Berend Wilkens

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We present ancient mitochondrial DNA analyses of 31 complete cytochrome b gene sequences from subfossil red deer remains from the Tyrrhenian islands (Corsica and Sardinia) and mainland Italy in a European-wide phylogeographic framework. Tyrrhenian and North African red deer, both going back to human introductions, were previously the only red deer to(More)
This paper describes an analysis of sub-jet multiplicities, which are expected to be sensitive to the properties of soft gluon radiation, in hadronic decays of the Z ~ Twoand three-jet event samples are selected using the k• jet clustering algorithm at a jet resolution scale Yl. The mean sub-jet multiplicity as a function of the sub-jet resolution, Yo, is(More)
The Cabauw Experimental Site for Atmospheric Research (CESAR) was established in 2002 as a consortium of eight Dutch institutes involved in atmospheric research [1]. The CESAR site is an atmospheric reference site of major importance in the European and medial atmospheric research networks. Observations at CESAR cover a wide spectrum of measurements and(More)
We have studied the reactions ?? ~ t +/~and yy--*r+ r by measuring the properties of events of the types e + e * e + e I ~ + l ~ and e + e ~ e + e z + z at e + e centre-of-mass energies between 88 and 94 GeV. The data sample corresponds to an integrated e+e luminosity of 40.4 p b 1 collected by the OPAL detector at LEP. The QED structure function F 2 is(More)
A search for the neutral Higgs bosons h ~ and A ~ predicted by the Minimal Supersymmetric Extension of the Standard Model (MSSM), has been performed by the OPAL Collaboration at LEP. The analysis was based on approximately 75 pb -1 of data taken at centre-of-mass energies in the vicinity of the Z ~ resonance. No Higgs boson signals have been detected.(More)
We have searched for unstable neutral and charged heavy leptons, N and L±, and for excited states of neutral and charged leptons, ν∗, e∗, μ∗ and τ∗, in e+e− collisions at centre-of-mass energies of 170 and 172 GeV using the OPAL detector at LEP. No evidence for their existence was found. From the analysis of charged-current decays of pair-produced unstable(More)
We report on a measurement of the ratio of the strong coupling constants es(Mzo) for various data samples with different quark flavour compositions obtained f rom e + e annihilation at LEP. We select events with muons, electrons, and D *• mesons f rom charm and bot tom decays, events with highly energetic K ~ mesons originating predominantly f rom strange(More)
The fractional partial width of the Z ~ to b quarks, Fb~/Fha a, has been measured by OPAL using an impact parameter technique. The method has been developed using 130 000 hadronic events collected by OPAL in 1990. We find: Fb~ 0.222 __ 0.007 (stat) _+ 0.008 (sys). if'had The measurement assumes the relative rates of the Z ~ to uds and c quarks given by the(More)
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