[en] A variation of the original 2006 radiative seesaw model of neutrino mass through dark matter is shown to realize the notion of inverse seesaw naturally. The dark-matter candidate here is the lightest of three real singlet scalars which may also carry flavor

[en] If neutrinos are truly Dirac fermions, the smallness of their masses may still be natural if certain symmetries exist beyond those of the standard model of quarks and leptons. We perform a systematic study of how this may occur at tree level and in one loop. We also propose a scotogenic version of the left–right gauge model with naturally small Dirac neutrino masses in one loop.

[en] An electrodeless ferrite-free fluorescent lamp of a closed-loop type ('tokamak') was studied at a driving frequency, f = 160-1000 kHz, and power of 100-250 W. The inductive discharge was ignited in the mercury-argon mixture with the help of an induction coil of several (7-15) turns made from multiple-strand (Litz) wire. The discharge parameters - current, resistance, and electric field - were calculated using the transformer model of an RF inductive discharge. They were found to be close to those measured in a plasma of a 'tokamak'-type lamp operated at the same frequency and RF power but with the use of the ferrite cores. The ferrite-free lamp had high luminous efficacy as high as 85 LPW at a frequency, f>200 kHz, and power of 100-200 W. Such a high efficacy is attributed to low coil power losses (<15 W) and hence to high lamp power efficiency, η>90%

[en] An alternative left-right model of quarks and leptons, where the SU(2)_R lepton doublet (ν, l)_R is replaced with (n, l)_R so that n_R is not the Dirac mass partner of ν_L, has been known since 1987. Previous versions assumed a global U(1)_S symmetry to allow n to be identified as a dark-matter fermion. We propose here a gauge extension by the addition of extra fermions to render the model free of gauge anomalies, and just one singlet scalar to break U(1)_S. This results in two layers of dark matter, one hidden behind the other. (orig.)

[en] Two theoretically well-motivated gauge extensions of the standard model are $SU{(3)}_C\times SU{(3)}_L\times SU{(3)}_R$ and $SU{(3)}_q\times SU{(3)}_L\times SU{(3)}_l\times SU{(3)}_R$, where $SU{(3)}_q$ is the same as $SU{(3)}_C$ and $SU{(3)}_l$ is its color leptonic counterpart. Each has three variations, according to how $SU{(3)}_R$ is broken. It is shown here for the first time that a built-in dark $U{(1)}_D$ gauge symmetry exists in all six versions. However, the corresponding symmetry breaking pattern does not reduce properly to that of the standard model, unless an additional $Z_2^{\prime }$ symmetry is defined, so that $U{(1)}_D\times Z_2^{\prime }$ is broken to $Z_2$ dark parity. The available dark matter candidates in each case include fermions, scalars, as well as vector gauge bosons. This work points to the possible unity of matter with dark matter, the origin of which may not be ad hoc.

[en] The alternative ${[SU(3)]}^4$ model of leptonic color and dark matter is discussed. It unifies at $M_U\sim {10}^{14}$ GeV and has the low-energy subgroup $SU{(3)}_q\times SU{(2)}_l\times SU{(2)}_L\times SU{(2)}_R\times U{(1)}_X$ with ${(u,h)}_R$ instead of ${(u,d)}_R$ as doublets under $SU{(2)}_R$. It has the built-in global $U(1)$ dark symmetry which is generalized $B\text{–}L$. In analogy to $SU{(3)}_q$ quark triplets, it has $SU{(2)}_l$ hemion doublets which have half-integral charges and are confined by $SU{(2)}_l$ gauge bosons (stickons). In analogy to quarkonia, their vector bound states (hemionia) are uniquely suited for exploration at a future $e^{-}{e}^{+}$ collider.

[en] A special form of the 3 × 3 Majorana neutrino mass matrix derivable from μ – τ interchange symmetry accompanied by a generalized CP transformation was obtained many years ago. It predicts θ 23 = π / 4 as well as δ CP = ± π / 2 , with θ 13 ≠ 0 . Whereas this is consistent with present data, we explore a deviation of this result which occurs naturally in a recent proposed model of radiative inverse seesaw neutrino mass.

[en] Leptoquarks have been proposed as a possible explanation of anomalies in $\overline{B}\mapsto D^{⁎}\tau \overline{\nu }$ decays, the apparent anomalies in ${(g-2)}_{\mu }$ experiments and a violation of lepton universality. Motivated by this, we examine other motivations of leptoquarks: radiatively induced neutrino masses in the presence of a discrete symmetry that prevents a tree level see-saw mechanism, gauge coupling unification, and vacuum stability at least up to the unification scale. We present a new model for radiatively generating a neutrino mass which can significantly improve gauge coupling unification at one loop. We discuss this, and other models in the light of recent work on flavour anomalies.