5 research outputs found
Bose-Einstein Correlations of Pion Wavepackets
A wavepacket model for a system of free pions, which takes into account the
full permutation symmetry of the wavefunction and which is suitable for any
phase space parametrization is developed. The properties of the resulting mixed
ensembles and the two-particle correlation function are discussed. A physical
interpretation of the chaoticity lambda as localizat of the pions in the source
is presented.
Two techniques to generate test-particles, which satisfy the probability
densities of the wavepacket state, are studied:
1. A Monte Carlo procedure in momentum space based on the standard Metropolis
technique.
2. A molecular dynamic procedure using Bohm's quantum theory of motion.
In order to reduce the numerical complexity, the separation of the
wavefunction into momentum space clusters is discussed. In this context th
influence of an unauthorized factorization of the state, i. e. the omissio of
interference terms, is investigated. It is shown that the correlation radius
remains almost uneffected, but the chaoticity parameter decreases
substantially. A similar effect is observed in systems with high multiplic
where the omission of higher order corrections in the analysis of two-part
correlations causes a reduction of the chaoticity and the radius.
The approximative treatment of the Coulomb interaction between pions and
source is investigated. The results suggest that Coulomb effects on the co
radii are not symmetric for pion pairs of different charges. For negative the
radius, integrated over the whole momentum spectrum, increases substan while
for positive pions the radius remains almost unchanged.Comment: 15 pages, 8 figures, 0.8 Mb, uses ljour2-macro, Submitted to Z. Phys.
A (1997
Extraction and recognition of tonal sounds produced by small cetaceans and identification of individuals
SIGLEAvailable from British Library Document Supply Centre-DSC:DX200125 / BLDSC - British Library Document Supply CentreGBUnited Kingdo