270 research outputs found
Flux flow of Abrikosov-Josephson vortices along grain boundaries in high-temperature superconductors
We show that low-angle grain boundaries (GB) in high-temperature
superconductors exhibit intermediate Abrikosov vortices with Josephson cores,
whose length along GB is smaller that the London penetration depth, but
larger than the coherence length. We found an exact solution for a periodic
vortex structure moving along GB in a magnetic field and calculated the
flux flow resistivity , and the nonlinear voltage-current
characteristics. The predicted dependence describes well our
experimental data on unirradiated and irradiated
bicrystals, from which the core size , and the intrinsic depairing
density on nanoscales of few GB dislocations were measured for the
first time. The observed temperature dependence of
indicates a significant order parameter suppression in current channels between
GB dislocation cores.Comment: 5 pages 5 figures. Phys. Rev. Lett. (accepted
Inflammatory myofibroblastic tumor after lung transplant-A rare and aggressive complication. A case report.
Introduction
Malignant diseases are well-known complications after lung transplantation (LT). Among these, inflammatory myofibroblastic tumor (IMT) is a rare neoplasm with a not well-known and often aggressive biological behavior.
Material and Methods
We hereby describe 2 cases of cystic fibrosis patients who underwent bilateral sequential LT (BSLT) complicated by IMT.
Results
A 26-year-old man presented a right endobronchial lesion 6 months after BSLT. Two consecutive fiber bronchoscopic biopsies showed granulation tissue. For the persistent lesion growth, the patient underwent a transthoracic biopsy showing histologic diagnosis of IMT. Therefore, he underwent to right pneumonectomy that was unfortunately complicated after 6 months with a late bronchopleural fistula and empyema with exitus 6 months later. A 31-year-old woman 1 year after BSLT presented with a left voluminous pleural-parenchymal lesion; the histologic examination after biopsy revealed an IMT. She underwent a removal of the lesion with a macroscopic R0 resection. Histologic, immunophenotypic, and cytogenetic examinations showed a strong overexpression of anaplastic lymphoma kinase requiring biological adjuvant therapies; however, the patient refused it. Four years later, she presented a recurrence treated with debulking procedure and adjuvant radiotherapy. At last follow-up, the patient was alive with stable disease and optimal graft function.
Conclusions
Although IMT is a rare complication after lung transplant, to obtain a careful diagnosis, an early and aggressive treatment is mandatory
Measurement of the Helicity Fractions of W Bosons from Top Quark Decays Using Fully Reconstructed top-antitop Events with CDF II
We present a measurement of the fractions F_0 and F_+ of longitudinally
polarized and right-handed W bosons in top quark decays using data collected
with the CDF II detector. The data set used in the analysis corresponds to an
integrated luminosity of approximately 318 pb -1. We select ttbar candidate
events with one lepton, at least four jets, and missing transverse energy. Our
helicity measurement uses the decay angle theta*, which is defined as the angle
between the momentum of the charged lepton in the W boson rest frame and the W
momentum in the top quark rest frame. The cos(theta*) distribution in the data
is determined by full kinematic reconstruction of the ttbar candidates. We find
F_0 = 0.85 +0.15 -0.22 (stat) +- 0.06 (syst) and F_+ = 0.05 +0.11 -0.05 (stat)
+- 0.03 (syst), which is consistent with the standard model prediction. We set
an upper limit on the fraction of right-handed W bosons of F_+ < 0.26 at the
95% confidence level.Comment: 11 pages, 2 figures, submitted to Phys. Rev.
Searches for Direct Pair Production of Supersymmetric Top and Supersymmetric Bottom Quarks in p-pbar Collisions at sqrt(s)=1.96 TeV
We search for direct pair production of supersymmetric top quarks and
supersymmetric bottom quarks in proton-antiproton collisions at sqrt(s)=1.96
TeV, using 295 pb^-1 of data recorded by the Collider Detector at Fermilab (CDF
II) experiment. The supersymmetric top (supersymmetric bottom) quarks are
selected by reconstructing their decay into a charm (bottom) quark and a
neutralino, which is assumed to be the lightest supersymmetric particle. The
signature of such processes is two energetic heavy-flavor jets and missing
transverse energy. The number of events that pass our selection for each search
process is consistent with the expected standard model background. By comparing
our results to the theoretical production cross sections of the supersymmetric
top and supersymmetric bottom quarks in the minimal supersymmetric standard
model, we exclude, at a 95% confidence level in the frame of that model, a
supersymmetric top quark mass up to 132 GeV/c^2 for a neutralino mass of 48
GeV/c^2, and a supersymmetric bottom quark mass up to 193 GeV/c^2 for a
neutralino mass of 40 GeV/c^2.Comment: 12 pages, 5 figures, submitted to Phys. Rev.
Polarizations of J/psi and psi(2S) Mesons Produced in ppbar Collisions at 1.96 TeV
We have measured the polarizations of \jpsi and \psiprime mesons as
functions of their transverse momentum \pt when they are produced promptly in
the rapidity range with \pt \geq 5 \pgev. The analysis is performed
using a data sample with an integrated luminosity of about 800 \ipb collected
by the CDF II detector. For both vector mesons, we find that the polarizations
become increasingly longitudinal as \pt increases from 5 to 30 \pgev. These
results are compared to the predictions of nonrelativistic quantum
chromodynamics and other contemporary models. The effective polarizations of
\jpsi and \psiprime mesons from -hadron decays are also reported.Comment: 8 pages, 7 figures, published in Physical Review Letter
MODERATED POSTER SESSION: Don't look only at the left ventricule: Wednesday 3 December 2014, 09:00-16:00 * Location: Moderated Poster area
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Measurement of the top-quark mass using missing +jets events with secondary vertex -tagging at CDF II
We present a measurement of the top-quark mass in collisions at
\hbox{} TeV which uses events with an inclusive signature of
missing transverse energy and jets. % The event selection is sensitive to
independent of the
lepton flavor, and results in a large acceptance for decays. %
All-hadronic decays and events with identified electrons or muons are
vetoed to provide a statistically independent sample with respect to all
previous measurements. % The top-quark mass is inferred from the distribution
of the scalar sum of all jet transverse energies and the missing transverse
energy. Using 311 pb of integrated luminosity recorded by the Collider
Detector at Fermilab, we measure a top-quark mass (stat.)(syst.) GeV/. While the uncertainty on
is larger than that of other measurements, the result is statistically
uncorrelated with those of other methods, and thus can help to reduce the
overall uncertainty when combined with other existing measurements.Comment: 8 pages, 4 figure
Limits on Anomalous Triple Gauge Couplings in ppbar Collisions at sqrt{s}=1.96 TeV
We present a search for anomalous triple gauge couplings (ATGC) in WW and WZ
boson production. The boson pairs are produced in ppbar collisions at
sqrt{s}=1.96 TeV, and the data sample corresponds to 350 pb-1 of integrated
luminosity collected with the CDF II detector at the Fermilab Tevatron. In this
search one W decays to leptons, and the other boson (W or Z) decays
hadronically. Combining with a previously published CDF measurement of Wgamma
boson production yields ATGC limits of -0.18 < lambda < 0.17 and -0.46 < Delta
kappa < 0.39 at the 95% confidence level, using a cut-off scale Lambda=1.5 TeV.Comment: 7 pages, 3 figures. Submitted to Phys. Rev.
Precision measurement of the top quark mass from dilepton events at CDF II
We report a measurement of the top quark mass, M_t, in the dilepton decay
channel of
using an integrated luminosity of 1.0 fb^{-1} of p\bar{p} collisions collected
with the CDF II detector. We apply a method that convolutes a leading-order
matrix element with detector resolution functions to form event-by-event
likelihoods; we have enhanced the leading-order description to describe the
effects of initial-state radiation. The joint likelihood is the product of the
likelihoods from 78 candidate events in this sample, which yields a measurement
of M_{t} = 164.5 \pm 3.9(\textrm{stat.}) \pm 3.9(\textrm{syst.})
\mathrm{GeV}/c^2, the most precise measurement of M_t in the dilepton channel.Comment: 7 pages, 2 figures, version includes changes made prior to
publication by journa
Cross Section Measurements of High- Dilepton Final-State Processes Using a Global Fitting Method
We present a new method for studying high- dilepton events
(, , ) and simultaneously
extracting the production cross sections of , , and p\bar{p} \to \ztt at a center-of-mass energy of TeV. We perform a likelihood fit to the dilepton data in a parameter
space defined by the missing transverse energy and the number of jets in the
event. Our results, which use of data recorded with the CDF
II detector at the Fermilab Tevatron Collider, are pb, pb, and
\sigma(\ztt) =291^{+50}_{-46} pb.Comment: 20 pages, 2 figures, to be submitted to PRD-R
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