820 research outputs found
New charmonium-like states
In recent years the B-factories and other machines have found evidence for a
large number of new states with hidden charm: candidate h_c(1P), eta_c(2S), and
chi_{c2}(2P) states; the well-established X(3872); enhancements called X(3940),
Y(3940), and Y(4260); and a new structure at 4350 MeV. Various
conventional-charmonium and more exotic interpretations of these data have been
proposed. In this talk we review the current state of the experimental evidence
and the prospects for clarifying the spectrum.Comment: 6 pages, 5 figures. To appear in the proceedings of Beauty 200
Degradation of Aroclor 1221 by microbial populations of the Lagos lagoon
Samples obtained from three locations in the Lagos lagoon were studied for the effect of Aroclor 1221 on their population dynamics. In all three cases, both control and experimental microcosms showedslight increases between day 5 and day 10 with the highest value of 4 × 1010 cfu/ml in control and 1.2 ×1011, 8 × 1010 and 9 × 1010 cfu/ml for Iddo, Apapa and Tin Can samples respectively. Three isolatesnamely, Bacillus subtilis, Alcaligenes eutrophus and Pseudomona aeruginosa were obtained from the microcosms after successive enrichment. All the isolates grew readily on 100 ppm of Aroclor 1221concomitant with production of yellow metabolites in mineral salts medium. Whereas maximal growth was observed at day 12 on biphenyl, that of the polychlorinated biphenyl (PCB) mixture was on day 15.Generally, growth dynamics were similar irrespective of the substrate while typical generation times, with the exception of B. subtilis on Aroclor 1221, ranged insignificantly (P < 0.05) from 6.86 to 8.35 day,thus, suggesting that chlorine substitution has little or no effect on catabolic potentials of the organisms. The degradative capability of these strains suggest that they contribute immensely to theself-purification processes occurring in the lagoon, and this could be exploited for decontamination of PCB polluted aquatic ecosystems
Baryon Antibaryon Nonets
The baryon-antibaryon SU(3) nonets are proposed as a scheme to classify the
increased number of experimentally observed enhancements near the baryon
antibaryon mass threshold. The scheme is similar to the Fermi-Yang-Sakata
model, which was put forth about fifty years ago in explaining the mesons
observed at that time. According to the present scheme, many new
baryon-antibaryon bound states are predicted, and their possible productions in
quarkonium decays and B decays are suggested for experimental search.Comment: 5 pages, 1 figur
The upper limit of the e+e- partial width of X(3872)
The e+e- decay partial width of the recently observed state, X(3872), is
estimated using the ISR data collected at the center of mass energy 4.03 GeV in
e+e- annihilation experiment by BES at BEPC. It is found that the product of
the e+e- partial width and X(3872) --> pi+ pi- J/psi decay branching fraction
is less than 10 eV at 90 % confidence level if the J(PC) of X(3872) is 1(--).
Together with the potential models and other information, we conclude that
X(3872) is very unlikely to be a vector state.Comment: 5 pages, 1 figur
Effect of processing on the quality, composition and antioxidant properties of Terminalia catappa (Indian almond) seed oil
This study was aimed at extracting and purifying T. catappa seed oil with a view to investigating the effect of processing on the composition and antioxidant activity of the oil. Oil was extracted from the dried and roasted T. catappa seed and subjected to degumming and bleaching. The different processed oils were analysed for their fatty acid, phytosterols, and fat soluble vitamins composition. Antioxidant properties of the oils were also determined by measuring the Diphenylpicrylhydrazyl (DPPH) radical scavenging activity and inhibition of heat induced peroxidation. Roasting and processing caused a reduction in acid value, increased peroxide value, but had no effect on the iodine and saponification values of T. catappa oil. Palmitic acid was the most abundant saturated fatty acid (42.466%) while oleic acid was the most abundant unsaturated fatty acid (23.445%). Roasting significantly reduced fatty acid concentration of the oil, and bleaching of both unroasted and roasted oils increased the concentration of fatty acids except linoleic acid. Gamma-sitosterol and Betasitosterol were present in appreciable amounts only in the crude oils. Roasting increased Vitamins A and D concentrations but drastically reduced that of vitamin E. Degumming had no effect on the fat soluble vitamins of T. catappa oil, but bleaching significantly reduced the concentrations of all the vitamins. The DPPH radical scavenging activity of the seed oil was between 26.93 ± 15.42% and 65.47 ± 31.59%. Refining increased the free radical scavenging activity of the unroasted oil, but did not affect the antioxidant activity of roasted oil. The capacity of the oil in preventing heat induced peroxidation was comparable to that of Butylated hydroxytoluene (BHT). Processing of the oil significantly increased its antioxidant activity. Loss of vitamin E did not affect the antioxidant activity of the oil. Thus, suggesting the presence of a heat stable antioxidant in the oil. This study indicated T. catappa seed oil to be potential pharmaceutical oil with good antioxidant characteristics.Key words: Terminalia catappa, composition, antioxidant, processing, oi
A New Basis Function Approach to 't Hooft-Bergknoff-Eller Equations
We analytically and numerically investigate the 't Hooft-Bergknoff-Eller
equations, the lowest order mesonic Light-Front Tamm-Dancoff equations for
U(N_C) and SU(N_C) gauge theories. We find the wavefunction can be well
approximated by new basis functions and obtain an analytic formula for the mass
of the lightest bound state. Its value is consistent with the precedent
results.Comment: 16 pages, 3 figure
Pursuing Gravitational S-Duality
Recently a strong-weak coupling duality in non-abelian non-supersymmetric
theories in four dimensions has been found. An analogous procedure is reviewed,
which allows to find the `dual action' to the gauge theory of dynamical gravity
constructed by the MacDowell-Mansouri model plus the superposition of a
term.Comment: Invited paper to appear in the special issue of the `Journal of
Chaos, Solitons and Fractals' on: "Superstrings, M,F,S,... Theory" (M.S. El
Naschie and C. Castro, editors), 19 pages, LaTeX file, no figure
Spectroscopy of Mesons with Heavy Quarks
I will give a concise overview of mesons with heavy quarks including p-wave
charmed mesons and charmonium (or charmonium-like) states such as X(3872),
Y(4260), X(3940), Y(3940), Z(3930) etc. The effect from the nearby S-wave open
channels on the quark model spectrum is emphasized.Comment: Plenary talk at INPC2007, http://inpc2007.riken.jp/P/P5-zhu.pd
Final state hadronic interactions and non-resonant decays
We evaluate the non-resonant decay amplitude of the process using an approach based on final state hadronic interactions
described in terms of meson exchanges. We conclude that this mechanism
generates inhomogeneities in the Dalitz plot of the B decay.Comment: 6 pages, 5 figures. Major changes. Version accepted for publication
in Phys. Lett.
Towards a Gravitational Analog to S-duality in Non-abelian Gauge Theories
For non-abelian non-supersymmetric gauge theories, generic dual theories have
been constructed. In these theories the couplings appear inverted. However,
they do not possess a Yang-Mills structure but rather are a kind of non-linear
sigma model. It is shown that for a topological gravitational model an analog
to this duality exists.Comment: LaTeX, 14 pages, no figures, minor correction
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