Abstract The féeton is the gauge boson of theory. If coupling constant extremely small, becomes a candidate for dark matter. We show that its decay to pair an electron and positron explains observed Galactic 511-keV gamma-ray excess in consistent manner. This matter decays mainly into pairs neutrino anti-neutrino. Future low-energy experiments with improved directional capability will enable capturing these signals. seesaw-motivated parameter space predicts relatively short lifetime...

The seesaw mechanism with three right-handed neutrinos has one as a well-motivated dark matter candidate if stable and the other two can explain baryon asymmetry via thermal leptogenesis scenario. We explore possibility of introducing additional particles to make neutrino in equilibrium freeze out through forbidden annihilation channel. Nowadays Universe, this channel be reactivated by strong gravitational potential such supermassive black hole our galaxy center. Fermi-LAT gamma ray data...

Dark matter with mass in the crossover range between wave dark and particle matter, around $(10^{-3},\, 10^3)\,$eV, remains relatively unexplored by terrestrial experiments. In this regime, scatters coherently macroscopic objects. The effect of coherent scattering greatly enhances accelerations targets that collisions cause a factor $\sim 10^{23}$. We propose novel torsion balance experiment test bodies different geometric sizes to detect such matter-induced acceleration. This method...

A bstract In this paper, we revisit the féeton (gauge boson of U(1) B − L symmetry) dark matter scenario, and first point out gauge symmetry can be a linear combination – SM hypercharge symmetries. With redefinition charge fermions, coupling between electron enhanced. After showing parameter space required from DM stability cosmic production, discuss potential for verifying them in direct detection experiments. The results show that future experiments, such as SuperCDMS, have sensitivity to...

Atomic dark matter is usually considered to be produced asymmetrically in the early Universe. In this work, we first propose that symmetric atomic can thermally through freeze-out mechanism. The dominant atom antiatom annihilation channel rearrangement. It has a geometrical cross section much larger than of elementary fermions. After formation, process further depletes particles and finally freezes out. To give observed relic, atoms are naturally ultraheavy, ranging from <a:math...

It is known that two heavy Majorana right-handed neutrinos are sufficient to generate the baryon asymmetry in present universe. Thus, it interesting identify third neutrino N with dark matter. We impose a new discrete symmetry Z2 on this matter stabilize it. However, U(1)B−L gauge boson A′ couples N. If B−L breaking scale VB−L sufficiently low, can be thermal bath. find relic explain abundance for VB−L∼O(10) TeV. After considering all constraints from existing experiments, narrow mass region...

In this paper, we revisit the f\'eeton (gauge boson of $U(1)_{B-L}$ symmetry) dark matter scenario, and first point out $U(1)$ gauge symmetry can be a linear combination $B-L$ SM hypercharge symmetries. With redefinition charge fermions, coupling between electron enhanced. After showing parameter space required from DM stability cosmic production, discuss potential for verifying them in direct detection experiments. The results show that future experiments, such as SuperCDMS, have...

The f\'eeton is the gauge boson of $U(1)_{B-L}$ theory. If coupling constant extremely small, it becomes a candidate for dark matter. We show that its decay to pair electron and positron explains observed Galactic 511-keV gamma-ray excess in consistent manner. This matter decays mainly into pairs neutrino anti-neutrino. Future low-energy experiments with improved directional capability make possible capture those signals. seesaw-motivated parameter space predicts relatively short lifetime...