114 research outputs found
Monte Carlo Eikonal Scattering
Monte Carlo evaluation is used to calculate heavy-ion elastic scattering
including the center-of-mass correction and the Coulomb interaction.Angular
distributions are presented for a number of nuclear pairs over a wide energy
range using nucleon-nucleon scattering parameters taken from phase-shift
analyses and densities from independent sources. A technique for the efficient
expansion of the Glauber amplitude in partial waves is developed
Geometrical destruction of the global phase coherence in ultrathin superconducting cylinders
The global phase coherence in doubly-connected superconductors leads to
fluxoid quantization, allowing the superfluid velocity vs to be controlled by
an applied magnetic flux. In ultrasmall samples this quantization requirement
leads, surprisingly, to the destruction of the phase coherence itself around
half-integer flux quanta, because of the sample-size-induced growth in vs, as
predicted by de Gennes. We report observations of the predicted phenomenon in
ultrathin Al and Au0.7In0.3 cylinders, and the corresponding phase diagram for
ultrathin superconducting cylinders. The new phase diagram features
disconnected superconducting regions, as opposed to the single one seen in the
conventional Little-Parks experiment.Comment: pdf file, 9 pages plus 5 figure
User-centered design and evaluation of RxMAGIC: A Prescription Management And General Inventory Control system for free clinic dispensaries
Medication management is a complex and expensive multistage process that covers the prescribing and ordering, order communication, dispensing, administering, and monitoring and use of prescription medications. While challenges in medication management are ubiquitous across all settings, they can be particularly exacerbated in a free clinic that serves a medically vulnerable population. These patients suffer from financial constraints, poor health literacy, multiple chronic conditions, and medication non-adherence. Clinical pharmacists play an integral role in the provision of healthcare services to these patients and could benefit from the use of medication management information technology (MMIT) to provide efficiencies in the tracking, provision, and use of medications. While MMITs exist, they are not designed to support the unique needs of pharmacists in these settings
The KATRIN Pre-Spectrometer at reduced Filter Energy
The KArlsruhe TRItium Neutrino experiment, KATRIN, will determine the mass of
the electron neutrino with a sensitivity of 0.2 eV (90% C.L.) via a measurement
of the beta-spectrum of gaseous tritium near its endpoint of E_0 =18.57 keV. An
ultra-low background of about b = 10 mHz is among the requirements to reach
this sensitivity. In the KATRIN main beam-line two spectrometers of MAC-E
filter type are used in a tandem configuration. This setup, however, produces a
Penning trap which could lead to increased background. We have performed test
measurements showing that the filter energy of the pre-spectrometer can be
reduced by several keV in order to diminish this trap. These measurements were
analyzed with the help of a complex computer simulation, modeling multiple
electron reflections both from the detector and the photoelectric electron
source used in our test setup.Comment: 22 pages, 12 figure
A New Interpretation of Flux Quantization
We study the effect of Aharonov-Bohm flux on the superconducting state in
metallic cylinders. Although Byers and Yang attributed flux quantization to the
flux-dependent minimum of kinetic energies of the Cooper pairs, it is shown
that kinetic energies do not produce any discernible oscillations in the free
energy of the superconducting state (relative to that of normal state) as a
function of the flux. This result is indeed anticipated by the observation of
persistent current in normal metal rings at low temperature. Instead, we have
found that pairing interaction depends on the flux, leading to flux
quantization. When the flux ) is given by (with
integer n), the pairing interaction and the free energy become unchanged (even
n) or almost unchanged (odd n), due to degenerate-state pairing resulting from
the energy level crossing. As a result, flux quantization and Little-Parks
oscillations follow.Comment: Revtex, 10 pages, 6 figures, For more information, send me an e-mail
at [email protected]
Semileptonic Branching Fraction of Charged and Neutral B Mesons
An examination of leptons in events tagged by reconstructed
decays yields semileptonic branching fractions of for charged and for neutral mesons.
This is the first measurement for charged . Assuming equality of the charged
and neutral semileptonic widths, the ratio is
equivalent to the ratio of lifetimes. A postscript version is available through
World-Wide-Web in http://w4.lns.cornell.edu/public/CLNS/1994Comment: 9 pages (in REVTEX format) Preprint CLNS94-1286, CLEO 94-1
Precision Measurement of the Mass Difference
We have measured the vector-pseudoscalar mass splitting , significantly more precise than the previous
world average. We minimize the systematic errors by also measuring the
vector-pseudoscalar mass difference using the radiative
decay , obtaining
. This is
then combined with our previous high-precision measurement of
, which used the decay . We also
measure the mass difference MeV, using the
decay modes of the and mesons.Comment: 18 pages uuencoded compressed postscript (process with uudecode then
gunzip). hardcopies with figures can be obtained by sending mail to:
[email protected]
Observation of a New Charmed Strange Meson
Using the CLEO-II detector, we have obtained evidence for a new meson
decaying to . Its mass is
{}~MeV/ and its width is ~MeV/. Although we do not
establish its spin and parity, the new meson is consistent with predictions for
an , , charmed strange state.Comment: 9 pages uuencoded compressed postscript (process with uudecode then
gunzip). hardcopies with figures can be obtained by sending mail to:
[email protected]
Production and Decay of D_1(2420)^0 and D_2^*(2460)^0
We have investigated and final states and
observed the two established charmed mesons, the with mass
MeV/c and width MeV/c and
the with mass MeV/c and width
MeV/c. Properties of these final states, including
their decay angular distributions and spin-parity assignments, have been
studied. We identify these two mesons as the doublet predicted
by HQET. We also obtain constraints on {\footnotesize } as a function of the cosine of the relative phase of the two
amplitudes in the decay.Comment: 15 pages in REVTEX format. hardcopies with figures can be obtained by
sending mail to: [email protected]
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