Lepton flavour violating processes in an S3-invariant extension of the SM
A variety of lepton flavour violating effects related to neutrino oscillations and mixings will be systematically discussed in the framework of a minimal S3-invariant extension of the Standard Model. After a brief review of some results on neutrino masses and mixings, we will give explicit analytical expressions for the matrices of the Yukawa couplings and the results of a computation of the branching ratios of some selected flavour-changing neutral current (FCNC) processes, as well as, the contribution of the exchange of neutral flavour-changing scalars to the anomaly of the magnetic moment of the muon, in terms of the masses of the charged leptons and the neutral Higgs bosons. It will also be shown that the S3 × Z2 flavour symmetry and the strong mass hierarchy of the charged leptons strongly suppress the FCNC processes in the leptonic sector and give a nearly tri-bimaximal neutrino mixing matrix. The contribution of the FCNCs to the anomaly of the magnetic moment of the muon is small but non-negligible.

title: Finite unification at all-loops

title: Finite GUTs within conventional N=1 gauge theories
abstract: Finite Unified Theories (FUTs) are conventional N=1 supersymmetric Grand Unified Theories, which can be made all-loop finite, both in the dimensionless (gauge and Yukawa couplings) and dimensionful (soft supersymmetry breaking terms) sectors. This remarkable property leads to a drastic reduction in the number of free parameters, which in turn leads to an accurate prediction of the top quark mass in the dimensionless sector, and predictions for the Higgs boson mass and the s-spectrum in the dimensionful sector. Among the characteristics of the latter ones are: 1) The lightest Higgs boson mass is predicted to be in the window 120–130 GeV, in case the LSP is neutralino, while in case the LSP is the τ (which can be consistently accommodated in presence of bilinear R-parity violating terms) it can be as light as 111 GeV. 2) The s-spectrum starts above several hundreds of GeV.

title: Conditions for vacuum stability in an S3 extension of the Standard Model
abstract: In this work we study the Higgs sector in the minimal S3 extension of the Standard Model. The S3 extended Standard Model, which has three Higgs doublets fields that belong to the three-dimensional reducible representation of the permutation group S3, has naturally new phenomena: there are several Higgs bosons, charged, neutral and pseuodscalar ones, and more than one potential minimum. We analyzed the stability of the minimal S3 invariant extension of the Higgs potential and show that at tree-level, the potential minimum preserving electric charge and CP symmetries, when it exists, is the global one.

title: Finite unified theories and the top quark mass
abstract: We present results of a study of two phenomenologically interesting SU (5) supersymmetric Grand Unified models, which are finite to all-loops before spontaneous symmetry breaking. The finiteness conditions provide us with relationships among the Yukawa and gauge couplings at the unification point, which in turn predict a heavy top quark mass (∼ 175 – 190 GeV).

title: Top quark mass predictions from gauge Yukawa unification
abstract: Gauge-Yukawa Unification (GYU) is a renormalization group invariant functional relation among gauge and Yukawa couplings which holds beyond the unification point in Grand Unified Theories (GUTs). Here, GYU is obtained by requiring finiteness and reduction of couplings to all orders in perturbation theory. We examine the consequences of GYU in various supersymmetric GUTs and in particular the predictions for the top quark mass. These predictions are such that they distinguish already GYU from ordinary GUTs. Moreover, when more accurate measurements of the top quark mass are available, it is expected that it will be possible to discriminate among the various GYUs.

title: CDF Run II Silicon Vertex Detector Annealing Study
abstract: Between Run II commisioning in early 2001 and the end of operations in September 2011, the Tevatron collider delivered 12 fb −1 of p ¯ p collisions at √ s = 1.96 TeV to the Collider Detector at Fermilab (CDF). During that time, the CDF silicon vertex detector was subject to radiation doses of up to 12 Mrad. After the end of operations, the silicon detector was annealed for 24 days at 18 ◦ C. In this paper, we present a measurement of the change in the bias currents for a subset of sensors during the annealing period. We also introduce a novel method for monitoring the depletion voltage throughout the annealing period. The observed bias current evolution can be characterized by a falling exponential ter m with time constant τI = 17.88 ± 0.36 ± 0.25 days, in good agreement with Hamburg-model predictions. For the depletion voltage, we observe an average decrease of (27 ± 3)% in the depletion voltage, whose evolution can similarly be described by an exponential time constant of τV = 6.21 ± 0.21 days. The depletion voltage results both deviate from the Hamburg-model predictions by roughly one standard deviation.

title: Production of $\Lambda$, $\bar{\Lambda}^0$ $\Xi^{\pm}$ and $\Omega^{\pm}$ Hyperons in $p \bar{p}$ Collisions at $\sqrt{s} = 1.96$ TeV

title: Exclusion of an exotic top quark with -4/3 electric charge using soft lepton tagging.
abstract: We present a measurement of the electric charge of the top quark using pp collisions corresponding to an integrated luminosity of 2.7 fb(-1) at the CDF II detector. We reconstruct tt events in the lepton + jets final state. We use soft lepton taggers to determine the flavor of the b jets, which we use to reconstruct the top quark's electric charge and exclude an exotic top quark with -4/3 charge at 95% confidence level. This is the strongest exclusion of the exotic charge scenario and the first to use soft leptons for this purpose.