570 research outputs found
Integrability and Conformal Symmetry in the BCS model
The exactly solvable BCS Hamiltonian of superconductivity is considered from
several viewpoints: Richardson's ansatz, conformal field theory, integrable
inhomogenous vertex models and Chern-Simons theory.Comment: Latex with macros included, 12 pages, Proceedings of the NATO
Advanced Research Workshop on Statistical Field Theories, Como 18-23 June
2001. Editors: Andrea Cappelli and Giuseppe Mussardo. to be published by
Kluwer, Academic Publishers. Corrected some typos and further acknowledgment
Yang-Mills Solutions on Euclidean Schwarzschild Space
We show that the apparently periodic Charap-Duff Yang-Mills `instantons' in
time-compactified Euclidean Schwarzschild space are actually time independent.
For these solutions, the Yang-Mills potential is constant along the time
direction (no barrier) and therefore, there is no tunneling. We also
demonstrate that the solutions found to date are three dimensional monopoles
and dyons. We conjecture that there are no time-dependent solutions in the
Euclidean Schwarzschild background.Comment: 12 pages, references added, version to appear in PR
QED in a Strong External Magnetic Field: Beyond the Constant Mass Approximation
We solve the Schwinger-Dyson equations for QED in 2+1 or 3+1 dimensions in
the presence of a strong homogeneous external magnetic field. The magnetic
field is assumed strong enough, so that the lowest Landau level approximation
holds, but the usual assumption of a momentum-independent self-energy is not
made. In 2+1 dimensions, the scaling with logarithm changes to a square root
dependence on the magnetic field, but the most spectacular result takes place
in 3+1 dimensions, where the constant mass approximation turns out to be
unreliable and the (momentum-dependent) dynamical mass is larger by several
orders of magnitude compared to what has been found till now using the constant
mass approximation.Comment: 21 pages, 8 figures, plain latex, references adde
Knockout of proton-neutron pairs from O with electromagnetic probes
After recent improvements to the Pavia model of two-nucleon knockout from
O with electromagnetic probes the calculated cross sections are compared
to experimental data from such reactions. Comparison with data from a
measurement of the O(e,epn) reaction show much better agreement
between experiment and theory than was previously observed. In a comparison
with recent data from a measurement of the O(,pn) reaction the
model over-predicts the measured cross section at low missing momentum.Comment: 6 pages, 5 figure
Risk Categorization Using New American College of Cardiology/American Heart Association Guidelines for Cholesterol Management and Its Relation to Alirocumab Treatment Following Acute Coronary Syndromes
BACKGROUND: The 2018 US cholesterol management guidelines recommend
additional lipid-lowering therapies for secondary prevention in patients with lowdensity lipoprotein cholesterol ≥70 mg/dL or non−high-density lipoprotein cholesterol
≥100 mg/dL despite maximum tolerated statin therapy. Such patients are considered
at very high risk (VHR) based on a history of >1 major atherosclerotic cardiovascular
disease (ASCVD) event or a single ASCVD event and multiple high-risk conditions.
We investigated the association of US guideline-defined risk categories with the
occurrence of ischemic events after acute coronary syndrome and reduction of
those events by alirocumab, a PCSK9 (proprotein convertase subtilisin/kexin type 9)
inhibitor.
METHODS: In the ODYSSEY OUTCOMES trial (Evaluation of Cardiovascular
Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab),
patients with recent acute coronary syndrome and residual dyslipidemia despite
optimal statin therapy were randomly assigned to alirocumab or placebo. The primary
trial outcome (major adverse cardiovascular events, ie, coronary heart disease death,
nonfatal myocardial infarction, is
Differential Cross Section of DP-Elastic Scattering at Intermediate Energies
The deuteron-proton elastic scattering is studied in the multiple scattering
expansion formalism. The contributions of the one-nucleon-exchange, single- and
double scattering are taken into account. The Love and Franey parameterization
of the nucleon-nucleon -matrix is used, that gives an opportunity to include
the off-energy-shell effects into calculations. Differential cross sections are
considered at four energies, MeV. The obtained
results are compared with the experimental data
Measurement of the p-pbar -> Wgamma + X cross section at sqrt(s) = 1.96 TeV and WWgamma anomalous coupling limits
The WWgamma triple gauge boson coupling parameters are studied using p-pbar
-> l nu gamma + X (l = e,mu) events at sqrt(s) = 1.96 TeV. The data were
collected with the DO detector from an integrated luminosity of 162 pb^{-1}
delivered by the Fermilab Tevatron Collider. The cross section times branching
fraction for p-pbar -> W(gamma) + X -> l nu gamma + X with E_T^{gamma} > 8 GeV
and Delta R_{l gamma} > 0.7 is 14.8 +/- 1.6 (stat) +/- 1.0 (syst) +/- 1.0 (lum)
pb. The one-dimensional 95% confidence level limits on anomalous couplings are
-0.88 < Delta kappa_{gamma} < 0.96 and -0.20 < lambda_{gamma} < 0.20.Comment: Submitted to Phys. Rev. D Rapid Communication
Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt{s} = 1.96 TeV using Kinematic Characteristics of Lepton + Jets Events
We present a measurement of the top quark pair ttbar production cross section
in ppbar collisions at a center-of-mass energy of 1.96 TeV using 230 pb**{-1}
of data collected by the DO detector at the Fermilab Tevatron Collider. We
select events with one charged lepton (electron or muon), large missing
transverse energy, and at least four jets, and extract the ttbar content of the
sample based on the kinematic characteristics of the events. For a top quark
mass of 175 GeV, we measure sigma(ttbar) = 6.7 {+1.4-1.3} (stat) {+1.6- 1.1}
(syst) +/-0.4 (lumi) pb, in good agreement with the standard model prediction.Comment: submitted to Phys.Rev.Let
- …