Related papers: FCNC portals to the dark sector
The investigation of flavour-changing neutral current transitions(FCNC) involving the top quark are only possible with new theoretical frameworks that extend the Standard Model(SM), given that these transitions are almost entirely…
Recent experimental results on exclusive semi-tauonic B meson decays, B -> D(*) tau nu, showing sizable deviations from the standard model prediction, suggest a new physics in which the structure of the relevant weak charged interaction may…
A dark sector resembling the standard model, where the abundance of matter is explained by baryon and lepton asymmetries, and stable constituents bind to form atoms, is a theoretically appealing possibility. We show that a minimal model…
We consider scenarios where Dark Matter (DM) particles carry baryon and/or lepton numbers, which can be defined if there exist operators connecting the dark to the visible sector. As a result, the DM fields become intimately linked to the…
We investigate the prospects for detecting a hidden sector at an $e^+ e^-$ collider. The hidden sector is assumed to be composed of invisible particles that carry no charges under the Standard Model gauge interactions, and whose primary…
We studied a simple model of hidden sector consists of a Dirac fermion $\chi$ and a spontaneously broken $U(1)_s$ symmetry. The dark sector is connected to the Standard Model(SM) via three righthanded SM singlet neutrinos, $N_R$'s, and the…
A minimal fermion-scalar preonic model containing two fermionic and one scalar preons is proposed. This scheme allows to prevent the occurrence of undesired SM-level particles, namely leptons and quarks with unusual electric charges.…
An overview of searches for top quark flavour changing neutral currents (FCNC) from the CDF, D0, ATLAS and CMS collaborations is presented. The FCNC interactions of top quarks are probed through the anomalous decays and production channels.…
In the SM gauge symmetries and fermion content of neutrinos, charged leptons and quarks, we study the effective four-fermion operators of Einstein-Cartan type and their contributions to the Schwinger-Dyson equations of fermion self-energy…
In the framework of potential models for heavy quarkonium the mass spectrum for the system ($\bar b c$) is considered. Spin-dependent splittings, taking into account a change of a constant for effective coulomb interaction between the…
We consider theories where dark matter is composed of a thermal relic of weak scale mass, whose couplings to the Standard Model (SM) are however too small to give rise to the observed abundance. Instead, the abundance is set by annihilation…
The evidence for the observation of the Higgs spin-0-boson as a manifestation of a scalar field provides the missing corner stone for the standard model of particles (SM). However, the SM fails to explain the non-visible but gravitationally…
Baryon number violation in the visible sector induced by anti-baryonic dark matter provides a viable mechanism for low-scale baryogenesis. Two of the most sensitive probes of this scenario are neutron decay processes such as $n \to…
We examine extensions of the MSSM with more than one generation of Higgs bosons. If one assumes that a symmetry eliminates the tree-level FCNC, then the extra scalar bosons do not acquire VEVs, do not couple to fermions and do not mix with…
We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle physics community. More specifically, we report on the determination of the light-quark masses, the form…
We consider a dark sector with $SU(3)_C \times U(1)_Y \times U(1)_X$ and three families of dark fermions that are chiral under dark $U(1)_X$ gauge symmetry, whereas scalar dark matter $X$ is the SM singlet. $U(1)_X$ dark symmetry is…
We present a comprehensive, model-independent analysis of rare flavour-changing neutral current (FCNC) interactions of the top quark within an effective field theory framework. Beginning with a general parametrisation of top-FCNC couplings,…
In the context of SUSY grand unification a link is established between the hadronic and leptonic soft breaking sectors. Such relation is here exploited in particular for FCNC processes in B physics. It is shown how bounds on leptonic FCNC…
We investigate the sensitivity of future searches for the top-Higgs boson Flavour Changing Neutral Current (FCNC) couplings $tqh$~($q= u, c$) at the proposed High Energy Large Hadron Collider~(HE-LHC) and Future Circular Collider in…
The Standard Model Effective Field Theory (SMEFT) and the Low Energy Effective Field Theory (LEFT) can be extended by adding additional spin 0, 1/2 and 1 dark matter particles which are singlets under the Standard Model (SM) gauge group. We…