[en] Direct CP-violating effects in the neutral kaon system result in violations of certain Bell-like inequalities. The new experimental results on the determination of the phenomenological parameter ε' allow to dismiss a large class of ''hidden variable'' alternatives to quantum mechanics. (orig.)

[en] Measurements of CP asymmetries in B decays will soon be made at B factories and hadron machines. In light of this, we review and update the profile of the CKM unitarity triangle and the resulting CP asymmetries in B decays. This is done both in the standard model and in several variants of the minimal supersymmetric standard model (MSSM), which are characterized by a single phase in the quark flavour mixing matrix. After imposing present constraints on the parameters of these models, the predicted ranges of sin 2β in the standard model and in the MSSM are found to be similar. However, these theories may be distinguished by future precise measurements of the other two CP-violating phases α and γ. (orig.)

[en] The decays B_d → π⁺π^- and B_s → K⁺K^- provide an interesting strategy to extract the CKM angle γ at ''second-generation'' B-physics experiments of the LHC era. A variant for ''first-generation'' experiments can be obtained, if B_s → K⁺K^- is replaced by B_d → π^-+K^±. We show that the most recent experimental results for the CP-averaged B_d → π⁺π^- and B_d → π^-+K^± branching ratios imply a rather restricted range for the corresponding penguin parameters, and upper bounds on the direct CP asymmetries A_CP^dir(B_d → π⁺π^-) and A_CP^dir(B_d → π^-+K^±). Moreover, we point out that interesting constraints on γ can be obtained from the CP-averaged B_d → π⁺π^- and B_d → π^-+K^± branching ratios, if in addition mixing-induced CP violation in the former decay is measured, and the B_d⁰-B_d⁰ mixing phase is fixed through B_d → J/ψK_s. An extraction of γ becomes possible, if furthermore direct CP violation in B_d → π⁺π^- or B_d → π^-+K^± is observed. (orig.)

[en] The chargino anti χ_1.2^± system can be reconstructed completely in e⁺e^- collisions. By measuring the total cross sections and the asymmetries with polarized beams in e⁺e^- → anti χ_i⁺ anti χ_j^- [i,j = 1,2], the chargino masses and the gaugino-higgsino mixing angles of these states can be determined very accurately. If only the lightest charginos anti χ₁^± are kinematically accessible, transverse beam polarization is needed to determine the mixing angles unambiguously. From these observables the fundamental SUSY parameters can be derived: the SU(2) gaugino mass M₂, the modulus and the cosine of the CP-violating phase of the higgsino mass parameter μ, and tan β = v₂/v₁, the ratio of the vacuum expectation values of the two neutral Higgs doublet fields. [The remaining two-fold ambiguity of the phase can be resolved by measuring the normal polarization of the charginos.] (orig.)

[en] We analyse CP-violating effects in Z→4 jet decays, assuming the presence of a CP-violating effective triple gluon coupling. We discuss the influence of this coupling on the decay width. Furthermore, we analyse different CP-odd observables and propose strategies of a direct search for such a CP-violating GGG coupling. The present data of LEP 1 should give significant information on the coupling. (orig.)

[en] The lifetimes of the B⁺ and B⁰ mesons, and their ratio, have been measured in the OPAL experiment using 2.4 million hadronic Z⁰ decays recorded at LEP. Z⁰ →bb decays were tagged using displaced secondary vertices and high momentum electrons and muons. The lifetimes were then measured using well-reconstructrd charged and neutral secondary vertices selected in this tagged data sample. The results are τ_B⁺=1.643±0.037±0.025 ps, τ_B⁰=1.523±0.057±0.053 ps, τ_B⁺/τ_B⁰=1.079±0.064±0.041, where in each case the first error is statistical and the second systematic. A larger data sample of 3.1 million hadronic Z⁰ decays has been used for CP and CPT violating effects by comparison of inclusive b and anti b hadron decays. No evidence for such effects is seen. The CP violation parameter Re(ε_B) is measured to be Re(ε _B)=0.001±0.014±0.003 and the fractional difference between b and anti b hadron lifetimes is measured to be (Δτ/τ)_b≡(τ(b-hadron)-τ(anti b-hadron))/τ(average)=0.001±0.012±0.008. (orig.)

[en] Non-leptonic B_s decays into CP eigenstates that are caused by b → ccs quark-level transitions, such as B_s → D_s⁺D_s^-, J/ψη^(') or J/ψφ, provide a powerful tool to search for ''new physics'', as the CP-violating effects in these modes are tiny in the standard model. We explore these effects for a particular scenario of new physics, the left-right-symmetric model with spontaneous CP violation. In our analysis, we take into account all presently available experimental constraints on the parameters of this model, i.e. those implied by K- and B-decay observables; we find that CP asymmetries as large as O(40%) may arise in the B_s channels, whereas the left-right-symmetric model favours a small CP asymmetry in the ''gold-plated'' mode B_d → J/ψK_S. Such a pattern would be in favour of B-physics experiments at hadron machines, where the B_s modes are very accessible. (orig.)

[en] In most supersymmetric theories charginos, χ_1,2^±, belong to the class of the lightest supersymmetric particles. The chargino system can be reconstructed completely in e⁺e^- collider experiments: e⁺e^- → χ_i⁺χ_j^- [i,j=1,2]. By measuring the total cross sections and the asymmetries with polarized beams, the chargino masses and the gaugino-higgsino mixing angles of these states can be determined accurately. If only the lightest charginos χ₁^± are kinematically accessible in a first phase of the machine, transverse beam polarization or the measurement of chargino polarization in the final state is needed to determine the mixing angles. From these observables the fundamental SUSY parameters can be derived: the SU(2) gaugino mass M₂, the modulus and the cosine of the CP-violating phase of the higgsino mass parameter μ, and tan β=υ₂/υ₁, the ratio of the vacuum expectation values of the two neutral Higgs doublet fields. The remaining two-fold ambiguity of the phase can be resolved by measuring the normal polarization of the charginos. Sum rules of the cross sections can be exploited to investigate the closure of the two-chargino system. (orig.)