Related papers: New flavor changing interactions in extended gauge…
Despite the tremendous success of the Standard Model, the arguments for the necessity of an extension are compelling. An attractive option is provided by Two-Higgs-Doublet models, due to their simplicity and them being the low-energy limit…
We study a simple ultraviolet(UV) complete and anomaly free $Z'$ model based on a U$(1)'$ gauge family symmetry without introducing extra fermions beyond the standard model. The U$(1)'$ group is diagonal in the three family space in which…
All couplings of a new heavy gauge boson to ordinary fermions can be determined in a model-independent way at a large $e^+e^-$ collider for large enough statistics. No such determination is possible at LEP 200, however, because its design…
Standard Model may allow an extended gauge sector with anomaly-free flavored gauge symmetries, such as $L_{i} - L_{j}$, $B_{i} - L_{j}$, and $B - 3L_{i}$, where $i,j=1,2,3$ are flavor indices. We investigate phenomenological implications of…
We investigate the flavour changing neutral currents (FCNC) generated by dimension six four-fermion operators at the Large Hadron-Electron Collider (LHeC) proposed at CERN in an effective approach. This is performed by monte carlo analysis…
The reactions e+e- -> t bar-c nu_e bar-nu_e, t bar-c e+ e- are very sensitive probes of the flavor-changing-scalar couplings which can occur in a model with one extra Higgs doublet. At the Next Linear Collider, with a center of mass energy…
It is possible that the standard model (SM) is replaced around some transition energy $\E_{tr}$ by a new, possibly Higgsless, ``flavor gauge theory'' such that the Yukawa (running) parameters of SM at $E \sim \E_{tr}$ show up an…
We study a vectorial gauge theory with gauge group SU(Nc) and a variable number, Nf, of massless fermions in the fundamental representation of this group. Using approximate solutions of Schwinger-Dyson and Bethe-Salpeter equations, we…
Flavor changing neutral current processes are studied in the littlest Higgs model with T-parity. It is found that the logarithmic divergence reported earlier in Z boson flavor changing processes is exactly canceled by contributions from…
After we study the 6-dimensional ${\cal N} = (1, 1)$ supersymmetry breaking and $R$ symmetry breaking on $M^4\times T^2/Z_n$, we construct two ${\cal N} = (1, 1)$ supersymmetric $E_6$ models on $M^4\times T^2/Z_3$ where $E_6$ is broken down…
Based on a specific model with U(3) family gauge symmetry at $10^3$ TeV scale, we show its experimental signatures to search for. Since the gauge symmetry is introduced with a special purpose, its gauge coupling constant and gauge boson…
This reports summarizes the activities of the Charged Lepton Flavor Violation group of the 2022 Community Summer Study. Charged lepton flavor violating reactions provide unique information on the scale and dynamics of flavor generation, and…
We present a extension of the 3-3-1 gauge model supplemented by an $A_4$ flavor symmetry and cyclic discrete symmetries, including $Z_2$, $Z_2'$, $Z_3$, $Z_4$, $Z_7$ and $Z_{10}$. The model successfully reproduces the observed SM fermion…
We explore quark interactions mediated by new gauge bosons of masses in the 0.3 - 50 GeV range. A tight upper limit on the gauge coupling of light Z' bosons is imposed by the anomaly cancellation conditions in conjunction with collider…
We investigate collider signals for gauged flavor symmetries that have been proposed in models of dynamical electroweak symmetry breaking and fermion mass generation. We consider the limits on the masses of the gauge bosons in these models…
The origin of mass must lie in physics beyond the Standard Model. Dynamical electroweak symmetry breaking models like technicolor can generate masses for the W and Z bosons. Providing the large top quark mass and large top-bottom mass…
Prospects to search for a new massless neutral gauge boson, the paraphoton, in e+ e- collisions at center-of-mass energies of 0.5 and 1 TeV are studied. The paraphoton naturally appears in models with abelian kinetic mixing. A possible…
We consider the lepton-flavor violating(LFV) processes $l_{i}\to l_{j}\gamma$ in the framework of topcolor assisted technicolor(TC2) models. We find that the new gauge boson $Z^{\prime}$ predicted by TC2 models can give significantly…
The flavor changing neutral current tcV (V=\gamma,Z) couplings in the production vertex for the process $e^+e^-\to t\bar c$ or $\bar t c$ in the standard model are investigated. The precise calculations keeping all quark masses non-zero are…
In a truly model-independent approach, we reexamine a minimal extension of the Standard Model (SM) through the introduction of an additional $U(1)$ symmetry leading to a new neutral gauge boson ($Z'$), allowing its kinetic mixing with the…