquifers caused by climate changes –sea-level rise, extreme phenomena like flooding and droughts– and groundwater depletion near to the coastline. To evaluate and mitigate the environmental risks of this phenomenon it is necessary to characterize the coastal aquifer and the salt intrusion. Geophysical methods are the most appropriate tool to address these researches. Among all geophysical techniques, electrical methods are able to detect seawater intrusions due to the high resistivity contrast between saltwater, freshwater and geological layers. The combination of two or more geophysical methods is recommended and they are more efficient when both data are inverted jointly because the final model encompasses the physical properties measured for each methods. In this investigation, joint inversion of vertical electric and time domain soundings has been performed to examine seawater intrusion in an area within the Ferragudo-Albufeira aquifer system (Algarve, South of Portugal). For this purpose two profiles combining electrical resistivity tomography (ERT) and time domain electromagnetic (TDEM) methods were measured and the results were compared with the information obtained from exploration drilling. Three different inversions have been carried out: single inversion of the ERT and TDEM data, 1D joint inversion and quasi-2D joint inversion. Single inversion results identify seawater intrusion, although the sedimentary layers detected in exploration drilling were not well differentiated. The models obtained with 1D joint inversion improve the previous inversion due to better detection of sedimentary layer and the seawater intrusion appear to be better defined. Finally, the quasi-2D joint inversion reveals a more realistic shape of the seawater intrusion and it is able to distinguish more sedimentary layers recognised in the exploration drilling. This study demonstrates that the quasi-2D joint inversion improves the previous inversions methods making it a powerful tool applicable to different research areas.info:eu-repo/semantics/publishedVersio

Electric Field Control of Shallow Donor Impurities in Silicon

We present a tight-binding study of donor impurities in Si, demonstrating the adequacy of this approach for this problem by comparison with effective mass theory and experimental results. We consider the response of the system to an applied electric field: donors near a barrier material and in the presence of an uniform electric field may undergo two different ionization regimes according to the distance of the impurity to the Si/barrier interface. We show that for impurities ~ 5 nm below the barrier, adiabatic ionization is possible within switching times of the order of one picosecond, while for impurities ~ 10 nm or more below the barrier, no adiabatic ionization may be carried out by an external uniform electric field. Our results are discussed in connection with proposed Si:P quantum computer architectures.Comment: 18 pages, 6 figures, submitted to PR

Sustainability improvement of a composite materials' industry through recycling re-engineering process approaches

This case study was aimed at measuring and assessing the potential improvements that couldbe made on the eco-efficiency performance of a composite materials' industry, specifically aglass fibre reinforced plastic (GFRP) pultrusion manufacturing company. For this purpose, allthe issues involved in the pultrusion process of GFRP profiles were analysed, the current ecoefficiency performance of the company was determined, all the procedures applied in theproduction process were revised, and improvement strategies were planned and investigatedwith basis on the performed analysis. The new eco-efficiency ratios were estimated takinginto account the implementation of new proceedings and procedures through re-engineeringthe manufacturing process and recycling approaches. These features lead to significantimprovements on the sequent assessed eco-efficiency ratios, yielding to a more sustainableproduct and manufacturing process of pultruded GFRP profiles