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This report presents the capabilities of the CMS experiment to explore the rich heavy-ion physics programme offered by the CERN Large Hadron Collider (LHC). The collisions of lead nuclei at energies √ s N N = 5.5 TeV, will probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research is to study the fundamental theory of the strong interaction -Quantum Chromodynamics (QCD) -in extreme conditions of temperature, density and parton momentum fraction (low-x).This report covers in detail the potential of CMS to carry out a series of representative Pb-Pb measurements. These include "bulk" observables, (charged hadron multiplicity, low p T inclusive hadron identified spectra and elliptic flow) which provide information on the collective properties of the system, as well as perturbative probes such as quarkonia, heavy-quarks, jets and high p T hadrons which yield "tomographic" information of the hottest and densest phases of the reaction.

The longitudinal polarization, the transverse polarization, and the forward-backward asymmetry of Λ baryons, have been measured using a sample of 4.34 million hadronic Z 0 decays collected with the OPAL detector at LEP between 1990 and 1995. These results are important as an aid to the understanding of hadronization mechanisms. Significant longitudinal polarization has been observed at intermediate and high momentum. For x E (≡ 2E Λ / √ s) > 0.3, the longitudinal polarization has been measured to be −32.9 ± 5.5 (stat) ± 5.2 (syst)%. We have observed no transverse polarization. A significant forward-backward asymmetry has been measured and can be described by a JETSET model.

We h a v e searched for lepton avour violating Z 0 !e, Z 0 ! e and Z 0 ! decays in a sample of 4:0 10 6 visible Z 0 decays collected with the OPAL detector at LEP during 1991 to 1994. No candidates are found for Z 0 !e. The samples of selected Z 0 !e and Z 0 ! candidates are consistent with the expected background. The following limits are set at 95% condence level:BR(Z 0 ! e) < 1:7 10 6