1,897 research outputs found
Higgs Physics as a Proble of New Physics
The discovery of the Higgs boson at the LHC has opened the door to clarify
the mechanism of electroweak symmetry breaking and the origin of masses of
particles. The Higgs sector in the SM is the simplest but has no theoretical
principle, so that there is a possibility of non-minimal Higgs sectors. While
the standard model is not contradict with the current data at the LHC within
the error, most of extended Higgs sectors can also reproduce the data. An
extended Higgs sector often appears in a new physics model beyond the standard
model, so that we can determine new physics from the Higgs sector. In this
talk, we discuss various aspects of extended Higgs sectors, in particular its
phenomenological properties and testability at future experiments at the
International Linear Collider.Comment: 6 pages, 3 figures, prepared for Proceedings of LC13 Workshop:
exploring QCD from the infrared regime to heavy flavour scales at
B-factories, the LHC and a Linear Collider, 16-20 September 2013, ECT*, Villa
Tambosi, Villazzano (TN), Ital
Search for lepton flavor violation via the intense high-energy muon beam
A deep inerastic scattering process \mutau is discussed to study lepton
flavor violation between muons and tau leptons. In supersymmetric models, the
Higgs boson mediated diagrams could be important for this reaction. We find
that at a muon energy () higher than 50 GeV, the predicted cross
section significantly increases due to the contribution from sea -quarks.
The number of produced tau leptons can be at = 300
GeV from muons, whereas events are given at
GeV.Comment: Contribution to the 6th International Workshop on Neutrino Factories
& Superbeams(NuFact04), Jul. 26-Aug. 1, 2004, Osaka Univerisity, Osaka,
Japan, talk given by S.K., to appear in the Proceedings, 3 pages, 4 figure
The vertex and single charged Higgs boson production via fusion at the Large Hadron Collider
There is a variety of new physics scenarios which deduce extended Higgs
sectors in the low energy effective theory. The coupling of a singly-charged
Higgs boson () with weak gauge bosons, , directly
depends on the global symmetry structure of the model, so that its experimental
determination can be useful to test each scenario. We discuss predictions on
this coupling in several models, such as the model with additional real and
complex triplets, the Littlest Higgs model, the two Higgs doublet model and the
minimal supersymmetric standard model. In order to measure the coupling we consider single production via the fusion
mechanism at the CERN Large Hadron Collider. The production rate is
hierarchically different among these models, so that this process can be useful
to explore new physics scenarios.Comment: 14 pages, 2 figures, revtex4, references added, typo correcte
Probing Models of Neutrino Masses via the Flavor Structure of the Mass Matrix
We discuss what kinds of combinations of Yukawa interactions can generate the
Majorana neutrino mass matrix. We concentrate on the flavor structure of the
neutrino mass matrix because it does not depend on details of the models except
for Yukawa interactions while determination of the overall scale of the mass
matrix requires to specify also the scalar potential and masses of new
particles. Thus, models to generate Majorana neutrino mass matrix can be
efficiently classified according to the combination of Yukawa interactions. We
first investigate the case where Yukawa interactions with only leptons are
utilized. Next, we consider the case with Yukawa interactions between leptons
and gauge singlet fermions, which have the odd parity under the unbroken Z_2
symmetry. We show that combinations of Yukawa interactions for these cases can
be classified into only three groups. Our classification would be useful for
the efficient discrimination of models via experimental tests for not each
model but just three groups of models.Comment: 14 pages, 9 eps files, references adde
Unitarity bound in the most general two Higgs doublet model
We investigate unitarity bounds in the most general two Higgs doublet model
without a discrete symmetry nor CP conservation. S-wave amplitudes for
two-body elastic scatterings of Nambu-Goldstone bosons and physical Higgs
bosons are calculated at high energies for all possible initial and final
states (14 neutral, 8 singly-charged and 3 doubly-charged states). We obtain
analytic formulae for the block-diagonalized scattering matrix by the
classification of the two body scattering states using the conserved quantum
numbers at high energies. Imposing the condition of perturbative unitarity to
the eigenvalues of the scattering matrix, constraints on the model parameters
can be obtained. We apply our results to constrain the mass range of the
next--to--lightest Higgs state in the model.Comment: Version published in Physics Letters
Heavy charged Higgs boson production at next generation colliders
We investigate the scope of all relevant production modes of charged Higgs
bosons in the MSSM, with mass larger than the one of the top quark, at future
Linear Colliders operating in mode at the TeV energy scale.
Final states with one or two bosons are considered, as produced by both
tree- and loop-level interactionsComment: 11 pages, latex, 6 figure
Higgs boson pair production at a photon-photon collision in the two Higgs doublet model
We calculate the cross section of Higgs boson pair production at a photon
collider in the two Higgs doublet model. We focus on the scenario in which the
lightest CP even Higgs boson () has the standard model like couplings to the
gauge bosons. We take into account the one-loop correction to the
coupling as well as additional one-loop diagrams due to charged Higgs bosons to
the helicity amplitudes. It is found that the full cross
section can be enhanced by both these effects to a considerable level. We
discuss the impact of these corrections on the coupling measurement at
the photon collider.Comment: 16 pages, 8 figures; added Appendix with a figur
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