74 research outputs found
Updated precision measurement of the average lifetime of B hadrons
The measurement of the average lifetime of B hadrons using inclusively reconstructed secondary vertices has been updated using both an improved processing of previous data and additional statistics from new data. This has reduced the statistical and systematic uncertainties and gives \tau_{\mathrm{B}} = 1.582 \pm 0.011\ \mathrm{(stat.)} \pm 0.027\ \mathrm{(syst.)}\ \mathrm{ps.} Combining this result with the previous result based on charged particle impact parameter distributions yields \tau_{\mathrm{B}} = 1.575 \pm 0.010\ \mathrm{(stat.)} \pm 0.026\ \mathrm{(syst.)}\ \mathrm{ps.
Inclusive measurements of the K+- and p / anti-p production in hadronic Z0 decays
This analysis, based on a sample of 170000 hadronic Z0 decays, provides a measurement of the K± and p/pÌ differential cross sections which is compared to string- and cluster fragmentation models. The total multiplicities for K± and p/pÌ per hadronic event were found to be: NK = 2.26 ± 0.18 and Np = 1.07 ± 0.14. The positions Ο* of the maxima of the differential cross sections as a function of Ο = In(1/xp) for K± and p/pÌ were determined to be 2.63 ± 0.07 and 2.96 ± 0.16 respectively. A comparison of the Ο* values for various identified particles measured at LEP with the prediction of the Modified Leading Logarithm Approximation with Local Parton Hadron Duality model has been performed. The measured Ο* position as a function of the hadron mass, after corrections due to particle decays, is in agreement with the model calculation.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe
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