7,350 research outputs found
Analytical and Numerical Flash-Algorithms for Track Fits
Flash-algorithm track-reconstruction routines with speed factors 3000-4000 in
excess those of traditional iterative routines are presented.
The methods were successfully tested in the alignment of the Test Beam setup
for the ATLAS Pixel Detector
MCM-D modules yielding a
60 fold increase in alignment resolution over iterative routines, for the
same amount of alocated CPU time.Comment: 6 pages, 3 figure
Beyond the standard model physics at RHIC in polarized pp collision
A polarized hadron collider experiment must have a great discovery potential
for a search of physics beyond the standard model. Experimental data of various
symmetry tests at RHIC are going to be obtained within a few years. The author
developed a simulation tool, studying a sensitivity of hunting contact
interaction at RHIC by measuring parity violating spin asymmetries.Comment: 8 pages, 9 figure, Proc. of Praha-SPIN-200
Determination of the magnetic susceptibility of the quark condensate using radiative heavy meson decays
We use a light-cone sum rule (LCSR) analysis of the branching ratios of
radiative meson decays to contrain the value of the magnetic susceptibility of
the quark condensate . For the first time, we use a complete set of
three-particle distribution amplitudes that enables us to give a consistent
prediction for the branching ratios. Furthermore we will make use of a very
recent update of several non-perturbative parameters. Our final result for
(assuming asymptotic wave
functions) agrees with the currently used value of .Comment: 21 pages, 4 figures, references adde
New calibrations and time stability of the response of the INTERCAST CR-39
We present new calibrations of different production batches (from 1989 to
1999) of the INTERCAST CR-39, using the BNL-AGS 1 A GeV iron beam. The
comparison with previous results, obtained with the 158 A GeV lead beam from
the CERN-SPS shows that, while each production batch has a different
calibration curve (mainly due to minor differences in the production
conditions), the aging effect is negligible. We also tested the dependence of
the CR-39 response from the time elapsed between exposure and analysis (fading
effect). The fading effect, if present, is less than 10%. It may be compatible
with the experimental uncertainties on the bulk etching rate vB.Comment: 9 pages, 4 EPS figures, .pdf file. Talk presented by M. Giorgini at
the 20 Int. Conf. on Nuclear Tracks in Solids, Portoroz (Slovenia), Aug
28-Sep 1, 200
Quantum switch for single-photon transport in a coupled superconducting transmission line resonator array
We propose and study an approach to realize quantum switch for single-photon
transport in a coupled superconducting transmission line resonator (TLR) array
with one controllable hopping interaction. We find that the single-photon with
arbitrary wavevector can transport in a controllable way in this system. We
also study how to realize controllable hopping interaction between two TLRs via
a superconducting quantum interference device (SQUID). When the frequency of
the SQUID is largely detuned from those of the two TLRs, the variables of the
SQUID can be adiabatically eliminated and thus a controllable interaction
between two TLRs can be obtained.Comment: 4 pages,3 figure
Comment on decay puzzle
We analize the current data on -lepton decays and show that they are
consistent with the Standard ModelComment: 5 pages, 1 figure (available from de authors), Latex, preprint
IFT-P.022/9
Factorization of the charge correlation function in oscillations
Extraction of the mass difference from oscillations
involves tagging of bottom flavour at production and at decay. We show that the
asymmetry between the unmixed and mixed events factorizes into two parts, one
depending on the production-tag and the other on the decay-tag.Comment: 6 pages, Latex, no figure
Leptogenesis in models with multi-Higgs bosons
We study the leptogenesis scenario in models with multi-Higgs doublets. It is
pointed out that the washing-out process through the effective dimension five
interactions, which has not been taken into account seriously in the
conventional scenario, can be effective, and the resultant baryon asymmetry can
be exponentially suppressed. This fact implies new possible scenario where the
observed baryon asymmetry is the remnant of the washed out lepton asymmetry
which was originally much larger than the one in the conventional scenario. Our
new scenario is applicable to some neutrino mass matrix models which predict
too large CP-violating parameter and makes them viable through the washing-out
process.Comment: Latex 2e, 11 pages, 2 figures. Many parts in the original manuscript
have been revised, but conclusions are unchange
Magnetic properties of polypyrrole - coated iron oxide nanoparticles
Iron oxide nanoparticles were prepared by sol -gel process. Insitu
polymerization of pyrrole monomer in the presence of oxygen in iron oxide
ethanol suspension resulted in a iron oxide - polypyrrole nanocomposite. The
structure and magnetic properties were investigated for varying pyrrole
concentrations. The presence of the gamma - iron oxide phase and polypyrrole
were confirmed by XRD and FTIR respectively. Agglomeration was found to be
comparatively much reduced for the coated samples, as shown by TEM. AC
susceptibility measurements confirmed the superparamagnetic behaviour.
Numerical simulations performed for an interacting model system are performed
to estimate the anisotropy and compare favourably with experimental results.Comment: 11 pages,8 figure
Gamma-ray Constraints on Effective Interactions of the Dark Matter
Using an effective interaction approach to describe the interactions between
the dark matter particle and the light degrees of freedom of the standard
model, we calculate the gamma-ray flux due to the annihilation of the dark
matter into quarks, followed by fragmentation into neutral pions which
subsequently decay into photons. By comparison to the mid-latitude data
released from the Fermi-LAT experiment, we obtain useful constraints on the
size of the effective interactions and they are found to be comparable to those
deduced from collider, gamma-ray line and anti-matter search experiments.
However, the two operators induced by scalar and vector exchange among
fermionic dark matter and light quarks that contribute to spin-independent
cross sections are constrained more stringently by the recent XENON100 data.Comment: 22 pages, 4 figures; title fixed and a couple of references adde
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