125388267
Minimal dilaton model
Both the ATLAS and CMS experiments at the LHC have reported the observation of the particle of mass around 125 GeV which is consistent to the Standard Model (SM) Higgs boson, but with an excess of events beyond the SM expectation in the diphoton decay channel at each of them. There still remains room for a logical possibility that we are not seeing the SM Higgs but something else. Here we introduce the minimal dilaton model in which the LHC signals are explained by an extra singlet scalar of the mass around 125 GeV that slightly mixes with the SM Higgs heavier than 600 GeV. When this scalar has a vacuum expectation value well beyond the electroweak scale, it can be identified as a linearly realized version of a dilaton field. Though the current experimental constraints from the Higgs search disfavors such a region, the singlet scalar model itself still provides a viable alternative to the SM Higgs in interpreting its search results.
85538675
Phenomenology of Partially Composite Standard Model
We propose a model to describe the low energy physics of partially composite Standard Model, in which the electroweak sector in the Standard Model is weakly coupled to some strong dynamics. The vector resonances in the strong sector are introduced as the effective degrees of freedom, W' and Z', which mixes with the W and Z bosons through the electroweak symmetry breaking. Through the coupling to the strong sector, the Standard Model Higgs boson becomes partially composite, and its properties are modified. We study the constraints from the electroweak precision data and direct searches of W' and Z' at the LHC expriments, and discuss the effects on the production/decay properties of the Higgs boson.
119177190
Probing LHC Higgs Signals from Extended Electroweak Gauge Group
We study the effects of the extended electroweak gauge sector on the signal strengths of the Higgs boson at the LHC. Extension of the Higgs sector associate with the extension of the electroweak gauge symmetry. In our setup, there are two neutral Higgs states ($h$, $H$) and three new gauge bosons ($W'^{\pm}$, $Z'$). We assume the lightest scalar, $h$, is what LHC found and its mass is 125 GeV. We find the enhancement of $\mu(gg \to h \to \gamma \gamma)$. On the other hand, other decay processes are same as or smaller than the SM expectation.
125388267
Minimal dilaton model
Both the ATLAS and CMS experiments at the LHC have reported the observation of the particle of mass around 125 GeV which is consistent to the Standard Model (SM) Higgs boson, but with an excess of events beyond the SM expectation in the diphoton decay channel at each of them. There still remains room for a logical possibility that we are not seeing the SM Higgs but something else. Here we introduce the minimal dilaton model in which the LHC signals are explained by an extra singlet scalar of the mass around 125 GeV that slightly mixes with the SM Higgs heavier than 600 GeV. When this scalar has a vacuum expectation value well beyond the electroweak scale, it can be identified as a linearly realized version of a dilaton field. Though the current experimental constraints from the Higgs search disfavors such a region, the singlet scalar model itself still provides a viable alternative to the SM Higgs in interpreting its search results.
118433920
Drell-Yan production ofZ′in the three-site Higgsless model at the LHC
In the Higgsless models, there are extra gauge bosons which keep the perturbative unitarity of a longitudinally polarized gauge boson. The three-site Higgsless model is a minimal Higgsless model and contains three extra gauge bosons, $W^{\prime \pm}$ and Z'. In this paper, we report the discovery potential of the Z' gauge boson via Drell-Yan production with Z'(mass=380, 500, 600 GeV) $\rightarrow WW \rightarrow \ell\nu qq$ ($\ell=e$, $\mu$) at the LHC ($\sqrt{s}$=14 TeV).
118519668
The Flavor Structure of the Three-Site Higgsless Model
We study the flavor structure of the three-site Higgsless model and evaluate the constraints on the model arising from flavor physics. We find that current data constrain the model to exhibit only minimal flavor violation at tree level. Moreover, at the one-loop level, by studying the leading chiral logarithmic corrections to chirality-preserving Delta F = 1 and Delta F = 2 processes from new physics in the model, we show that the combination of minimal flavor violation and ideal delocalization ensures that these flavor-changing effects are sufficiently small that the model remains phenomenologically viable.
119190303
Novel extrapolation method in the Monte Carlo shell model
We propose an extrapolation method utilizing energy variance in the Monte Carlo shell model to estimate the energy eigenvalue and observables accurately. We derive a formula for the energy variance with deformed Slater determinants, which enables us to calculate the energy variance efficiently. The feasibility of the method is demonstrated for the full pf-shell calculation of {sup 56}Ni, and the applicability of the method to a system beyond the current limit of exact diagonalization is shown for the pf+g{sub 9/2}-shell calculation of {sup 64}Ge.
120739371
High gradient test at Nextef and high-power long-term operation of devices
Abstract The X-band high gradient studies at Nextef, the 100 MW X-Band test station in KEK operated since 2008, is reviewed. Recent high power test results of TD18#2, an 18-cell CLIC prototype structure with HOM damping slots, are given. The measured breakdown rate is ∼10 −5 /pulse/m under the operation at 100 MV/m gradient with 250 ns rf pulse width. The rate is higher by one- to two-order compared with that of the T18 structure, which is a disk loaded structure without the HOM slots. The recent performance of the station is also reviewed, especially that of PPM klystrons is discussed. An overview of our on-going programs such as the pulse compression system of Nextef as well as the future plans of X-band study is given.
119017224
Estimation of synchrotron-radiation background based on a real beam orbit
Some high-energy experiments have suffered from synchrotron-radiation background. As a measure, we have developed a new calculation method of synchrotron radiation based on a real beam orbit, aiming at quantitative estimations and the construction of a possible alarm system for the background. An explanation and a demonstration of our method are given.
121471479
Multipactoring zone map of an rf input coupler and its application to high beam current storage rings
123321012
Performance and operation results of the RF systems at the KEK B-Factory
KEK B-Factory (KEKB) was terminated in 2010 after achieving the world record luminosity of 2.11 × 1034 cm−2s−1. This paper describes the design features, performance, and operation results of the KEKB RF systems, which include a lot of original RF technologies and methods to store an electron/positron beam over 1 A stably. To cope with beam instabilities caused by large beam currents, two new types of normal and superconducting (SC) cavities with large stored energy were developed and successfully operated. For a new beam colliding scheme called crab crossing, two SC crab cavities were introduced and boosted the peak luminosity. Performance of these cavities is reported, along with the lowlevel and high-power RF systems, and the cryogenic system for the SC cavities. The status of the RF system upgrade towards SuperKEKB, which aims at a luminosity of 8.0 × 1035 cm−2s−1, is briefly described. © The Author(s) 2013. Published by Oxford University Press on behalf of the Physical Society of Japan. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department. Copyright © 2013 The Physical Society of Japan Other Oxford University Press sites: Oxford University Press