60,283 research outputs found
BFT Hamiltonian embedding for SU(3) Skyrmion
We newly apply the Batalin, Fradkin and Tyutin (BFT) formalism to the SU(3)
flavor Skyrmion model to investigate the Weyl ordering correction to the
structure of the hyperfine splittings of strange baryons. On the other hand,
the Berry phases and Casimir effects are also discussed.Comment: 14 pages, modified titl
SPEAR Far Ultraviolet Spectral Images of the Cygnus Loop
We present far-ultraviolet (FUV) spectral images, measured at C IV 1550, He
II 1640, Si IV+O IV] 1400, and O III] 1664, of the entire Cygnus Loop, observed
with the Spectroscopy of Plasma Evolution from Astrophysical Radiation (SPEAR)
instrument, also known as FIMS. The spatial distribution of FUV emission
generally corresponds with a limb-brightened shell, and is similar to optical,
radio and X-ray images. The features found in the present work include a
``carrot'', diffuse interior, and breakout features, which have not been seen
in previous FUV studies. Shock velocities of 140-160 km/s is found from a line
ratio of O IV] to O III], which is insensitive not only to resonance scattering
but also to elemental abundance. The estimated velocity indicates that the fast
shocks are widespread across the remnant. By comparing various line ratios with
steady-state shock models, it is also shown that the resonance scattering is
widespread.Comment: 13 pages, 3 figures, 1 table, accepted for publication in ApJ
Note: Precision viscosity measurement using suspended microchannel resonators
We report the characterization of a suspended microchannel resonator (SMR) for viscosity measurements in a low viscosity regime (\u3c10 mPa s) using two measurement schemes. First, the quality factor (Q-factor) of the SMR was characterized with glycerol-water mixtures. The measured Q-factor at 20 °C exhibits a bilinear behavior with the sensitivity of 1281 (mPa s)−1 for a lower (1-4 mPa s) and 355 (mPa s)−1 for a higher viscosity range (4-8 mPa s), respectively. The second scheme is the vibration amplitude monitoring of the SMR running in a closed loop feedback. When compared in terms of the measurement time, the amplitude-based measurement takes only 0.1 ∼ 1 ms while the Q-factor-based measurement takes ∼30 s. However, the viscosity resolution of the Q-factor-based measurement is at least three times better than the amplitude-based measurement. By comparing the Q-factors of heavy water and 9.65 wt.% glycerol-water mixture that have very similar viscosities but different densities, we confirmed that the SMR can measure the dynamic viscosity without the density correction. The obtained results demonstrate that the SMR can measure the fluid viscosity with high precision and even real-time monitoring of the viscosity change is possible with the amplitude-based measurement scheme
Strange Quark PDFs and Implications for Drell-Yan Boson Production at the LHC
Global analyses of Parton Distribution Functions (PDFs) have provided
incisive constraints on the up and down quark components of the proton, but
constraining the other flavor degrees of freedom is more challenging.
Higher-order theory predictions and new data sets have contributed to recent
improvements. Despite these efforts, the strange quark PDF has a sizable
uncertainty, particularly in the small x region. We examine the constraints
from experiment and theory, and investigate the impact of this uncertainty on
LHC observables. In particular, we study W/Z production to see how the s-quark
uncertainty propagates to these observables, and examine the extent to which
precise measurements at the LHC can provide additional information on the
proton flavor structure.Comment: 14 pages, 11 figures, added reference
Generating Function for Particle-Number Probability Distribution in Directed Percolation
We derive a generic expression for the generating function (GF) of the
particle-number probability distribution (PNPD) for a simple reaction diffusion
model that belongs to the directed percolation universality class. Starting
with a single particle on a lattice, we show that the GF of the PNPD can be
written as an infinite series of cumulants taken at zero momentum. This series
can be summed up into a complete form at the level of a mean-field
approximation. Using the renormalization group techniques, we determine
logarithmic corrections for the GF at the upper critical dimension. We also
find the critical scaling form for the PNPD and check its universality
numerically in one dimension. The critical scaling function is found to be
universal up to two non-universal metric factors.Comment: (v1,2) 8 pages, 5 figures; one-loop calculation corrected in response
to criticism received from Hans-Karl Janssen, (v3) content as publishe
Anisotropy of in-plane magnetization due to nodal gap structure in the vortex state
We examine the interplay between anisotropy of the in-plane magnetization and
the nodal gap structure on the basis of the approximate analytic solution in
the quasiclassical formalism. We show that a four-fold oscillation appears in
the magnetization, and its amplitude changes sign at an intermediate field. The
high-field oscillation originates from the anisotropy of the upper critical
field, while the low-field behavior can be understood by the thermally
activated quasiparticles near nodes depending on the applied field angles. The
temperature dependence of the magnetization also shows a similar sign change.
The anisotropy of the magnetization offers a possible measurement to identify
the gap structure directly for a wide class of type II superconductors.Comment: 4 pages, 4 figure
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