1,304 research outputs found
Liquid Argon Hadronic EndCap Production Database
This document describes the contents of the Liquid Argon Hadronic EndCap (HEC) Production Database. At the time of the PRR (Production Readiness Review), the groups responsible for the production of the LAr HEC components and modules were required to provide a detailed plan as to what data should be stored in the production database and how the data should be accessed, displayed and queried in all reasonable foreseeable circumstances. This document describes the final database
Liquid Argon HEC Wheel Assembly Database
This document describes the details of the contents of the LAr Hadronic EndCap Wheel Assembly Database. This database contains the important data from the wheel assembly: mechanical alignment, electrical properties, cabling, and a summary of the readout gap failures. This document describes the final database that is intended mainly for archival purposes. This database should be viewed in conjunction with the HEC module production database that describes the modules that form the wheel and the Feedthrough database that describes the signal feedthroughs. This wheel database lists for instance the location of the modules, the amplifiers to which they are connected, and the details of the alignment measurements. It also details all non-conformances. It is important that for all non-conformances, whether they occurred during wheel assembly or in the B180 cold tests, that a single table be produced of all the non-conformances listing the non-conformance in a format suitable for making offline corrections to the data. This non-conformance table will be derived from a set of queries of this database
I=2 Scattering Phase Shift with two Flavors of Improved Dynamical Quarks
We present a lattice QCD calculation of phase shift including the chiral and
continuum extrapolations in two-flavor QCD. The calculation is carried out for
I=2 S-wave scattering. The phase shift is evaluated for two momentum
systems, the center of mass and laboratory systems, by using the finite volume
method proposed by L\"uscher in the center of mass system and its extension to
general systems by Rummukainen and Gottlieb. The measurements are made at three
different bare couplings , 1.95 and 2.10 using a renormalization
group improved gauge and a tadpole improved clover fermion action, and
employing a set of configurations generated for hadron spectroscopy in our
previous work. The illustrative values we obtain for the phase shift in the
continuum limit are (deg.) , and for , and , which are
consistent with experiment.Comment: 40 page
Cellular memory of hypoxia elicits neuroblastoma metastasis and enables invasion by non-aggressive neighbouring cells
Therapies targeting cancer metastasis are challenging owing to the complexity of the metastatic process and the high number of effectors involved. Although tumour hypoxia has previously been associated with increased aggressiveness as well as resistance to radio- and chemotherapy, the understanding of a direct link between the level and duration of hypoxia and the individual steps involved in metastasis is still missing. Using live imaging in a chick embryo model, we have demonstrated that the exposure of neuroblastoma cells to 1% oxygen for 3 days was capable of (1) enabling cell migration towards blood vessels, (2) slowing down their velocity within blood vessels to facilitate extravasation and (3) promoting cell proliferation in primary and secondary sites. We have shown that cells do not have to be hypoxic anymore to exhibit these acquired capabilities as a long-term memory of prior hypoxic exposure is kept. Furthermore, non-hypoxic cells can be influenced by neighbouring hypoxic preconditioned cells and be entrained in the metastatic progression. The acquired aggressive phenotype relies on hypoxia-inducible factor (HIF)-dependent transcription of a number of genes involved in metastasis and can be impaired by HIF inhibition. Altogether, our results demonstrate the need to consider both temporal and spatial tumour heterogeneity because cells can 'remember' an earlier environment and share their acquired phenotype with their close neighbours. As a consequence, it is necessary to monitor the correct hypoxic markers to be able to predict the consequences of the cells' history on their behaviour and their potential response to therapies
On the precision of chiral-dispersive calculations of scattering
We calculate the combination (the Olsson sum rule)
and the scattering lengths and effective ranges , and ,
dispersively (with the Froissart--Gribov representation) using, at
low energy, the phase shifts for scattering obtained by Colangelo,
Gasser and Leutwyler (CGL) from the Roy equations and chiral perturbation
theory, plus experiment and Regge behaviour at high energy, or directly, using
the CGL parameters for s and s. We find mismatch, both among the CGL
phases themselves and with the results obtained from the pion form factor. This
reaches the level of several (2 to 5) standard deviations, and is essentially
independent of the details of the intermediate energy region ( GeV) and, in some cases, of the high energy behaviour assumed. We discuss
possible reasons for this mismatch, in particular in connection with an
alternate set of phase shifts.Comment: Version to appear in Phys. Rev. D. Graphs and sum rule added. Plain
TeX fil
Thermal production of the meson in the channel
Recent measurements of the pi^+pi^- invariant mass distribution at RHIC show
a shifted peak for the rho meson in 100A GeV in peripheral Au + Au and even in
p + p collisions. A recent theoretical study based on a picture of in-medium
production rates of pions, showed that a large shift could result from a
combination of the Boltzmann factor and the collisional broadening of the rho.
Here we argue that the two-pion density of states is the appropriate quantity
if one assumes a sudden break-up of the system. Methods for calculating the
density of states which include Bose effects are derived. The resulting
invariant mass distributions are significantly enhanced at lower masses and the
rho peak is shifted downward by ~ 35 MeV.Comment: 10 pages, 4 figure
The Inverse Amplitude Method in Scattering in Chiral Perturbation Theory to Two Loops
The inverse amplitude method is used to unitarize the two loop
scattering amplitudes of SU(2) Chiral Perturbation Theory in the ,
and channels. An error analysis in terms of the low energy
one-loop parameters and existing experimental data is
undertaken. A comparison to standard resonance saturation values for the two
loop coefficients is also carried out. Crossing
violations are quantified and the convergence of the expansion is discussed.Comment: (Latex, epsfig) 30 pages, 13 figures, 8 table
Pion Mass Effects in the Large Limit of \chiPT
We compute the large effective action of the non-linear
sigma model including the effect of the pion mass to order
. This action is more complex than the one corresponding
to the chiral limit not only because of the pion propagators but also because
chiral symmetry produce new interactions proportional to .
We renormalize the action by including the appropriate counter terms and find
the renormalization group equations for the corresponding couplings. Then we
estudy the unitarity propierties of the scattering amplitudes. Finally our
results are applied to the particular case of the linear sigma model and also
are used to fit the pion scattering phase shifts.Comment: FT/UCM/18/9
A global fit of and elastic scattering in ChPT with dispersion relations
We apply the one-loop results of the ChPT suplemented
with the inverse amplitude method to fit the available experimental data on
and scattering. With esentially only three parameters we
describe accurately data corresponding to six different channels, namely
and . In addition we
reproduce the first resonances of the and channel with the
right mass corresponding to the and the particles.Comment: 19 pages, 5 figures available on request, FT/UCM/10/9
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