Hunting the CKM weak phase with time-integrated Dalitz analyses of Bs -> K pi pi decays

We present a new technique to extract information on the Unitarity Triangle from the study of Bs -> K pi pi Dalitz plot. Using isospin symmetry and the possibility to access the decay amplitudes from Dalitz analyses, we propose a new strategy to extract the weak phase gamma from Bs to K pi pi.Comment: 2 pages. v2: Discussion of interference on Dalitz plot clarified. Bs -> K K pi channels removed. v3: Improved discussion of experimental aspects. Final version to appear in Phys. Lett.

CP violation in supersymmetric theories

We review the present status of CP violating problem in supersymmetric extensions of the standard model. We analyze the constraints imposed by the experimental limits of the electron, neutron, and mercury electric dipole moments on the supersymmetric CP phases and show that only the scenarios with flavour-off- diagonal CP violation remain attractive. These scenarios require hermitian Yukawa matrices which naturally arise in models with left-right symmetry or a SU(3) flavour symmetry. In this case, epsilon_K and epsilon'/epsilon can be saturated by a small non-universality of the soft scalar masses through the gluino and chargino contributions respectively. The model also predicts a strong correlation between A_{CP}(b-> s gamma) and the neutron electric dipole moment. In this framework, the standard model gives a the leading contribution to the CP asymmetry in B ->psi K_S decay, while the dominant chargino contribution to this asymmetry is < 0.2. Thus, no constraint is set on the non-universality of this model by the recent BaBar and Belle measureets.Comment: 34 pages, 10 figures. Invited review article for International Journal of Modern Physics

Theoretical status of epsilon'/epsilon

We review the theory of epsilon'/epsilon and present an updated phenomenological analysis using hadronic matrix elements from lattice QCD. The present status of the computation of epsilon'/epsilon, considering various approaches to the matrix-element evaluation, is critically discussed.Comment: 22 pages, 2 eps figures, based on the talks given by M.C. at "Les Rencontres de Physique de la Vallee d'Aoste", La Thuile (Italy), 27 February-4 March 2000 and by G.M. at the "XXXVth Rencontres de Moriond", Les Arcs 1800 (France), 11-18 March 200

NLO corrections to Delta F=2 effective Hamiltonians and SUSY contribution to FCNC

The most general QCD-NLO Anomalous-Dimension Matrix of all four-fermion dimension six Delta F=2 operators is presented. Two applications of this Anomalous-Dimension Matrix to the study of SUSY contribution to K- Kbar mixing are also discussed.Comment: 4 pages. Talk given at International Euroconference on Quantum Chromodynamics (QCD98), Montpellier, France, 2-8 july 1998. Submitted to Nucl. Phys. B (Proc. Suppl.

Opportunities From Precision Flavour Physics

The possible role of precision flavour physics, and particularly of B physics, in the next decade is briefly discussed. Few 2--3$\sigma$ deviations from the Standard Model found in present $B$ data are reviewed as potential forerunners of new physics signals to be looked for in next-generation experiments. The perspectives for theoretical calculations, in particular those based on lattice QCD, to match the expected progress in experimental precision are also discussed.Comment: 10 pages, 7 figures, proceedings of the 12th International Conference on B-Physics at Hadron Machines - BEAUTY 2009, September 07-12, 2009, Heidelberg, German

Status of the CKM matrix

An updated determination of the parameters of the Cabibbo-Kobayashi-Maskawa matrix is presented.Comment: 8 pages, 9 figures, uses espcrc2.sty. Talk given at the "7th Topical Seminar on the Legacy of LEP and SLC", 8-11 October 2001, Siena (Italy

Charming penguin and direct CP-violation in charmless B decays

In the study of two-body charmless B decays as a mean of looking for direct CP-violation and measuring the CKM mixing parameters in the Standard Model, the short-distance penguin contribution with its absorptive part generated by charm quark loop seems capable of producing sufficient $B \to K\pi$ decays rates, as obtained in factorization and QCD-improved factorization models. However there are also long-distance charming penguin contributions which could give rise to a strong phase due to the rescattering $D^{*}D^{*}_{s} \to K\pi$ etc. In this talk, I would like to discuss recent works on the charming penguin contribution as a different approach to the calculation of these contributions in two-body charmless B decays. We find that the charming penguin contribution is significant for $B\to K\pi$ decays and, together with the tree and penguin terms, produces large branching ratios in agreement with data, though the analysis is affected by large theoretical uncertainties. The absorptive part due to the charmed meson intermediate states is found to produce large CP asymmetries for $B \to K\pi, \pi\pi$ decays.Comment: Talk given at the QCD Euroconference 2002, Montpellier 2-9 July 2002, LaTex, 7 pages, Misprint in the Tables correcte

The Chromomagnetic Dipole Operator and the B Semileptonic Branching Ratio

We consider the possibility of having a large branching ratio for the decay $b\to s g$ coming from an enhanced Wilson coefficient of the chromomagnetic dipole operator. We show that values of $BR(b\to s g)$ up to $\sim 10\%$ or more are compatible with the constraints coming from the CLEO experimental results on $BR(B\to X_s\gamma)$ and $BR(B\to X_s\phi)$. Such large values can reconcile the predictions of both the semileptonic branching ratio and the charm counting with the present experimental results. We also discuss a supersymmetric model with gluino-mediated flavour violations, which can account for such large values of $BR(b\to s g)$.Comment: 19 pages, 3 eps figures included, replacement with minor change