1,341 research outputs found
Muon specific two-Higgs-doublet model
We investigate a new type of a two-Higgs-doublet model as a solution of the
muon anomaly. We impose a softly-broken symmetry to forbid tree
level flavor changing neutral currents in a natural way. This symmetry
restricts the structure of Yukawa couplings. As a result, extra Higgs boson
couplings to muons are enhanced by a factor of , while their
couplings to all the other standard model fermions are suppressed by
. Thanks to this coupling property, we can avoid the constraint from
leptonic decays in contrast to the lepton specific two-Higgs-doublet
model, which can explain the muon within the 2 level but cannot
within the level due to this constraint. We find that the model can
explain the muon within the 1 level satisfying constraints from
perturbative unitarity, vacuum stability, electroweak precision measurements,
and current LHC data.Comment: 24 pages, 3 figure
Changing Wealth Inequality in Japan
The 13th Next-Generation Global Workshop第13回次世代グローバルワークショップテーマ: New Risks and Resilience in Asian Societies and the World 日程: 21-23 November, 2020 開催場所: ベトナム社会科学院(ハノイ)/Vietnam Academy of Social Sciences(No. 1 Lieu Giai street, Ba Dinh, Hanoi, Vietnam) ※Due to the COVID-19, the workshop will be held at ONLINE for overseas participants(not from Vietnam)/ONSITE for Vietnamese participants
Gravitational Wave Background from Population III Stars
We estimate the gravitational wave (GW) background from Population III (Pop
III) stars using the results from our hydrodynamic simulations (Suwa et al.
2007). We calculate gravitational waveforms from matter motions and anisotropic
neutrino emissions for single Pop III stars. We find that the GW amplitudes
from matter motions are dominant until just after bounce, but those from
neutrinos dominate later on at frequencies below Hz in the GW
spectrum. Computing the overall signal produced by the ensemble of such Pop III
stars, we find that the resultant density parameter of the GW background peaks
at the amplitude of in the frequency interval
Hz. We show that such signals, depending on the formation rate of
Pop III stars, can be within the detection limits of future planned
interferometers such as DECIGO and BBO in the frequency interval of Hz. Our results suggest that the detection of the GW background from Pop
III stars can be an important tool to supply the information about the star
formation history in the early universe.Comment: 4 pages, 3 figures, accepted for publication in ApJ
Quantum Nucleation of Two-Flavor Quark Matter in Neutron Stars
Rates for nucleation of two-flavor quark matter in a neutron star core,
originally composed of nuclear matter in equilibrium, are calculated at
zero temperature by a quantum tunneling analysis incorporating the
electrostatic energy. We find that a nucleated droplet would develop into bulk
matter due to electron screening effects.Comment: 8 pages (LaTeX, PTP style), 4 Postscript figures, to be published in
Prog. Theor. Phys. (Letters
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