54,224 research outputs found
A technique to eliminate false lock in PCM demodulation
One loop provides error signal which adjusts voltage controlled oscillator. Second loop multiplies input signal with generated in-phase signal. Both signals are integrated over bit period. First loop detects null which indicates lockup, and second loop emphasizes impact signal information
Phase shift keyed, pulse code modulated signal synchronizer
Signal is demodulated and synchronized by three loop circuits: ''Q'' loop uses quadrature signal to stabilize frequency; ''B'' loop acts on baseboard signal to stabilize phase; and decoding ''I'' loop acts on in-phase signal. Synchronizer may be used to eliminate false-lock
Pulse code modulated signal synchronizer
A bit synchronizer for a split phase PCM transmission is reported that includes three loop circuits which receive incoming phase coded PCM signals. In the first loop, called a Q-loop, a generated, phase coded, PCM signal is multiplied with the incoming signals, and the frequency and phase of the generated signal are nulled to that of the incoming subcarrier signal. In the second loop, called a B-loop, a circuit multiplies a generated signal with incoming signals to null the phase of the generated signal in a bit phase locked relationship to the incoming signal. In a third loop, called the I-loop, a phase coded PCM signal is multiplied with the incoming signals for decoding the bit information from the PCM signal. A counter means is used for timing of the generated signals and timing of sample intervals for each bit period
Hidden gauge structure and derivation of microcanonical ensemble theory of bosons from quantum principles
Microcanonical ensemble theory of bosons is derived from quantum mechanics by
making use of a hidden gauge structure. The relative phase interaction
associated with this gauge structure, described by the Pegg-Barnett formalism,
is shown to lead to perfect decoherence in the thermodynamics limit and the
principle of equal a priori probability, simultaneously.Comment: 10 page
Formation of \eta'(958)-mesic nuclei and axial U_A(1) anomaly at finite density
We discuss the possibility to produce the bound states of the
meson in nuclei theoretically. We calculate the formation cross sections of the
bound states with the Green function method for (,p) reaction
and discuss the experimental feasibility at photon facilities like SPring-8. We
conclude that we can expect to observe resonance peaks in (,p) spectra
for the formation of bound states and we can deduce new information on
properties at finite density. These observations are believed to be
essential to know the possible mass shift of and deduce new information
of the effective restoration of the chiral anomaly in the nuclear
medium.Comment: 4 pages, 3 figure
Studies of parton distributions at a neutrino factory
The determination of parton distribution functions in the nucleon and nuclei
is important for obtaining precise hadron-reaction cross sections, from which
any new exotic signature could be found. We show that a future neutrino factory
could provide important information on the parton distributions. First, a
recent effort concerning the parametrization of nuclear parton distributions is
explained. It suggests that the factory should be important for determining
unknown behavior of valence-quark distributions in nuclei at small . Second,
the facility could be used for understanding nucleon spin structure and isospin
violation in the parton distributions.Comment: 1+3 pages, LaTeX2e, elsart.cls, wrapfig.sty, 1 eps figure. Talk given
at the Third International Workshop on Neutrino Factories based on Muon
Storage Rings (NuFACT'01), May 24 - 30, 2001, Tsukuba, Japan. To be published
in proceedings. Email: [email protected], WWW:
http://hs.phys.saga-u.ac.j
Supersymmetric Particle Production at HERA
In the framework of the minimal supersymmetric standard model and the
-parity breaking model, we investigate various production processes of the
supersymmetric partner at HERA energies. Our emphasis is paid upon the scalar
top quark, the partner of top quark, characterized by its lighter mass than the
top quark and other scalar quarks in a model. We propose experimentally
feasible approaches to search for clean signals of the stop from either its
production or decay processes.Comment: 30 pages, LaTeX, 21 figures available upon reques
Precision Measurement of Orthopositronium Decay Rate Using SiO_2 Powder
The intrinsic decay rate of orthopositronium formed in powder
is measured using the direct correction method such that the time
dependence of the pick-off annihilation rate is precisely determined using high
energy-resolution germanium detectors. As a systematic test, two different
types of powder are used with consistent findings. The intrinsic
decay rate of orthopositronium is found to be , which is consistent with previous measurements using powder with about twice the accuracy. Results agree well with a recent
QED prediction, varying experimental standard
deviations from other measurements.Comment: 16 pages, 7 figures included. To be published in Physics Letters
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