20,474 research outputs found
User's guide to SFTRAN/1100
Extensions and improvements were made to SFTRAN, a structured programming language. This language was implemented as a precompiler that translates from SFTRAN to FORTRAN. It was available to batch and conversational users of the UNIVAC 1100 computer system. The SFTRAN language and its use are described. In addition, conversational time-sharing system command subroutines were implemented that eliminated the complications of dealing with extra files and processing steps that the use of a precompiler would otherwise require. These command subroutines are reported, and their use is illustrated by examples
User's guide for SFTRAN/360
Extension and improvements made to SFTRAN, a structured-programming language are discussed. This improved language is implemented as a precompiler that translates from SFTRAN to FORTRAN. The SFTRAN language and its use are described. Time-Sharing System (TSS) command procedures were implemented that eliminate the complications of dealing with extra files and processing steps which the use of a precompiler would otherwise require. These command procedures are described and their use is illustrated by examples
Semi-inclusive charged-current neutrino-nucleus reactions
The general, universal formalism for semi-inclusive charged-current
(anti)neutrino-nucleus reactions is given for studies of any hadronic system,
namely, either nuclei or the nucleon itself. The detailed developments are
presented with the former in mind and are further specialized to cases where
the final-state charged lepton and an ejected nucleon are presumed to be
detected. General kinematics for such processes are summarized and then
explicit expressions are developed for the leptonic and hadronic tensors
involved and for the corresponding responses according to the usual charge,
longitudinal and transverse projections, keeping finite the masses of all
particles involved. In the case of the hadronic responses, general symmetry
principles are invoked to determine which contributions can occur. Finally, the
general leptonic-hadronic tensor contraction is given as well as the cross
section for the process
Coincidence charged-current neutrino-induced deuteron disintegration
Deuteron disintegration by charged-current neutrino (CC) scattering
offers the possibility to determine the energy of the incident neutrino by
measuring in coincidence two of the three resulting particles: a charged lepton
(usually a muon) and two protons, where we show that this channel can be
isolated from all other, for instance, from those with a pion in the final
state. We discuss the kinematics of the process for several detection
scenarios, both in terms of kinematic variables that are natural from a
theoretical point of view and others that are better matched to experimental
situations. The deuteron structure is obtained from a relativistic model
(involving an approximation to the Bethe-Salpeter equation) as an extension of
a previous, well-tested model used in deuteron electrodisintegration. We
provide inclusive and coincidence (semi-inclusive) cross sections for a variety
of kinematic conditions, using the plane-wave impulse approximation,
introducing final-state hadronic exchange terms (plane-wave Born approximation)
and final-state hadronic interactions (distorted-wave Born approximation).Comment: 31 pages, 14 figure
The design of an automated verification of redundant systems
Handbook describes design processes, presents design considerations and techniques, gives tutorial material on implementation and methodology, shows design aids, illustrates use of design aids and application samples, and identifies general practices to be adhered to or avoided
Quantum measurement and decoherence
Distribution functions defined in accord with the quantum theory of
measurement are combined with results obtained from the quantum Langevin
equation to discuss decoherence in quantum Brownian motion. Closed form
expressions for wave packet spreading and the attenuation of coherence of a
pair of wave packets are obtained. The results are exact within the context of
linear passive dissipation. It is shown that, contrary to widely accepted
current belief, decoherence can occur at high temperature in the absence of
dissipation. Expressions for the decoherence time with and without dissipation
are obtained that differ from those appearing in earlier discussions
Cosmological and Black Hole Horizon Fluctuations
The quantum fluctuations of horizons in Robertson-Walker universes and in the
Schwarzschild spacetime are discussed. The source of the metric fluctuations is
taken to be quantum linear perturbations of the gravitational field. Lightcone
fluctuations arise when the retarded Green's function for a massless field is
averaged over these metric fluctuations. This averaging replaces the
delta-function on the classical lightcone with a Gaussian function, the width
of which is a measure of the scale of the lightcone fluctuations. Horizon
fluctuations are taken to be measured in the frame of a geodesic observer
falling through the horizon. In the case of an expanding universe, this is a
comoving observer either entering or leaving the horizon of another observer.
In the black hole case, we take this observer to be one who falls freely from
rest at infinity. We find that cosmological horizon fluctuations are typically
characterized by the Planck length. However, black hole horizon fluctuations in
this model are much smaller than Planck dimensions for black holes whose mass
exceeds the Planck mass. Furthermore, we find black hole horizon fluctuations
which are sufficiently small as not to invalidate the semiclassical derivation
of the Hawking process.Comment: 22 pages, Latex, 4 figures, uses eps
A Third Planet Orbiting HIP 14810
We present new precision radial velocities and a three-planet Keplerian orbit
fit for the V = 8.5, G5 V star HIP 14810. We began observing this star at Keck
Observatory as part of the N2K Planet Search Project. Wright et al. (2007)
announced the inner two planets to this system, and subsequent observations
have revealed the outer planet planet and the proper orbital solution for the
middle planet. The planets have minimum masses of 3.9, 1.3, and 0.6 M_Jup and
orbital periods of 6.67, 147.7, and 952 d, respectively. We have numerically
integrated the family of orbital solutions consistent with the data and find
that they are stable for at least 10^6 yr. Our photometric search shows that
the inner planet does not transit.Comment: ApJL, accepte
- …