ar X iv : h ep - p h / 95 06 25 4 v 1 7 J un 1 99 5 Effects of the U A ( 1 ) Anomaly on η → 2 γ Decay

ar X iv : h ep - p h / 95 06 25 9 v 1 7 J un 1 99 5 CERN – TH / 95 – 83 hep - ph / 9506259 May 1995 MULTIPLE HARD

ar X iv : h ep - p h / 95 06 25 0 v 1 6 J un 1 99 5 CERN - TH / 95 - 121 Jet Physics in Deeply Inelastic Scattering at HERA ∗

We give an overview of jet physics in deeply inelastic scattering at HERA. The problem of jet definitions, the scale dependence of jet cross sections and some applications are discussed.

ar X iv : h ep - p h / 99 06 26 9 v 1 6 J un 1 99 9 UK

An isospin analysis of B → ππ decays yields sin 2α, where α is the usual CKM angle α ≡ arg[−V td V * tb /(V ud V * ub)] without hadronic uncertainty if isospin is a perfect symmetry. Yet isospin symmetry is broken not only by electroweak effects but also by the u and d quark mass difference — the latter drives π 0 − η, η ′ mixing and converts the isospin-perfect triangle relation between the B ...

ar X iv : h ep - p h / 96 06 23 3 v 1 4 J un 1 99 6 Precision Electroweak Constraints on Top - Color Assisted

Using precision electroweak data, we put limits on " natural " top-color assisted technicolor models. Generically the new U (1) gauge bosons in these models must have masses larger than roughly 2 TeV, although in certain (seemingly unrealistic) models the bound can be much lower.

ar X iv : h ep - p h / 95 10 33 7 v 1 1 8 O ct 1 99 5 BARI - TH / 95 - 217 Υ ( 4 S ) →

We give an estimate of the C-even B 0 ¯ B 0 background coming from the radia-tive decay Υ(4S) → B 0 ¯ B 0 γ at B-factories. Our result B(Υ(4S) → B 0 ¯ B 0 γ) ≃ 3× 10 −9 shows that such background could be safely neglected in the analyses of CP violating effects.