3,665 research outputs found
Supersymmetric Higgs-portal and X-ray lines
We consider a Dirac singlet fermion as thermal dark matter for explaining the
X-ray line in the context of a supersymmetric Higgs-portal model or a
generalized Dirac NMSSM. The Dirac singlet fermion gets a mass splitting due to
their Yukawa couplings to two Higgs doublets and their superpartners,
Higgsinos, after electroweak symmetry breaking. We show that a correct relic
density can be obtained from thermal freeze-out, due to the co-annihilation
with Higgsinos for the same Yukawa couplings. We discuss the phenomenology of
the Higgsinos in this model such as displaced vertices at the LHC.Comment: 15 pages, 4 figures, references adde
Cluster X-ray line at from axion-like dark matter
The recently reported X-ray line signal at
from a stacked spectrum of various galaxy clusters and the Andromeda galaxy may
be originating from a decaying dark matter particle of the mass . A
light axion-like scalar is suggested as a natural candidate for dark matter and
its production mechanisms are closely examined. We show that the right amount
of axion relic density with the preferred parameters, and , can be naturally obtainable
from the decay of inflaton. If the axions were produced from the saxion decay,
it could not have constituted the total relic density due to the bound from
structure formation. Nonetheless, the saxion decay is an interesting
possibility, because the line and dark radiation can be
addressed simultaneously, being consistent with the Planck data. Small
misalignment angles of the axion, ranging between depending on the reheating temperature, can also be the source of
axion production. The model with axion misalignment can satisfy the constraints
for structure formation and iso-curvature perturbation.Comment: 14 pages, significant changes in the form, matched to the journal
versio
-meson anomalies and Higgs physics in flavored model
We consider a simple extension of the Standard Model with flavor-dependent
, that has been proposed to explain some of -meson anomalies recently
reported at LHCb. The charge is chosen as a linear combination of
anomaly-free and . In this model, the flavor structure
in the SM is restricted due to flavor-dependent charges, in particular,
quark mixings are induced by a small vacuum expectation value of the extra
Higgs doublet. As a result, it is natural to get sizable flavor-violating
Yukawa couplings of heavy Higgs bosons involving the bottom quark. In this
article, we focus on the phenomenology of the Higgs sector of the model
including extra Higgs doublet and singlet scalars. We impose various bounds on
the extended Higgs sector from Higgs and electroweak precision data, -meson
mixings and decays as well as unitarity and stability bounds, then discuss the
productions and decays of heavy Higgs bosons at the LHC.Comment: 40 pages, 11 figures, 1 table; v2: references added; v3: accepted
version for publication in EPJ
Diboson Excesses Demystified in Effective Field Theory Approach
We study the collider implication of a neutral resonance which decays to
several diboson final states such as , , and via a
minimal set of effective operators. We consider both CP-even and CP-odd bosonic
states with spin 0, 1, or 2. The production cross sections for the bosonic
resonance states are obtained with the effective operators involving gluons
(and quarks), and the branching fractions are obtained with the operators
responsible for the interactions with electroweak gauge bosons. We demonstrate
that each scenario allows for a broad parameter space which could accommodate
the recently-reported intriguing excesses in the ATLAS diboson final states,
and discuss how the CP states and spin information of the resonance can be
extracted at the LHC run II.Comment: 22 pages, 6 figures, main text slightly modified with results
unchange
Orai1 inhibitor STIM2?? regulates myogenesis by controlling SOCE dependent transcriptional factors
Store-operated Ca2+ entry (SOCE), the fundamental Ca2+ signaling mechanism in myogenesis, is mediated by stromal interaction molecule (STIM), which senses the depletion of endoplasmic reticulum Ca2+ stores and induces Ca2+ influx by activating Orai channels in the plasma membrane. Recently, STIM2??, an eight-residue-inserted splice variant of STIM2, was found to act as an inhibitor of SOCE. Although a previous study demonstrated an increase in STIM2?? splicing during in vitro differentiation of skeletal muscle, the underlying mechanism and detailed function of STIM2?? in myogenesis remain unclear. In this study, we investigated the function of STIM2?? in myogenesis using the C2C12 cell line with RNA interference-mediated knockdown and CRISPR-Cas-mediated knockout approaches. Deletion of STIM2?? delayed myogenic differentiation through the MEF2C and NFAT4 pathway in C2C12 cells. Further, loss of STIM2?? increased cell proliferation by altering Ca2+ homeostasis and inhibited cell cycle arrest mediated by the cyclin D1-CDK4 degradation pathway. Thus, this study identified a previously unknown function of STIM2?? in myogenesis and improves the understanding of how cells effectively regulate the development process via alternative splicing
Flavor and CP-violating Higgs sector in two Higgs doublet models with
We investigate the role of a local symmetry for the problem of CP
violation in the effective theory for two Higgs doublet models and its
microscopic counterparts. First, in two Higgs doublet models with , we
show that the higher-dimensional operators in the scalar potential violate the
CP symmetry with an interplay with the mixing mass parameter, giving rise to
small mixings between CP-even and CP-odd scalars. Motivated by the -meson
anomalies in recent years, we take the flavored to be a benchmark model
for specifying the flavor structure. Then, we calculate the electric dipole
moment of electron (eEDM) at two loops due to the CP-violating
higher-dimensional operators and identify the correlation between the masses of
heavy Higgs bosons and the cutoff scale from the bound on eEDM. We also comment
on the possibility of making an independent test of the CP violation in the
collider searches for heavy Higgs bosons. Finally, we show how the obtained
eEDM results in the effective theory can be used to constrain microscopic
models with an explicit CP violation in the partially decoupled or dark
sectors.Comment: 37 pages, 5 figures, Journal versio
Malignancies in Korean Patients with Inflammatory Myopathy
The aim of this study was to assess the prevalence and the common type of malignancies in Korean patients with polymyositis (PM) and dermatomyositis (DM) and to evaluate the differences of clinical and laboratory findings between patients with malignancy and those without malignancy. Forty-one Korean patients, who were diagnosed as PM or DM, were enrolled in this study. They fulfilled the Bohan and Peter's criteria for a definite diagnosis of PM and DM. Patients with PM were 25 and those with DM were 16. Eleven out of 41 patients (26.8%) had malignancies. The malignancy was diagnosed simultaneously or later in 81.8% of patients with inflammatory myopathy (IM). The breast cancer was the most common malignancy. In this study, forty three years old as a screening age for malignancy had 88.9% sensitivity and 50.2% specificity. The serum levels of creatine kinase (CK) were significantly lower in patients with malignancy than those without malignancy
- …