5,827 research outputs found
Bose-Einstein and Other Correlations in Hadronic Z Decay
In hadronic Z decays, Bose-Einstein correlations in neutral pion pairs are
compared to those in identical charged pion pairs. Bose-Einstein correlations
are also measured in triplets of identical charged pions, and comparison with
those in pairs of pions indicates that pion production is completely
incoherent. Further, factorial cumulants are used to compare correlations among
like-sign as well as among all particles with those of several Monte Carlo
models.Comment: 4 pages, 3 figures, Rencontres de Moriond - QCD 200
QCD at LEP
Several preliminary QCD results from e+e- interactions at LEP are reported.
These include studies of event shape variables, which are used to determine
alpha_s and for studies of the validity of power corrections. Further, a study
of color reconnection effects in 3-jet Z decays is reported.Comment: Invited talk at XXXIII Intl. Symposium on Multiparticle Dynamics,
Cracow, Poland, 5-11 Sept., 2003. To appear in the proceedings in Acta
Physica Polonic
Bose-Einstein correlations in e+e- annihilation and e+e- ==> W+W-
Results on Bose-Einstein correlations in e+e- ==> hadrons are reviewed.Comment: Talk given at Fourth Workshop on Particle Correlations and
Femtoscopy, Kromeriz, Czech Republic, August 15-17, 2005. A shortened version
will appear in the proceeding
New Bose-Einstein Results from L3
In hadronic Z decays, we compare Bose-Einstein correlations in \Pgpz pairs
with those in identical charged pion pairs. We also measure Bose-Einstein
correlations in triplets of identical charged pions. From the first study, the
source radius is found to be smaller for \Pgpz-\Pgpz than for \Pgppm-\Pgppm, as
would be expected, e.g., in a string model. However, the second study shows
that the data are consistent with the pion production being completely
incoherent. Both studies use data collected by the L3 collaboration at LEP.Comment: 4 pages, 3 figures in eps, talk given at XXXI International Symposium
on Multiparticle Dynamics, Sept 1-7, 2001, Datong China. see
http://ismd31.ccnu.edu.cn
Measurement of the Scaling Property of Factorial Moments in Hadronic Z Decay
Both three- and one-dimensional studies of local multiplicity fluctuations in
hadronic Z decay are performed using data of the L3 experiment at LEP. The
normalized factorial moments in three dimensions exhibit power-law scaling,
indicating that the fluctuations are isotropic, which correspends to a
self-similar fractal. A detailed study of the corresponding one-dimensional
moments confirms this conclusion. However, two-jet subsamples have anisotropic
fluctuations, correspending to a self-affine fractal. These features are, at
least qualitatively, reproduced by the Monte Carlo models \JETSET and \HERWIG.Comment: 4 pages, 4 figures in eps, talk given at XXXI International Symposium
on Multiparticle Dynamics, Sept 1-7, 2001, Datong China. see
http://ismd31.ccnu.edu.cn
The oxidation and sublimation of graphite in simulated re-entry environments
Graphite oxidation and sublimation in simulated reentry environment
The time evolution of marginally trapped surfaces
In previous work we have shown the existence of a dynamical horizon or
marginally trapped tube (MOTT) containing a given strictly stable marginally
outer trapped surface (MOTS). In this paper we show some results on the global
behavior of MOTTs assuming the null energy condition. In particular we show
that MOTSs persist in the sense that every Cauchy surface in the future of a
given Cauchy surface containing a MOTS also must contain a MOTS. We describe a
situation where the evolving outermost MOTS must jump during the coalescence of
two seperate MOTSs. We furthermore characterize the behavior of MOTSs in the
case that the principal eigenvalue vanishes under a genericity assumption. This
leads to a regularity result for the tube of outermost MOTSs under the
genericity assumption. This tube is then smooth up to finitely many jump times.
Finally we discuss the relation of MOTSs to singularities of a space-time.Comment: 21 pages. This revision corrects some typos and contains more
detailed proofs than the original versio
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