0000000000915823
AUTHOR
H Bertelsen
A Study of Bose-Einstein Correlations In e+e- Annihilation At 91 Gev
This paper describes a study of Bose-Einstein correlations made using the ALEPH detector at LEP. The correlations are found to enhance the two particle differential cross section for pairs of identical pions by a factor which can be roughly parametrized by R(Q) = 1 + lambda exp(-Q2-sigma(2)), where Q is the difference in the 3-momenta of the two pions in their centre of mass frame, lambda = 0.51 +/- 0.04 +/- 0.11 and sigma = 3.3 +/- 0.2 +/- 0.8 GeV-1, which corresponds to a source size of 0.65 +/- 0.04 +/- 0.16 fm. The large systematic errors on these results reflect their strong dependence on the choice of the reference sample used in the analysis. This problem is believed to occur primari…
ALICE: Physics performance report, volume II
ALICE is a general-purpose heavy-ion experiment designed to study the physics of strongly interacting matter and the quark-gluon plasma in nucleus-nucleus collisions at the LHC. It currently involves more than 900 physicists and senior engineers, from both the nuclear and high-energy physics sectors, from over 90 institutions in about 30 countries. The ALICE detector is designed to cope with the highest particle multiplicities above those anticipated for Pb-Pb collisions (dN(ch)/dy up to 8000) and it will be operational at the start-up of the LHC. In addition to heavy systems, the ALICE Collaboration will study collisions of lower-mass ions, which are a means of varying the energy density, …
MEASUREMENT OF TAU BRANCHING RATIOS
著者人数：112名
Measurement of the charged particle multiplicity distribution in hadronic Z decays
The charged particle multiplicity distribution of hadronic Z decays was measured on the peak of the Z resonance using the ALEPH detector at LEP. Using a model independent unfolding procedure the distribution was found to have a mean = 20.85 +/- 0.24 and a dispersion D = 6.34 +/- 0.12. Comparison with lower energy data supports the KNO scaling hypothesis in the energy range square-root s = 29-91.25 GeV. At square-root s = 91.25 GeV the shape of the multiplicity distribution is well described by a log-normal distribution, as predicted from a cascading model for multi-particle production. The same model also successfully describes the energy dependence of the mean and width of the multiplicity…