820 research outputs found
QCD corrections to Upsilon production via color-octet states at the Tevatron and LHC
The NLO QCD corrections to Upsilon production via S-wave color-octet states
Upsilon(^1S_0^8,^3S_1^8) at the Tevatron and LHC is calculated. The K factors
of total cross section (ratio of NLO to LO) are 1.313 and 1.379 for
Upsilon(^1S_0^8) and Upsilon(^3S_1^8) at the Tevatron, while at the LHC they
are 1.044 and 1.182, respectively. By fitting the experimental data from the
D0, the matrix elements for S-wave color-octet states are obtained. And new
predictions for Upsilon production are presented. The prediction for the
polarization of inclusive Upsilon contains large uncertainty rising from the
polarization of Upsilon from feed-down of chi_b. To further clarify the
situation, new measurements on the production and polarization for direct
Upsilon are expected.Comment: 13 pages, 10 Figure
Arsenic trioxide treatment of rabbit liver VX-2 carcinoma via hepatic arterial cannulationinduced apoptosis and decreased levels of survivin in the tumor tissue
Aim To investigate the role of tumor apoptosis-inhibitory
protein survivin in arsenic trioxide-induced apoptosis in
VX-2 carcinoma in the rabbit liver by means of transcatheter
arterial chemoembolization.
Methods Sixteen rabbits with 32 implanted hepatic VX-2
tumors were randomly divided into two groups. The experimental
group received 2 mg of arsenic trioxide and
1 mL of ultra-fluid lipiodol co-injected via hepatic arterial
cannulation and the control group received only 1 mL of
lipiodol. Animals were sacrificed 3 weeks after trans-catheterial
arterial chemoembolization. Tumor tissue and tumor-
peripheral tissue were collected for analysis. Terminal
deoxynucleotidyl transferase-mediated dUTP nick-end-labeling
staining was used to assess tumor cells apoptosis.
Immunohistochemistry was used to assess the presence
of survivin protein. Reverse transcription polymerase chain
reaction was used to determine the expression of survivin
gene.
Results The number of apoptotic cells significantly increased
in the tumor tissue (5.20 ± 0.60%) compared to
tumor-peripheral tissue (1.29 ± 0.42%) of the arsenic trioxide-
treated group. Survivin expression levels in the tumor
tissue were significantly reduced in arsenic trioxidetreated
group (7.68 ± 0.65) compared to the control group
(35.30 ± 4.63).
Conclusion Transcatheter arterial chemoembolization
with arsenic trioxide induced apoptosis of VX-2 carcinoma,
in which tumor apoptosis-inhibitory protein survivin may
have played a role
Inversion formula of multifractal energy dissipation in 3D fully developed turbulence
The concept of inverse statistics in turbulence has attracted much attention
in the recent years. It is argued that the scaling exponents of the direct
structure functions and the inverse structure functions satisfy an inversion
formula. This proposition has already been verified by numerical data using the
shell model. However, no direct evidence was reported for experimental three
dimensional turbulence. We propose to test the inversion formula using
experimental data of three dimensional fully developed turbulence by
considering the energy dissipation rates in stead of the usual efforts on the
structure functions. The moments of the exit distances are shown to exhibit
nice multifractality. The inversion formula between the direct and inverse
exponents is then verified.Comment: 3 RevTex pages including 3 eps figure
Low-energy Scattering of System and the Resonance-like Structure
In this paper, low-energy scattering of the meson
system is studied within L\"uscher's finite-size formalism using
twisted mass gauge field configurations. With three different pion mass values,
the -wave threshold scattering parameters, namely the scattering length
and the effective range , are extracted in channel. Our
results indicate that, in this particular channel, the interaction between the
two vector charmed mesons is weakly repulsive in nature hence do not support
the possibility of a shallow bound state for the two mesons, at least for the
pion mass values being studied. This study provides some useful information on
the nature of the newly discovered resonance-like structure
observed in various experiments.Comment: 11 pages, 6 figures. arXiv admin note: substantial text overlap with
arXiv:1403.131
A Lattice Study of Near-threshold Scattering
In this exploratory lattice study, low-energy near threshold scattering of
the meson system is analyzed using lattice QCD with
twisted mass fermion configurations. Both s-wave () and p-wave
() channels are investigated. It is found that the interaction between
the two charmed mesons is attractive near the threshold in both channels. This
calculation provides some hints in the searching of resonances or bound states
around the threshold of system.Comment: 20 pages, 15 figures, matches the version on PR
Two Photon Decays of from Lattice QCD
We present an exploratory lattice study for the two-photon decay of
using twisted mass lattice QCD gauge configurations generated by the
European Twisted Mass Collaboration. Two different lattice spacings of
fm and fm are used in the study, both of which are of
physical size of 2. The decay widths are found to be KeV for the
coarser lattice and KeV for the finer lattice respectively where the
errors are purely statistical. A naive extrapolation towards the continuum
limit yields KeV which is smaller than the previous
quenched result and most of the current experimental results. Possible reasons
are discussed.Comment: 13 pages, 7 figures; matches the published versio
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