Related papers: FCNC portals to the dark sector
The minimal standard model of quarks and leptons is extended with a set of vectorlike fermions to allow baryon number $B$ to become a gauged $U(1)_B$ symmetry. The $B$ assignments of the new particles are determined by renormalizable…
In the multi-component configurations of dark matter phenomenology, we propose a minimal two-component configuration which is an extension of the Standard Model with only three new fields; one scalar and one fermion interact with the…
Decays of the top quark induced by flavor changing neutral currents (FCNC) are known to be extremely rare events within the Standard Model. This is so not only for the decay modes into gauge bosons, but most notably in the case of the Higgs…
In the littlest Higgs model with T-parity (LHT) new flavor-changing interactions between mirror fermions and the Standard Model (SM) fermions can induce various FCNC decays for B-mesons, Z-boson and Higgs boson. Since all these decays…
In Standard Model Effective Field Theory (SMEFT), invisible neutron decay arises from d = 12 operators. Adding new light particles to the field content of the SM, such as right-handed neutrinos, allows one to construct operators for…
Extensions of the Standard Model (SM) gauge group with a new $U(1)_X$ predict an additional gauge boson. Through kinetic mixing with the SM photons featured by a coupling $\epsilon$, the ensuing so-called dark photons $\gamma'$, which…
We consider an experiment to search for dark sector particles in dark photon kinetic mixing model by analyze invisible and semi-invisible decays of neutral mesons $M^0 = \pi^0$, $\eta$, $\eta'$, $\omega$, $f_2(1270)$, produced in the NA64…
These two lectures constitute a reappraisal and an update of the status of the Flavour Changing Neutral Current (FCNC) and CP violation issues in supersymmetry. The first lecture discusses these points in the framework of the Minimal…
The study investigates flavor-changing neutral current (FCNC) decays of $B$ and $K$ mesons in the context of a dark $U(1)_D$ model with a dark photon/dark $Z$ mass between 10 MeV and 2 GeV. While the model improves the fit to certain decay…
We present a new model of "Stealth Dark Matter": a composite baryonic scalar of an $SU(N_D)$ strongly-coupled theory with even $N_D \geq 4$. All mass scales are technically natural, and dark matter stability is automatic without imposing an…
We develop a systematic effective field theory framework for studying $|\Delta B|=2$ interactions across energy scales. Using chiral symmetry, we construct the complete and non-redundant set of operators governing these interactions at low…
The flavor-changing neutral current decay processes of the $B$ and $B_c$ mesons with the final states involving spin-$1/2$ particles are investigated. By considering the background of the Standard Model where $\nu\bar\nu$ contributes the…
By using the effective potential approximation and taking into account the dominant top quark and scalar top quark loops, radiative corrections to MSSM Higgs potential are computed in the presence of the supersymmetric CP-violating phases.…
For any new physics possibly emerging in the future B experiments, the problem is how to extract the signals from the SM background. We consider the decay $b\to s s\bar d$ which is very small in the SM. In the MSSM this decay is possibly…
We present a detailed study of Delta F=2 observables and of rare K^+(K_L) and B_{s,d} meson decays in a "Minimal Theory of Fermion Masses" (MTFM). In this theory Yukawa couplings are generated through the mixing with heavy vectorlike (VF)…
The Fermilab Short-Baseline Neutrino (SBN) experiments, MicroBooNE, ICARUS, and SBND, are expected to have significant sensitivity to light weakly coupled hidden sector particles. Here we study the capability of the SBN experiments to probe…
The unique Higgs physics opportunities accessible at the CERN Future Circular Collider (FCC) in electron-positron ($\sqrt{s}$ = 125, 240, 350 GeV) and proton-proton ($\sqrt{s}$ = 100 TeV) collisions, are succinctly summarized. Thanks to the…
This work explores exotic signatures from confining dark sectors that may arise in the $e^+e^-$ collision mode at the Future Circular Collider. Assuming the Higgs boson mediates the interaction between the Standard Model and the dark…
The Minimal Supersymmetric Standard Model (MSSM) with explicit CP violation is studied with the help of the di-photon decay channel of the lightest neutral Higgs boson. Effects of CP violation, entering via the scalar/pseudo-scalar mixing…
In the context of a warped extra-dimension with Standard Model fields in the bulk, we obtain the general flavor structure of the Higgs couplings to fermions. These couplings will be generically misaligned with respect to the fermion mass…