2,141,297 research outputs found
Dynamical quark loop light-by-light contribution to muon g-2 within the nonlocal chiral quark model
The hadronic corrections to the muon anomalous magnetic moment a_mu, due to
the gauge-invariant set of diagrams with dynamical quark loop light-by-light
scattering insertions, are calculated in the framework of the nonlocal chiral
quark model. These results complete calculations of all hadronic light-by-light
scattering contributions to a_mu in the leading order in the 1/Nc expansion.
The result for the quark loop contribution is
a_mu^{HLbL,Loop}=(11.0+-0.9)*10^(-10), and the total result is
a_mu^{HLbL,NxQM}=(16.8+-1.2)*10^(-10).Comment: 11 pages, 5 figures, 1 tabl
Singlet VA \tilde V correlator within the instanton vacuum model
The correlator of singlet axial-vector and vector currents in the external
electromagnetic field is studied within the instanton liquid model of QCD
vacuum. In the chiral limit we calculate the longitudinal w_L^0 and transversal
w_T^0 with respect to axial-vector index invariant amplitudes at arbitrary
momentum transfer q. It is demonstrated how the anomalous longitudinal part of
the correlator is renormalized at low momenta due to the presence of the U_A(1)
anomaly.Comment: 9 pages, 4 figure
A new N = 8 nonlinear supermultiplet
We construct a new off-shell , nonlinear
supermultiplet proceeding from the nonlinear realization of
the , superconformal group in its
supercoset . The irreducibility constraints for the
superfields automatically follow from appropriate covariant conditions on the
-valued Cartan superforms. We present the most general
sigma-model type action for supermultiplet. The relations
between linear and nonlinear supermultiplets and linear
vector supermultiplet are discussed.Comment: 15 pages, LaTeX file, PACS numbers: 11.30.Pb, 03.65.-
Hartree-Fock-Bogoliubov Calculations in Coordinate Space: Neutron-Rich Sulfur, Zirconium, Cerium, and Samarium Isotopes
Using the Hartree-Fock-Bogoliubov (HFB) mean field theory in coordinate
space, we investigate ground state properties of the sulfur isotopes from the
line of stability up to the two-neutron dripline (). In particular,
we calculate two-neutron separation energies, quadrupole moments, and rms-radii
for protons and neutrons. Evidence for shape coexistence is found in the very
neutron-rich sulfur isotopes. We compare our calculations with results from
relativistic mean field theory and with available experimental data. We also
study the properties of neutron-rich zirconium (), cerium
(), and samarium () isotopes which exhibit very large
prolate quadrupole deformations.Comment: 7 pages, 6 figures, 2 tables submitted to Phys. Rev.
Bose-Einstein condensates in `giant' toroidal magnetic traps
The experimental realisation of gaseous Bose-Einstein condensation (BEC) in
1995 sparked considerable interest in this intriguing quantum fluid. Here we
report on progress towards the development of an 87Rb BEC experiment in a large
(~10cm diameter) toroidal storage ring. A BEC will be formed at a localised
region within the toroidal magnetic trap, from whence it can be launched around
the torus. The benefits of the system are many-fold, as it should readily
enable detailed investigations of persistent currents, Josephson effects, phase
fluctuations and high-precision Sagnac or gravitational interferometry.Comment: 5 pages, 3 figures (Figs. 1 and 2 now work
Microbial Population and Fermentation Characteristic in Response to Sapindus Rarak Mineral Block Supplementation
This experiment was conducted to evaluate the effect of supplementation with lerak extract combined with mineral block on protozoal and bacterial population, and fermentation characteristic in vitro. The experimental design was completely randomized block design with 3 treatments and 4 replications. Control diet was a substrate that consisted of concentrate, forage and feed block with ratio 50 : 48 : 2, respectively. The treatments as a substrate were: control diet (C), C + 0.09% lerak extract, and C + 0.18% lerak extract from the total ration. Variables observed were protozoal and bacterial population, dry matter and organic matter degradability, N-NH3 and total volatile fatty acid (VFA) concentration. Data were analyzed using analysis of variance (ANOVA). The result showed that there were no significant effect (P>0.05) for all parameter measured with lerak extract supplementation up to 0.18% in the presence of mineral block. However, supplementation of lerak extract 0.18% only slightly reduced protozoal numbers but tended to increase bacterial numbers. Dry matter and organic matter degradability and concentration of N-NH3 were similar among treatments. Volatile fatty acids profile changed which propionate tended to increase and acetate tended to decrease and ratio of acetate to propionate tended to decrease. In conclusion, addition of lerak extract up to 0.18% from total ration in the presence of mineral block was not yet effective to depress protozoal population, but could modify fermentation characteristic in vitro
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