1,736 research outputs found
Extracting W Boson Couplings from the Production of Four Leptons
We consider the processes , including all possible charged lepton combinations, with
regard to measuring parameters characterizing the boson. We calculate at
what level these processes can be used to measure anamolous triple-boson
vertice coupling parameters for the cases of colliders at 500
and 1 center of mass energies.Comment: 13 pages,OCIP/C-93-
Spin-Correlation Coefficients and Phase-Shift Analysis for p+He Elastic Scattering
Angular Distributions for the target spin-dependent observables A,
A, and A have been measured using polarized proton beams at
several energies between 2 and 6 MeV and a spin-exchange optical pumping
polarized He target. These measurements have been included in a global
phase-shift analysis following that of George and Knutson, who reported two
best-fit phase-shift solutions to the previous global p+He elastic
scattering database below 12 MeV. These new measurements, along with
measurements of cross-section and beam-analyzing power made over a similar
energy range by Fisher \textit{et al.}, allowed a single, unique solution to be
obtained. The new measurements and phase-shifts are compared with theoretical
calculations using realistic nucleon-nucleon potential models.Comment: Submitted to Phys. Rev.
[Colored solutions of Yang-Baxter equation from representations of U_{q}gl(2)]
We study the Hopf algebra structure and the highest weight representation of
a multiparameter version of . The commutation relations as well as
other Hopf algebra maps are explicitly given. We show that the multiparameter
universal matrix can be constructed directly as a quantum double
intertwiner, without using Reshetikhin's transformation. An interesting feature
automatically appears in the representation theory: it can be divided into two
types, one for generic , the other for being a root of unity. When
applying the representation theory to the multiparameter universal
matrix, the so called standard and nonstandard colored solutions of the Yang-Baxter equation is obtained.Comment: [14]pages, latex, no figure
The Effect of Foam Rolling Duration on Hamstring Range of Motion
Musculoskeletal health benefits from flexibility training and maintaining a functional, or sport specific, range of motion is important to one’s overall fitness. Commercial foam rollers are commonly used in gyms, therapy clinics and homes, yet data are lacking on the optimal rolling duration and effect on range of motion
Unraveling the Nature of Charge Excitations in LaCuO with Momentum-Resolved Cu -edge Resonant Inelastic X-ray Scattering
Results of model calculations using exact diagonalization reveal the orbital
character of states associated with different Raman loss peaks in Cu -edge
resonant inelastic X-ray scattering (RIXS) from LaCuO. The model
includes electronic orbitals necessary to highlight non-local Zhang-Rice
singlet, charge transfer and - excitations, as well as states with apical
oxygen 2 character. The dispersion of these excitations is discussed with
prospects for resonant final state wave-function mapping. A good agreement with
experiments emphasizes the substantial multi-orbital character of RIXS profiles
in the energy transfer range 1-6 eV.Comment: Original: 4.5 pages. Replaced: 4 pages and 4 figures with updated
content and reference
The upper triangular solutions to the three-state constant quantum Yang-Baxter equation
In this article we present all nonsingular upper triangular solutions to the
constant quantum Yang-Baxter equation
in the three state
case, i.e. all indices ranging from 1 to 3. The upper triangular ansatz implies
729 equations for 45 variables. Fortunately many of the equations turned out to
be simple allowing us to start breaking the problem into smaller ones. In the
end we had a total of 552 solutions, but many of them were either inherited
from two-state solutions or subcases of others. The final list contains 35
nontrivial solutions, most of them new.Comment: 24 Pages in LaTe
Ultracold Neutron Production in a Pulsed Neutron Beam Line
We present the results of an Ultracold neutron (UCN) production experiment in
a pulsed neutron beam line at the Los Alamos Neutron Scattering Center. The
experimental apparatus allows for a comprehensive set of measurements of UCN
production as a function of target temperature, incident neutron energy, target
volume, and applied magnetic field. However, the low counting statistics of the
UCN signal expected can be overwhelmed by the large background associated with
the scattering of the primary cold neutron flux that is required for UCN
production. We have developed a background subtraction technique that takes
advantage of the very different time-of-flight profiles between the UCN and the
cold neutrons, in the pulsed beam. Using the unique timing structure, we can
reliably extract the UCN signal. Solid ortho-D is used to calibrate UCN
transmission through the apparatus, which is designed primarily for studies of
UCN production in solid O. In addition to setting the overall detection
efficiency in the apparatus, UCN production data using solid D suggest that
the UCN upscattering cross-section is smaller than previous estimates,
indicating the deficiency of the incoherent approximation widely used to
estimate inelastic cross-sections in the thermal and cold regimes
A versatile and robust microfluidic device for capillary-sized simple or multiple emulsions production
International audienceUltrasound-vaporizable microdroplets can be exploited for targeted drug delivery. However, it requires customized microfluidic techniques able to produce monodisperse, capillary-sized and biocompatible multiple emulsions. Recent development of microfluidic devices led to the optimization of microdroplet production with high yields, low polydispersity and well-defined diameters. So far, only few were shown to be efficient for simple droplets or multiple emulsions production below 5 microns in diameter, which is required to prevent microembolism after intravenous injection. Here, we present a versatile microchip for both simple and multiple emulsion production. This parallelized system based on microchannel emulsification was designed to produce perfluorocarbon in water or water within perfluorocarbon in water emulsions with capillary sizes (<5 μm) and polydispersity index down to 5 % for in vivo applications such as spatiotemporally-triggered drug delivery using Ultrasound. We show that droplet production at this scale is mainly controlled by interfacial tension forces, how capillary and viscosity ratios influence droplet characteristics and how different production regimes may take place. The better understanding of droplet formation and its relation to applied pressures is supported by observations with a high-speed camera. Compared to previous microchips, this device opens perspectives to produce injectable and biocompatible droplets with a reasonable yield in order to realize preclinical studies in mice
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