91,834 research outputs found
Laboratory requirements for in-situ and remote sensing of suspended material
Recommendations for laboratory and in-situ measurements required for remote sensing of suspended material are presented. This study investigates the properties of the suspended materials, factors influencing the upwelling radiance, and the various types of remote sensing techniques. Calibration and correlation procedures are given to obtain the accuracy necessary to quantify the suspended materials by remote sensing. In addition, the report presents a survey of the national need for sediment data, the agencies that deal with and require the data of suspended sediment, and a summary of some recent findings of sediment measurements
Possibly New Charmed Baryon States from Decay
We examine the invariant mass spectrum of in decay measured by BABAR and find that through the 2-step processes of
, where denotes a
charmed baryon state, some of the peaks can be identified with the established
, and . Moreover, in
order to account for the measured spectrum, it is necessary to introduce a new
charmed baryon resonance with MeV.Comment: 8 pages, 1 figure, title changed and discussions updated, version
accepted for publication in Phys. Rev.
Long-term X-ray emission from Swift J1644+57
The X-ray emission from Swift J1644+57 is not steadily decreasing instead it
shows multiple pulses with declining amplitudes. We model the pulses as reverse
shocks from collisions between the late ejected shells and the externally
shocked material, which is decelerated while sweeping the ambient medium. The
peak of each pulse is taken as the maximum emission of each reverse shock. With
a proper set of parameters, the envelope of peaks in the light curve as well as
the spectrum can be modelled nicely.Comment: 6 pages, 2 figures, accepted for publication in MNRA
Interacting Individuals Leading to Zipf's Law
We present a general approach to explain the Zipf's law of city distribution.
If the simplest interaction (pairwise) is assumed, individuals tend to form
cities in agreement with the well-known statisticsComment: 4 pages 2 figure
Inclusive Decays of Bottom Hadrons in New Formulation of Heavy Quark Effective Field Theory
We apply the new formulation of heavy quark effective field theory (HQEFT) to
the inclusive decays of bottom hadrons. The long-term ambiguity of using heavy
quark mass or heavy hadron mass for inclusive decays is clarified within the
framework of the new formulation of HQEFT. The order corrections are
absent and contributions from terms are calculated in detail. This
enables us to reliably extract the important CKM matrix element from
the inclusive semileptonic decay rates. The resulting lifetime ratios
and are found to well agree
with the experimental data. We also calculate in detail the inclusive
semileptonic branching ratios and the ratios of the and decay
rates as well as the charm countings in the , and
systems. For decays, all the observables are found to be consistent with
the experimental data. More precise data for the decays and further
experimental measurements for the and systems will be very
useful for testing the framework of new formulation of HQEFT at the level of
higher order corrections.Comment: 20 pages, RevTex, 8 figures, 3 tables, revised version with `dressed
heavy quark' being addressed, to be published in Int. J. Mod. Phys.
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