260 research outputs found
Lunar lander mass spectrometer Final report
Sputter ion source for lunar lander mass spectromete
Mass spectrometer analysis of solid materials with the ion-microprobe sputter source
Sputter ion source mass spectrometer for analysis of solid material
Towards a fully self-consistent spectral function of the nucleon in nuclear matter
We present a calculation of nuclear matter which goes beyond the usual
quasi-particle approximation in that it includes part of the off-shell
dependence of the self-energy in the self-consistent solution of the
single-particle spectrum. The spectral function is separated in contributions
for energies above and below the chemical potential. For holes we approximate
the spectral function for energies below the chemical potential by a
-function at the quasi-particle peak and retain the standard form for
energies above the chemical potential. For particles a similar procedure is
followed. The approximated spectral function is consistently used at all levels
of the calculation. Results for a model calculation are presented, the main
conclusion is that although several observables are affected by the inclusion
of the continuum contributions the physical consistency of the model does not
improve with the improved self-consistency of the solution method. This in
contrast to expectations based on the crucial role of self-consistency in the
proofs of conservation laws.Comment: 26 pages Revtex with 4 figures, submitted to Phys. Rev.
Thermal Evolution of Compact Stars
A collection of modern, field-theoretical equations of state is applied to
the investigation of cooling properties of compact stars. These comprise
neutron stars as well as hypothetical strange matter stars, made up of
absolutely stable 3-flavor strange quark matter. Various uncertainties in the
behavior of matter at supernuclear densities, e.g., hyperonic degrees of
freedom, behavior of coupling strengths in matter, pion and meson condensation,
superfluidity, transition to quark matter, absolute stability of strange quark
matter, and last but not least the many-body technique itself are tested
against the body of observed cooling data.Comment: 41 pages, revised versio
Relativistic Brueckner-Hartree-Fock calculations with explicit intermediate negative energy states
In a relativistic Brueckner-Hartree-Fock calculation we include explicit
negative-energy states in the two-body propagator. This is achieved by using
the Gross spectator-equation, modified by medium effects. Qualitatively our
results compare well with other RBHF calculations. In some details significant
differences occur, e.g, our equation of state is stiffer and the momentum
dependence of the self-energy components is stronger than found in a reference
calculation without intermediate negative energy states.Comment: 13 pages Revtex, 5 figures included seperatel
Particle-Antiparticle Mixing, epsilon_K, Delta Gamma_q, A_SL^q, A_CP(B_d -> psi K_S), A_CP(B_s -> psi phi) and B -> X_{s,d} gamma in the Littlest Higgs Model with T-Parity
We calculate a number of observables related to particle-antiparticle mixing
in the Littlest Higgs model with T-parity (LHT). The resulting effective
Hamiltonian for Delta F=2 transitions agrees with the one of Hubisz et al., but
our phenomenological analysis goes far beyond the one of these authors. In
particular, we point out that the presence of mirror fermions with new flavour
and CP-violating interactions allows to remove the possible Standard Model (SM)
discrepancy between the CP asymmetry S_{psi K_S} and large values of |V_ub| and
to obtain for the mass difference Delta M_s < (Delta M_s)_SM as suggested by
the recent result by the CDF collaboration. We also identify a scenario in
which simultaneously significant enhancements of the CP asymmetries S_{phi psi}
and A_SL^q relative to the SM are possible, while satisfying all existing
constraints, in particular from the B -> X_s gamma decay and A_CP(B -> X_s
gamma) that are presented in the LHT model here for the first time. In another
scenario the second, non-SM, value for the angle gamma=-(109+-6) from tree
level decays, although unlikely, can be made consistent with all existing data
with the help of mirror fermions. We present a number of correlations between
the observables in question and study the implications of our results for the
mass spectrum and the weak mixing matrix of mirror fermions. In the most
interesting scenarios, the latter one turns out to have a hierarchical
structure that differs significantly from the CKM one.Comment: 51 pages, 20 figures, 1 table. Extended discussion of the phases in
the new mixing matrix V_Hd, some references added or updated, conclusions
unchanged. Final version published in JHE
The Discovery Potential of a Super B Factory
The Proceedings of the 2003 SLAC Workshops on flavor physics with a high
luminosity asymmetric e+e- collider. The sensitivity of flavor physics to
physics beyond the Standard Model is addressed in detail, in the context of the
improvement of experimental measurements and theoretical calculations.Comment: 476 pages. Printed copies may be obtained by request to
[email protected] . arXiv admin note: v2 appears to be identical to v
Electrocardiographic diagnosis of left ventricular hypertrophy in aortic valve disease: evaluation of ECG criteria by cardiovascular magnetic resonance
<p>Abstract</p> <p>Background</p> <p>Left ventricular hypertrophy (LVH) is a hallmark of chronic pressure or volume overload of the left ventricle and is associated with risk of cardiovascular morbidity and mortality. The purpose was to evaluate different electrocardiographic criteria for LVH as determined by cardiovascular magnetic resonance (CMR). Additionally, the effects of concentric and eccentric LVH on depolarization and repolarization were assessed.</p> <p>Methods</p> <p>120 patients with aortic valve disease and 30 healthy volunteers were analysed. As ECG criteria for LVH, we assessed the Sokolow-Lyon voltage/product, Gubner-Ungerleider voltage, Cornell voltage/product, Perugia-score and Romhilt-Estes score.</p> <p>Results</p> <p>All ECG criteria demonstrated a significant correlation with LV mass and chamber size. The highest predictive values were achieved by the Romhilt-Estes score 4 points with a sensitivity of 86% and specificity of 81%. There was no difference in all ECG criteria between concentric and eccentric LVH. However, the intrinsicoid deflection (V6 37 ± 1.0 ms vs. 43 ± 1.6 ms, p < 0.05) was shorter in concentric LVH than in eccentric LVH and amplitudes of ST-segment (V5 -0.06 ± 0.01 vs. -0.02 ± 0.01) and T-wave (V5 -0.03 ± 0.04 vs. 0.18 ± 0.05) in the anterolateral leads (p < 0.05) were deeper.</p> <p>Conclusion</p> <p>By calibration with CMR, a wide range of predictive values was found for the various ECG criteria for LVH with the most favourable results for the Romhilt-Estes score. As electrocardiographic correlate for concentric LVH as compared with eccentric LVH, a shorter intrinsicoid deflection and a significant ST-segment and T-wave depression in the anterolateral leads was noted.</p
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