750 research outputs found
violating mode of the stoponium decay into
We show that a novel decay mode of the bound state of stop-anti-stop
pair in the ground state may have a
significant branching ratio if the violating mixing appears in the stop
sector, even after we apply the stringent constraint from the measurement of
the electric dipole moment (EDM) of the electron. We show that the branching
ratio can be as large as 10% in some parameter space that it may be detectable
at the LHC.Comment: 16 pages, 4 figure
Higgcision in the Two-Higgs Doublet Models
We perform global fits to general two-Higgs doublet models (2HDMs) with
generalized couplings using the most updated data from ATLAS, CMS, and
Tevatron. We include both scenarios with CP-conserving and CP-violating
couplings. By relaxing the requirement on the discrete symmetries that are
often imposed on the Yukawa couplings, we try to see which of the 2HDMs is
preferred. We found that (i) Higgcision in 2HDMs can be performed efficiently
by using only 4 parameters including the charged Higgs contributions to the
Higgs couplings to two photons, (ii) the differences among various types of
2HDMs are very small with respect to the chi-square fits, (iii) is
constrained to be small, (iv) the -values for various fits in 2HDMs are
worse than that of the standard model. Finally, we put emphasis on our findings
that future precision measurements of the Higgs coupling to the scalar
top-quark bilinear () and may endow us with the
discriminating power among various types of 2HDMs especially when
deviates from its SM value 1.Comment: 46 pages, 4 tables, 22 figures, references added, to appear in JHE
Boosted dark matter from primordial black holes produced in a first-order phase transition
During a cosmological first-order phase transition in a dark sector, fermion
dark matter particles can form macroscopic Fermi balls that collapse to
primordial black holes (PBHs) under certain conditions. The evaporation of the
PBHs produces a boosted flux, which may be detectable if couples
to visible matter. We consider the interaction of with electrons, and
calculate signals of the dark matter flux in the XENON1T, XENONnT,
Super-Kamiokande and Hyper-Kamiokande experiments. A correlated gravitational
wave signal from the phase transition can be observed at THEIA and Ares.
An amount of dark radiation measurable by CMB-S4 is an epiphenomenon of the
phase transition.Comment: 14 pages, 2 figures, 1 table. Version to appear in JHE
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