365 research outputs found
Twist-3 Effects in Polarized Photon Structure
The polarized photon structure is described by two spin structure functions
and which can be studied in the future polarized ep
or ee colliders. Here we investigate the QCD twist-3 effects in
to the leading order in QCD.Comment: 4 pages, LaTeX2e, 2 eps figures, ws-ijmpa.cls file included, Talk
given at the 3rd Circum-Pan-Pacific Symposium on High Energy Spin Physics,
Beijing, October 8-13, 2001, to appear in the Proceeding
Increase of total alkalinity due to shoaling of aragonite saturation horizon in the Pacific and Indian Oceans: influence of anthropogenic carbon inputs
Aragonite Saturation Horizon (ASH) shallowed significantly by 25 to 155 m and 16 to 124 m in the Pacific and Indian Ocean respectively in two decades. Apparent Oxygen Utilization (AOU) increased by 3 to 34 and 0.5 to 31.5 μmol kg−1 in the Pacific and Indian Ocean respectively at the depth of ASH during this period. DIC increased by 12.5 to 36.8 and 5.5 to 32 μmol kg−1 in the vicinity of ASH in the Pacific and Indian Ocean respectively due to combined effect of increased anthropogenic CO2 and change in AOU. TA increased significantly by 5 to 10 and 4 to 9.2 μmol kg−1 in the Pacific and Indian Oceans respectively at the ASH most likely as a result of aragonite dissolution. The upward migration of ASH solely due to anthropogenic CO2 amounted to 6 to 58 m in the Pacific and 4 to 44 m in the Indian Ocean
Target Mass Corrections for the Virtual Photon Structure Functions to the Next-to-next-to-leading Order in QCD
We investigate target mass effects in the unpolarized virtual photon
structure functions and in
perturbative QCD for the kinematical region , where
is the mass squared of the probe (target) photon and is
the QCD scale parameter. We obtain the Nachtmann moments for the structure
functions and then, by inverting the moments, we get the expressions in closed
form for up to the next-to-next-to-leading order and
for up to the next-to-leading order, both of which
include the target mass corrections. Numerical analysis exhibits that target
mass effects appear at large and become sizable near , the maximal value of , as the ratio
increases.Comment: 24 pages, LaTeX, 7 eps figures, REVTeX
The corrections to the first moment of the polarized virtual photon structure function
We present the next-to-next-to-leading order () corrections
to the first moment of the polarized virtual photon structure function
in the kinematical region ,
where is the mass squared of the probe (target) photon and
is the QCD scale parameter. In order to evaluate the three-loop-level
photon matrix element of the flavor singlet axial current, we resort to the
Adler-Bardeen theorem for the axial anomaly and we calculate in effect the
two-loop diagrams for the photon matrix element of the gluon operator. The
corrections are found to be about 3% of the sum of the
leading order () andthe next-to-leading order ()
contributions, when and , and the
number of active quark flavors is three to five.Comment: 21 page
Effective Monopole Action at Finite Temperature in SU(2) Gluodynamics
Effective monopole action at finite temperature in SU(2) gluodynamics is
studied on anisotropic lattices. Using an inverse Monte-Carlo method and the
blockspin transformation for space directions, we determine 4-dimensional
effective monopole action at finite temperature. We get an almost perfect
action in the continuum limit under the assumption that the action is composed
of two-point interactions alone. It depends on a physical scale and the
temperature . The temperature-dependence appears with respect to the
spacelike monopole couplings in the deconfinement phase, whereas the timelike
monopole couplings do not show any appreciable temperature-dependence. The
dimensional reduction of the 4-dimensional SU(2) gluodynamics ((SU(2)))
at high temperature is the 3-dimensional Georgi-Glashow model ().
The latter is studied at the parameter region obtained from the dimensional red
uction. We compare the effective instanton action of with the
timelike monopole action obtained from (SU(2)). We find that both agree
very well for at large region. The dimensional reduction
works well also for the effective action.Comment: 34 pages, 23 figure
Vacuum type of SU(2) gluodynamics in maximally Abelian and Landau gauges
The vacuum type of SU(2) gluodynamics is studied using Monte-Carlo
simulations in maximally Abelian (MA) gauge and in Landau (LA) gauge, where the
dual Meissner effect is observed to work. The dual Meissner effect is
characterized by the coherence and the penetration lengths. Correlations
between Wilson loops and electric fields are evaluated in order to measure the
penetration length in both gauges. The coherence length is shown to be fixed in
the MA gauge from measurements of the monopole density around the static
quark-antiquark pair. It is also shown numerically that a dimension 2 gluon
operator A^+A^-(s) and the monopole density has a strong correlation as
suggested theoretically. Such a correlation is observed also between the
monopole density and A^2(s)= A^+A^-(s) + A^3A^3(s) condensate if the remaining
U(1) gauge degree of freedom is fixed to U(1) Landau gauge (U1LA). The
coherence length is determined numerically also from correlations between
Wilson loops and A^+A^-(s) and A^2(s) in MA + U1LA gauge. Assuming that the
same physics works in the LA gauge, we determine the coherence length from
correlations between Wilson loops and A^2(s). Penetration lengths and coherence
lengths in the two gauges are almost the same. The vacuum type of the
confinement phase in both gauges is near to the border between the type 1 and
the type 2 dual superconductors.Comment: 13 pages, 22 figures, RevTeX 4 styl
An Almost Perfect Quantum Lattice Action for Low-energy SU(2) Gluodynamics
We study various representations of infrared effective theory of SU(2)
Gluodynamics as a (quantum) perfect lattice action. In particular we derive a
monopole action and a string model of hadrons from SU(2) Gluodynamics. These
are lattice actions which give almost cut-off independent physical quantities
even on coarse lattices. The monopole action is determined by numerical
simulations in the infrared region of SU(2) Gluodynamics. The string model of
hadrons is derived from the monopole action by using BKT transformation. We
illustrate the method and evaluate physical quantities such as the string
tension and the mass of the lowest state of the glueball analytically using the
string model of hadrons. It turns out that the classical results in the string
model is near to the one in quantum SU(2) Gluodynamics.Comment: 39 pages, 10 figure
Photocatalysis-induced selective decoration of semiconducting single walled carbon nanotubes: hole-doping effect
We have examined the time-dependent effect of the titanium oxide photocatalysis on N-methyl-2-pyrrolidone individually dispersed single walled carbon nanotube (SWNT) suspensions. From optical spectroscopic studies, we found a selective decoration of the semiconducting tubes. Such selectivity is attributed to the preferential attack of the photogenerated active species on the hole-doped semiconducting SWNTs.ArticleCHEMICAL COMMUNICATIONS. 46(37):6977-6979 (2010)journal articl
Blocking of lattice monopoles from the continuum in hot lattice gluodynamics
The Abelian monopoles in lattice gluodynamics are associated with continuum
monopoles blocked to the lattice. This association allows to predict the
lattice monopole action and density of the (squared) monopole charges from a
continuum monopole model. The method is applied to the static monopoles in high
temperature gluodynamics. We show that the numerical data both for the density
and the action of the lattice monopoles can be described in terms of a Coulomb
gas of Abelian monopoles in the continuum.Comment: 23 pages, 9 EPS figures, LaTeX2e uses JHEP3 class file; replaced to
match published versio
Multiwavelength Monitoring of the BL Lacertae Object PKS 2155-304 in May 1994. II. The IUE Campaign
PKS 2155-304, the brightest BL Lac object in the ultraviolet sky, was
monitored with the IUE satellite at ~1 hour time-resolution for ten nearly
uninterrupted days in May 1994. The campaign, which was coordinated with EUVE,
ROSAT, and ASCA monitoring, along with optical and radio observations from the
ground, yielded the largest set of spectra and the richest short time scale
variability information ever gathered for a blazar at UV wavelengths. The
source flared dramatically during the first day, with an increase by a factor
~2.2 in an hour and a half. In subsequent days, the flux maintained a nearly
constant level for ~5 days, then flared with ~35% amplitude for two days. The
same variability was seen in both short- and long-wavelength IUE light curves,
with zero formal lag (~<2 hr), except during the rapid initial flare, when the
variations were not resolved. Spectral index variations were small and not
clearly correlated with flux. The flux variability observed in the present
monitoring is so rapid that for the first time, based on the UV emission alone,
the traditional Delta L/Delta t limit indicating relativistic beaming is
exceeded. The most rapid variations, under the likely assumption of synchrotron
radiation, lead to a lower limit of 1 G on the magnetic field strength in the
UV emitting region. These results are compared with earlier intensive
monitoring of PKS 2155-304 with IUE in November 1991, when the UV flux
variations had completely different characteristics.Comment: 45 pages, Latex, 11 PostScript figures, to appear in The
Astrophysical Journa
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