相关论文: Hypercharge-Universal Topcolor
While it is known that third family hypercharge models can explain the neutral current $B-$anomalies, it was hitherto unclear whether the $Z-Z^\prime$ mixing predicted by such models could simultaneously fit electroweak precision…
We present constraints on Wilson coefficients from a combined fit to data from top-quark and beauty-physics measurements within the Standard Model effective field theory. We consider present data on top-quark pair production and decay,…
I discuss vacuum alignment and CP violation in technicolor theories of electroweak and flavor symmetry breaking. I review the surprising appearance of rational phase solutions in the technifermion sector and propose a new solution of the…
Technicolor and other theories of dynamical electroweak symmetry breaking invoke chiral symmetry breaking triggered by strong gauge-dynamics, analogous to that found in QCD, to explain the observed W, Z, and fermion masses. In this talk we…
In a previous analysis presented in hep-ph/0412166, electroweak constraints were given on arbitrary linear combinations of a set of dimension-6 operators. Flavor universality and thus U(3)^5 flavor symmetry were assumed for the operators.…
The lack of evidence for superparticles at the CERN LHC, along with the rather high value of the Higgs mass, has sharpened the perception that supersymmetric model parameter space is highly electroweak fine-tuned (EWFT). We compare three…
We present an extensive analysis of gauge-mediated supersymmetry breaking models with minimal and non-minimal flavour violation. We first demonstrate that low-energy, precision electroweak, and cosmological constraints exclude large…
Extensions of the standard model with universal extra dimensions are interesting both as phenomenological templates as well as model-building fertile ground. For instance, they are one the prototypes for theories exhibiting compressed…
Recent LEP results on electroweak precision measurements are reviewed. Line-shape and asymmetries analysis on the Z peak is described. Then, the consistency of the Standard Model predictions with experimental data and consequent limits on…
We consider a two-dimensional generalization of the Su-Schrieffer-Heeger model which is known to possess a non-trivial topological band structure. For this model, which is characterized by a single parameter, the hopping ratio $0 \leq r\leq…
If in addition to the standard model fields, a new pseudoscalar field that couples to hypercharge topological number density, the hypercharge axion, exists, it can be produced in colliders in association with photons or Z bosons, and…
I propose a resolution of the strong CP problem of quarks based on vacuum alignment in theories of dynamically broken electroweak and flavor symmetries. Mixing in the neutral B and K--meson systems is used to restrict the form of quark mass…
We theoretically study the upper critical magnetic fields at zero temperature in a quasi-two-dimensional (Q2D) superconductor in the parallel and perpendicular fields, $H_{c2}^{\parallel}(0)$ and $H_{c2}^{\perp}$(0), respectively. We find…
Slowly walking technicolor models provide a mechanism for electroweak symmetry breaking whose nonperturbative lattice investigation is rather challenging. Here we demonstrate walking near a conformal fixed point considering the 2-d lattice…
Conventional technicolor models with light charged technipions ($\pi ^{\pm} _T$) lead to an unacceptably large contribution to $t\ra {\pi ^+_T} b$ decay rate. Topcolor-assisted technicolor models also have additional PGBs called top-pions…
In the framework of general 3-3-1 models, we perform a global $\chi ^2$ fit at $95\%$ C.L. to the updated Z pole observables, including new data from atomic parity violation. We found scenarios where specific realizations of 3-3-1 models…
Vacuum alignment in technicolor models provides an attractive origin for the quarks' CP violation and, possibly, a natural solution for the strong-CP problem of QCD. We discuss these topics in this paper. Then we apply them to determine…
The evolution of Standard Model gauge couplings is studied in a non-supersymmetric scenario in which the hierarchy problem is resolved by Higgs compositeness above the weak scale. It is argued that massiveness of the top quark combined with…
Hierarchical masses of quarks and leptons are addressed by imposing horizontal symmetries. In supersymmetric Standard Models, the same symmetries play a role in suppressing flavor violating processes induced by supersymmetric particles.…
Using the framework of deconstruction, we construct simple, weakly-coupled supersymmetric models that explain the Standard Model flavor hierarchy and produce a flavorful soft spectrum compatible with precision limits. Electroweak symmetry…