254 research outputs found
Testing Higgs models via the vertex by a recoil method at the International Linear Collider
In general, charged Higgs bosons appear in non-minimal Higgs models.
The vertex is known to be related to the violation of the
global symmetry (custodial symmetry) in the Higgs sector. Its magnitude
strongly depends on the structure of the exotic Higgs models which contain
higher isospin representations such as triplet Higgs bosons. We study
the possibility of measuring the vertex via single charged
Higgs boson production associated with the boson at the International
Linear Collider (ILC) by using the recoil method. The feasibility of the signal
is analyzed assuming the polarized
electron and positron beams and the expected detector performance for the
resolution of the two-jet system at the ILC. The background events can be
reduced to a considerable extent by imposing the kinematic cuts even if we take
into account the initial state radiation. For a relatively light charged Higgs
boson whose mass is in the region of 120-130 GeV , the vertex would be precisely testable especially
when the decay of is lepton specific. The exoticness of the extended
Higgs sector can be explored by using combined information for this vertex and
the rho parameter.Comment: 22 pages, 23 figure
Radiative corrections to electroweak parameters in the Higgs triplet model and implication with the recent Higgs boson searches
We study radiative corrections to the electroweak parameters in the Higgs
model with the Y=1 triplet field, which is introduced in the scenario of
generating neutrino masses based on the so-called type II seesaw mechanism. In
this model, the rho parameter deviates from unity at the tree level.
Consequently, the electroweak sector of the model is described by the four
input parameters such as , , and
. We calculate the one loop contribution to the W boson mass as
well as to the rho parameter in order to clarify the possible mass spectrum of
the extra Higgs bosons under the constraint from the electroweak precision
data. We find that the hierarchical mass spectrum among ,
and (or ) is favored by the precision data especially for the case of
, where , , and
are the doubly-charged, singly-charged, CP-odd and CP-even Higgs bosons
mainly originated from the triplet field. We also discuss phenomenological
consequences of such a mass spectrum with relatively large mass splitting. The
decay rate of the Higgs boson decay into two photons is evaluated under the
constraint from the electroweak precision data, regarding the recent Higgs
boson searches at the CERN LHC.Comment: 17 pages, 23 figures, version published in PRD, title slightly
modifie
Measurements of the charge-to-mass ratio of particles trapped by the Paul Trap for education
Paul traps are devices that confine particles using an oscillating electric
field and have been used in undergraduate experimental classes at universities.
Owing to the requirement of a high voltage of several thousand volts, no cases
of use in middle and high schools are available. Therefore, we developed an
all-in-one-type Paul trap device that included a high-voltage transformer. The
Paul trap can be equipped with three different types of electrode attachments,
ring-type, and linear-type , and the trap image can be observed using a
built-in web camera. For example, the charge-to-mass ratio of particles was
measured with different types of attachments, and it was shown that reasonable
values could be obtained. This type of trap is currently used at several
educational facilities in Japan.Comment: 6 pages, 12 figure
Indium coverage of the Si(111)- 7×3 -in surface
The indium coverage of the Si(111)-√7 × √3-In surface is investigated by means of x-ray photoelectron spectroscopy and first-principles density functional theory calculations. Both experimental and theoretical results indicate that the In coverage is a double layer rather than a single layer. Moreover, the atomic structure of the Si(111)-√7 × √3-In surface is discussed by comparing experimental with simulated scanning tunneling microscopy (STM) images and scanning tunneling spectra with the calculated density of states. Our structural assignment agrees with previous studies, except for the interpretation of experimental STM images
Suppression of diet-induced atherosclerosis in low density lipoprotein receptor knockout mice overexpressing lipoprotein lipase.
Models of Yukawa interaction in the two Higgs doublet model, and their collider phenomenology
Possible models of Yukawa interaction are discussed in the two Higgs doublet
model (THDM) under the discrete symmetry imposed to avoid the flavor changing
neutral current at the leading order. It is known that there are four types of
such models corresponding to the possible different assignment of charges for
the discrete symmetry on quarks and leptons. We first examine decay properties
of Higgs bosons in each type of the models, and summarize constraints on the
models from current experimental data. We then shed light on the differences
among these models in collider phenomenology. In particular, we mainly discuss
so-called the Type-II THDM and the Type-X THDM. The Type-II THDM corresponds to
the model with the same Yukawa interaction as the minimal supersymmetric
standard model (MSSM). On the other hand, in the Type-X THDM, additional Higgs
bosons can predominantly decay into leptons. This scenario may be interesting
because of the motivation for a light charged Higgs boson scenario such as in
the TeV scale model of neutrino, dark matter and baryogenesis. We study how we
can distinguish the Type-X THDM from the MSSM at the Large Hadron Collider and
the International Linear Collider.Comment: 33 pages, 41 eps files, version accepted for publication in Physical
Review
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