16984011
Gauge-Yukawa Unification and the Top-Bottom Hierarchy
The consequences of Gauge-Yukawa Unification (GYU) in supersymmetric unified models on low energy physics are analyzed. We find that the observed top-bottom mass hierarchy can be explained by supersymmetric GYU and different models can be experimentally distinguished if the top quark mass does not exceed the value $\sim 185$ GeV.
125202226
Finite unification at all-loops
120143394
Finite GUTs within conventional N=1 gauge theories
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.
12010699
Top quark mass predictions from gauge Yukawa unification
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.
121936366
Finite unified theories and the top quark mass
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).
121745688
Conditions for vacuum stability in an S3 extension of the Standard Model
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.
209835699
Search for anomalous production of events with two photons and additional energetic objects at CDF
We present results of a search for anomalous production of two photons together with an electron, muon, τ lepton, missing transverse energy, or jets using pp collision data from 1.1–2.0  fb-1 of integrated luminosity collected by the Collider Detector at Fermilab (CDF). The event yields and kinematic distributions are examined for signs of new physics without favoring a specific model of new physics. The results are consistent with the standard model expectations. The search employs several new analysis techniques that significantly reduce instrumental backgrounds in channels with an electron and missing transverse energy.
16273143
Search for technicolor particles produced in association with a W Boson at CDF.
We present a search for the technicolor particles rho{T} and pi_{T} in the process pp-->rho{T}-->Wpi{T} at a center of mass energy of sqrt[s]=1.96 TeV. The search uses a data sample corresponding to approximately 1.9 fb{-1} of integrated luminosity accumulated by the CDF II detector at the Fermilab Tevatron. The event signature we consider is W-->lnu and pi{T}-->bb, bc or bu depending on the pi{T} charge. We select events with a single high-p{T} electron or muon, large missing transverse energy, and two jets. Jets corresponding to bottom quarks are identified with multiple b-tagging algorithms. The observed number of events and the invariant mass distributions are consistent with the standard model background expectations, and we exclude a region at 95% confidence level in the rho{T}-pi{T} mass plane. As a result, a large fraction of the region m(rho{T})=180-250 GeV/c{2} and m(pi{T})=95-145 GeV/c{2} is excluded.
56217752
CDF Run II Silicon Vertex Detector Annealing Study
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.