Related papers: A Flavor Specific Chiral $U(1)_X$ Framework for Ex…
We derive constraints on the couplings of light vector particles to all first-generation Standard Model fermions using leptonic decays of the charged pion, $\pi^+\to e^+ \nu_e X_\mu$. In models where the net charge to which $X_\mu$ couples…
Excited beryllium has been observed to decay into electron-positron pairs with a $6.8~\sigma$ anomaly. The process is properly explained by a 17 MeV proto-phobic vector boson. In present work, we consider a family-nonuniversal…
2-Higgs Doublet Models (2HDMs) typically need to invoke an ad-hoc discrete symmetry to avoid severe flavor bounds and in addition feature massless neutrinos, thus falling short of naturally complying with existing data. However, when…
We examine theoretical features of $U(1)_X$ extensions of the Standard Model whose quantum anomalies are canceled per generation. Similarly to other versions, the theory consists of a Two-Higgs-Doublet Model plus a scalar singlet embedded…
The 6.8$\sigma$ anomaly in excited 8Be nuclear decays via internal pair creation is fit well by a new particle interpretation. In a previous analysis, we showed that a 17 MeV protophobic gauge boson provides a particle physics explanation…
We report on an interesting realization of the QCD axion, with mass in the range $\mathcal{O}(10)$ MeV. It has previously been shown that although this scenario is stringently constrained from multiple sources, the model remains viable for…
A non anomalous horizontal $U(1)_H$ gauge symmetry can be responsible for the fermion mass hierarchies of the minimal supersymmetric standard model. Imposing the consistency conditions for the absence of gauge anomalies yields the following…
The new measurement of $W$-boson mass by the CDF collaboration revealed a remarkable $7\sigma$ disagreement with the Standard Model (SM) prediction. If confirmed by other experiments, then the disagreement strongly indicates the existence…
The new measurement of $W$-boson mass by the CDF collaboration revealed a remarkable $7\sigma$ disagreement with the Standard Model (SM) prediction. If confirmed by other experiments, then the disagreement strongly indicates the existence…
We address the presently reported significant flavor anomalies in the $K$ and $B$ meson systems such as the CP violating Kaon decay ($\epsilon'/\epsilon$) and lepton-flavor universality violation in $B$ meson decays ($R_{K^{(*)}},$ and also…
We consider a simple extension of the Standard Model with flavor-dependent $U(1)'$, that has been proposed to explain some of $B$-meson anomalies recently reported at LHCb. The $U(1)'$ charge is chosen as a linear combination of…
We attempt to simultaneously explain the neutrino oscillation data and the observed $(g-2)_{e,\mu}$ in a hidden gauge $U(1)_X$ model where all the Standard Model(SM) fields are $U(1)_X$ singlets. The minimal version of this model calls for…
We have witnessed some flavor anomalies appeared in the past years, and explanations based on extended gauge sectors are among the most popular solutions. These beyond the Standard Model (SM) theories often assume flavor changing…
The flavor problem, neutrino physics and the fermion mass hierarchy are important motivations to extend the Standard Model into the TeV scale. A new family non-universal extension is presented with three Higgs doublets, one Higgs singlet…
We investigate the landscape of constraints on MeV-GeV scale, hidden U(1) forces with nonzero axial-vector couplings to Standard Model fermions. While the purely vector-coupled dark photon, which may arise from kinetic mixing, is a…
We propose an extra-dimension framework on the orbifold $S^1/Z_2$ for understanding the origin of the fermion mass and mixing hierarchies. Introducing the flavor symmetry $G_F(=${\it non-Abelian}$\times${\it Abelian}) as well as the extra…
The framed standard model (FSM) predicts a $0^+$ boson with mass around 20 MeV in the "hidden sector", which mixes at tree level with the standard Higgs $h_W$ and hence acquires small couplings to quarks and leptons which can be calculated…
We consider the Standard Model (SM) with the addition of a $\mathrm{U(1)^\prime}$ gauge symmetry and a complete fourth family of quarks and leptons which are vector-like with respect to the full $\mathrm{SU(3)_C}\times \mathrm{SU(2)_L}…
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…
We study the reasonable requirements of two anomalous $U(1)$s in a flavored-axion framework for the anomaly cancellations of both $U(1)$-mixed gravity and $U(1)_Y\times[U(1)]^2$ which in turn determine the $U(1)_Y$ charges where $U(1)_Y$ is…