56 research outputs found
Lepton-Flavour-Violation in SUSY Models with and without R-parity
We discuss Lepton-Flavour-Violating phenomena such as ,
, and conversion in nuclei in SUSY models with and
without R-parity. We stress that experimental searches for all the LFV
processes are important to distinguish between the different models.Comment: 4 pages, talk given at 8th International Workshop on Deep Inelastic
Scattering and QCD (DIS 2000), Liverpool, England, 25-30 Apr 200
Michel parameters for decays in a general two Higgs doublet model with flavor violation
In a general two Higgs doublet model (2HDM), the anomaly of muon anomalous
magnetic moment (muon g-2) can be explained by flavor violating
Yukawa couplings, motivated by the recent CMS excess in Higgs boson decay
. We study Michel parameters for decays in the 2HDM with the lepton flavor
violation, and show that they can be sensitive to the flavor structure as well
as the Lorentz and chiral structures of the model. We find that the correction
to the Michel parameter in is
correlated to the contribution to the muon g-2, and it can be as large as
in the parameter region where the flavor violating
Yukawa couplings explain the muon g-2 anomaly. Therefore the precision
measurement of the Michel parameter at the level of would
significantly probe the interesting parameter space for the solution to the
muon g-2 anomaly.Comment: 16 pages, 2 figure
New physics for muon anomalous magnetic moment and its electroweak precision analysis
About 3 sigma deviation from the standard model prediction of muon anomalous
magnetic moment (muon g-2) has been reported. We consider new physics beyond
the standard model which has new Yukawa interactions with muon. We compute new
contributions to muon g-2 and corrections to electroweak observables, and show
the consistent region of parameter space. We find that in a simple model where
the chirality flip of muon occurs only in the external muon line in one-loop
muon g-2 diagrams, it is necessary to introduce the relatively large new Yukawa
coupling and the electroweak scale new particles. On the other hand, in a model
where the chirality flip can occur in the internal fermion line of one loop
muon g-2 diagrams, we can obtain favorable g-2 contributions without large
Yukawa coupling, and they are consistent with the precision electroweak
observables. Finally, we discuss effects of new particles for muon g-2 on the
Higgs boson decay h to 2 photons and direct productions of these particles at
the LHC experiment.Comment: 31 pages, 20 figure
Lepton-flavor-violating Higgs decay and muon anomalous magnetic moment in a general two Higgs doublet model
A two Higgs doublet model (2HDM) is one of the minimal extensions of the
Standard Model (SM), and it is well-known that the general setup predicts the
flavor-violating phenomena, mediated by neutral Higgs interactions. Recently
the CMS collaboration has reported an excess of the lepton-flavor-violating
Higgs decay in channel with a significance of 2.5 . We investigate the CMS excess in a general 2HDM with tree-level Flavor
Changing Neutral Currents (FCNCs), and discuss its impact on the other physical
observations. Especially, we see that the FCNCs relevant to the excess can
enhance the neutral Higgs contributions to the muon anomalous magnetic moment,
and can resolve the discrepancy between the measured value and the SM
prediction. We also find that the couplings to be consistent with the muon g-2
anomaly as well as the CMS excess in predict the sizable
rate of , which is within the reach of future B
factory.Comment: 6 pages, 3 figures, revised Fig.3, corrected Eq. (12), added
references, accepted for publication in JHE
Muon g-2 and LHC phenomenology in the gauge symmetric model
In this paper, we consider phenomenology of a model with an
gauge symmetry. Since the muon couples to the gauge boson
(called boson), its contribution to the muon anomalous magnetic moment
(muon g-2) can account for the discrepancy between the standard model
prediction and the experimental measurements. On the other hand, the
boson does not interact with the electron and quarks, and hence there are no
strong constraints from collider experiments even if the boson mass is of
the order of the electroweak scale. We show an allowed region of a parameter
space in the symmetric model, taking into account consistency
with the electroweak precision measurements as well as the muon g-2. We study
the Large Hadron Collider (LHC) phenomenology, and show that the current and
future data would probe the interesting parameter space for this model.Comment: 26 pages, 12 figure
Extended UDP Multiple Hole Punching Method to Traverse Large Scale NATs
A Network Address Translator (NAT) is a popular technological tool used in networks, especially in small-sized networks. Recently, network operators have been considering deploying Large Scale NATs (LSNs) to cope with IPv4 address pool exhaustion. This will make it necessary to deal with several problems related to LSNs, such as multiple levels of NATs (cascaded NATs) and the shortage of port numbers used by NATs. To address these issues, this paper extends the concept of UDP Multiple Hole Punching previously proposed by us. The use of our proposed method enables an accurate Port Prediction and reduces the number of open ports. The new method can determine the low TTL values for IP packets. We also discuss the application of i-Path routers, which provide status information about NATs along a network path for end hosts. The use of these routers makes it easier to perform NAT traversal
Testing the Littlest Higgs Model with T-parity at the Large Hadron Collider
In the framework of the littlest Higgs model with T-parity (LHT), we study
the production processes of T-even (T_+) and T-odd (T_-) partners of the top
quark at the Large Hadron Collider (LHC). We show that the signal events can be
distinguished from the standard-model backgrounds, and that information about
mass and mixing parameters of the top partners can be measured with relatively
good accuracies. With the measurements of these parameters, we show that a
non-trivial test of the LHT can be performed. We also discuss a possibility to
reconstruct the thermal relic density of the lightest T-odd particle A_H using
the LHC results, and show that the scenario where A_H becomes dark matter may
be checked.Comment: 26 pages, 6 figure
Dynamical SUSY Breaking with a Hybrid Messenger Sector
In this paper we present a dynamical model of SUSY breaking with a hybrid
messenger sector. SUSY is broken dynamically at a scale of order GeV via
strong SU(2) gauge interactions. SUSY breaking is then transmitted to the
observable sector via two distinct sources: (1) messengers, carrying Standard
Model gauge quantum numbers, with the messenger mass of order
GeV, and (2) the D term of an anomalous U(1). The model is
quite constrained. The messenger scale is fixed by the Fayet-Iliopoulos term
for the anomalous U(1) interaction. In addition, we show that the D term
SUSY breaking contributions to squark and slepton masses are "naturally" the
same order as those coming from the messengers.Comment: 14 pages, 1 figur
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